iio: ad9361: Make sure the part is in the desired ENSM state #36
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lclausen-adi
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Jan 25, 2018
mhennerich
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stefpopa
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Jan 25, 2018
commodo
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Jan 25, 2018
drivers/iio/adc/ad9361.c
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| rc = ad9361_spi_write(spi, REG_ENSM_CONFIG_1, val); | ||
| if (rc) | ||
| if (rc) { | ||
| dev_err(dev, "Failed to restore state\n"); |
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i'd change the message here to make it clear that it was an SPI write err vs a more generic error;
at debug time, this can be confused with the message bellow, which is the same
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Agree, it will be changed to:
dev_err(dev, "Failed to write ENSM_CONFIG_1");
Thanks
commodo
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drivers/iio/adc/ad9361.c
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|
|
||
| do { | ||
| mdelay(1); | ||
| } while (ad9361_ensm_get_state(phy) != ensm_state && --timeout); |
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this loop would always wait at least 1 millisecond, even if [potentially] the state has changed already ;
curios: could it happen that the state is set sooner than 1 millisecond ?
if yes, it could be a small improvement to invert the condition and do
while (ad9361_ensm_get_state(phy) != ensm_state && timeout--) {
mdelay(1);
}
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The 1 millisecond delay is not mandatory - it depends on the state/platform. It's a good remark and I will change the commit accordingly.
Thanks
ad9361_ensm_force_state() should verify if the part is really in the desired ENSM state before exit. Otherwise, other operations that are executed afterwards may fail. Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
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KASAN detected slab-out-of-bounds access in printk from overlayfs, because string format used %*s instead of %.*s. > BUG: KASAN: slab-out-of-bounds in string+0x298/0x2d0 lib/vsprintf.c:604 > Read of size 1 at addr ffff8801c36c66ba by task syz-executor2/27811 > > CPU: 0 PID: 27811 Comm: syz-executor2 Not tainted 4.19.0-rc5+ #36 ... > printk+0xa7/0xcf kernel/printk/printk.c:1996 > ovl_lookup_index.cold.15+0xe8/0x1f8 fs/overlayfs/namei.c:689 Reported-by: syzbot+376cea2b0ef340db3dd4@syzkaller.appspotmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 359f392 ("ovl: lookup index entry for copy up origin") Cc: <stable@vger.kernel.org> # v4.13
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The current code that checks for misspelling verifies, in a more complex regex, if $rawline matches [^\w]($misspellings)[^\w] Being $rawline a byte-string, a utf-8 character in $rawline can match the non-word-char [^\w]. E.g.: ./scripts/checkpatch.pl --git 81c2f05 WARNING: 'ment' may be misspelled - perhaps 'meant'? #36: FILE: MAINTAINERS:14360: +M: Clément Léger <clement.leger@bootlin.com> ^^^^ Use a utf-8 version of $rawline for spell checking. Link: https://lkml.kernel.org/r/20250616-b4-checkpatch-upstream-v2-1-5600ce4a3b43@foss.st.com Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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[ Upstream commit eedf3e3 ] ACPICA commit 1c28da2242783579d59767617121035dafba18c3 This was originally done in NetBSD: NetBSD/src@b69d1ac and is the correct alternative to the smattering of `memcpy`s I previously contributed to this repository. This also sidesteps the newly strict checks added in UBSAN: llvm/llvm-project@7926744 Before this change we see the following UBSAN stack trace in Fuchsia: #0 0x000021afcfdeca5e in acpi_rs_get_address_common(struct acpi_resource*, union aml_resource*) ../../third_party/acpica/source/components/resources/rsaddr.c:329 <platform-bus-x86.so>+0x6aca5e #1.2 0x000021982bc4af3c in ubsan_get_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:41 <libclang_rt.asan.so>+0x41f3c #1.1 0x000021982bc4af3c in maybe_print_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:51 <libclang_rt.asan.so>+0x41f3c #1 0x000021982bc4af3c in ~scoped_report() compiler-rt/lib/ubsan/ubsan_diag.cpp:395 <libclang_rt.asan.so>+0x41f3c #2 0x000021982bc4bb6f in handletype_mismatch_impl() compiler-rt/lib/ubsan/ubsan_handlers.cpp:137 <libclang_rt.asan.so>+0x42b6f #3 0x000021982bc4b723 in __ubsan_handle_type_mismatch_v1 compiler-rt/lib/ubsan/ubsan_handlers.cpp:142 <libclang_rt.asan.so>+0x42723 #4 0x000021afcfdeca5e in acpi_rs_get_address_common(struct acpi_resource*, union aml_resource*) ../../third_party/acpica/source/components/resources/rsaddr.c:329 <platform-bus-x86.so>+0x6aca5e #5 0x000021afcfdf2089 in acpi_rs_convert_aml_to_resource(struct acpi_resource*, union aml_resource*, struct acpi_rsconvert_info*) ../../third_party/acpica/source/components/resources/rsmisc.c:355 <platform-bus-x86.so>+0x6b2089 #6 0x000021afcfded169 in acpi_rs_convert_aml_to_resources(u8*, u32, u32, u8, void**) ../../third_party/acpica/source/components/resources/rslist.c:137 <platform-bus-x86.so>+0x6ad169 #7 0x000021afcfe2d24a in acpi_ut_walk_aml_resources(struct acpi_walk_state*, u8*, acpi_size, acpi_walk_aml_callback, void**) ../../third_party/acpica/source/components/utilities/utresrc.c:237 <platform-bus-x86.so>+0x6ed24a #8 0x000021afcfde66b7 in acpi_rs_create_resource_list(union acpi_operand_object*, struct acpi_buffer*) ../../third_party/acpica/source/components/resources/rscreate.c:199 <platform-bus-x86.so>+0x6a66b7 #9 0x000021afcfdf6979 in acpi_rs_get_method_data(acpi_handle, const char*, struct acpi_buffer*) ../../third_party/acpica/source/components/resources/rsutils.c:770 <platform-bus-x86.so>+0x6b6979 #10 0x000021afcfdf708f in acpi_walk_resources(acpi_handle, char*, acpi_walk_resource_callback, void*) ../../third_party/acpica/source/components/resources/rsxface.c:731 <platform-bus-x86.so>+0x6b708f #11 0x000021afcfa95dcf in acpi::acpi_impl::walk_resources(acpi::acpi_impl*, acpi_handle, const char*, acpi::Acpi::resources_callable) ../../src/devices/board/lib/acpi/acpi-impl.cc:41 <platform-bus-x86.so>+0x355dcf #12 0x000021afcfaa8278 in acpi::device_builder::gather_resources(acpi::device_builder*, acpi::Acpi*, fidl::any_arena&, acpi::Manager*, acpi::device_builder::gather_resources_callback) ../../src/devices/board/lib/acpi/device-builder.cc:84 <platform-bus-x86.so>+0x368278 #13 0x000021afcfbddb87 in acpi::Manager::configure_discovered_devices(acpi::Manager*) ../../src/devices/board/lib/acpi/manager.cc:75 <platform-bus-x86.so>+0x49db87 #14 0x000021afcf99091d in publish_acpi_devices(acpi::Manager*, zx_device_t*, zx_device_t*) ../../src/devices/board/drivers/x86/acpi-nswalk.cc:95 <platform-bus-x86.so>+0x25091d #15 0x000021afcf9c1d4e in x86::X86::do_init(x86::X86*) ../../src/devices/board/drivers/x86/x86.cc:60 <platform-bus-x86.so>+0x281d4e #16 0x000021afcf9e33ad in λ(x86::X86::ddk_init::(anon class)*) ../../src/devices/board/drivers/x86/x86.cc:77 <platform-bus-x86.so>+0x2a33ad #17 0x000021afcf9e313e in fit::internal::target<(lambda at../../src/devices/board/drivers/x86/x86.cc:76:19), false, false, std::__2::allocator<std::byte>, void>::invoke(void*) ../../sdk/lib/fit/include/lib/fit/internal/function.h:183 <platform-bus-x86.so>+0x2a313e #18 0x000021afcfbab4c7 in fit::internal::function_base<16UL, false, void(), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<16UL, false, void (), std::__2::allocator<std::byte> >*) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <platform-bus-x86.so>+0x46b4c7 #19 0x000021afcfbab342 in fit::function_impl<16UL, false, void(), std::__2::allocator<std::byte>>::operator()(const fit::function_impl<16UL, false, void (), std::__2::allocator<std::byte> >*) ../../sdk/lib/fit/include/lib/fit/function.h:315 <platform-bus-x86.so>+0x46b342 #20 0x000021afcfcd98c3 in async::internal::retained_task::Handler(async_dispatcher_t*, async_task_t*, zx_status_t) ../../sdk/lib/async/task.cc:24 <platform-bus-x86.so>+0x5998c3 #21 0x00002290f9924616 in λ(const driver_runtime::Dispatcher::post_task::(anon class)*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, zx_status_t) ../../src/devices/bin/driver_runtime/dispatcher.cc:789 <libdriver_runtime.so>+0x10a616 #22 0x00002290f9924323 in fit::internal::target<(lambda at../../src/devices/bin/driver_runtime/dispatcher.cc:788:7), true, false, std::__2::allocator<std::byte>, void, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int>::invoke(void*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/internal/function.h:128 <libdriver_runtime.so>+0x10a323 #23 0x00002290f9904b76 in fit::internal::function_base<24UL, true, void(std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<24UL, true, void (std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <libdriver_runtime.so>+0xeab76 #24 0x00002290f9904831 in fit::callback_impl<24UL, true, void(std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int), std::__2::allocator<std::byte>>::operator()(fit::callback_impl<24UL, true, void (std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/function.h:471 <libdriver_runtime.so>+0xea831 #25 0x00002290f98d5adc in driver_runtime::callback_request::Call(driver_runtime::callback_request*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, zx_status_t) ../../src/devices/bin/driver_runtime/callback_request.h:74 <libdriver_runtime.so>+0xbbadc #26 0x00002290f98e1e58 in driver_runtime::Dispatcher::dispatch_callback(driver_runtime::Dispatcher*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >) ../../src/devices/bin/driver_runtime/dispatcher.cc:1248 <libdriver_runtime.so>+0xc7e58 #27 0x00002290f98e4159 in driver_runtime::Dispatcher::dispatch_callbacks(driver_runtime::Dispatcher*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.cc:1308 <libdriver_runtime.so>+0xca159 #28 0x00002290f9918414 in λ(const driver_runtime::Dispatcher::create_with_adder::(anon class)*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.cc:353 <libdriver_runtime.so>+0xfe414 #29 0x00002290f991812d in fit::internal::target<(lambda at../../src/devices/bin/driver_runtime/dispatcher.cc:351:7), true, false, std::__2::allocator<std::byte>, void, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>>::invoke(void*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/internal/function.h:128 <libdriver_runtime.so>+0xfe12d #30 0x00002290f9906fc7 in fit::internal::function_base<8UL, true, void(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<8UL, true, void (std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <libdriver_runtime.so>+0xecfc7 #31 0x00002290f9906c66 in fit::function_impl<8UL, true, void(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte>>::operator()(const fit::function_impl<8UL, true, void (std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/function.h:315 <libdriver_runtime.so>+0xecc66 #32 0x00002290f98e73d9 in driver_runtime::Dispatcher::event_waiter::invoke_callback(driver_runtime::Dispatcher::event_waiter*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.h:543 <libdriver_runtime.so>+0xcd3d9 #33 0x00002290f98e700d in driver_runtime::Dispatcher::event_waiter::handle_event(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, async_dispatcher_t*, async::wait_base*, zx_status_t, zx_packet_signal_t const*) ../../src/devices/bin/driver_runtime/dispatcher.cc:1442 <libdriver_runtime.so>+0xcd00d #34 0x00002290f9918983 in async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>::handle_event(async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>*, async_dispatcher_t*, async::wait_base*, zx_status_t, zx_packet_signal_t const*) ../../src/devices/bin/driver_runtime/async_loop_owned_event_handler.h:59 <libdriver_runtime.so>+0xfe983 #35 0x00002290f9918b9e in async::wait_method<async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>, &async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>::handle_event>::call_handler(async_dispatcher_t*, async_wait_t*, zx_status_t, zx_packet_signal_t const*) ../../sdk/lib/async/include/lib/async/cpp/wait.h:201 <libdriver_runtime.so>+0xfeb9e #36 0x00002290f99bf509 in async_loop_dispatch_wait(async_loop_t*, async_wait_t*, zx_status_t, zx_packet_signal_t const*) ../../sdk/lib/async-loop/loop.c:394 <libdriver_runtime.so>+0x1a5509 #37 0x00002290f99b9958 in async_loop_run_once(async_loop_t*, zx_time_t) ../../sdk/lib/async-loop/loop.c:343 <libdriver_runtime.so>+0x19f958 #38 0x00002290f99b9247 in async_loop_run(async_loop_t*, zx_time_t, _Bool) ../../sdk/lib/async-loop/loop.c:301 <libdriver_runtime.so>+0x19f247 #39 0x00002290f99ba962 in async_loop_run_thread(void*) ../../sdk/lib/async-loop/loop.c:860 <libdriver_runtime.so>+0x1a0962 #40 0x000041afd176ef30 in start_c11(void*) ../../zircon/third_party/ulib/musl/pthread/pthread_create.c:63 <libc.so>+0x84f30 #41 0x000041afd18a448d in thread_trampoline(uintptr_t, uintptr_t) ../../zircon/system/ulib/runtime/thread.cc:100 <libc.so>+0x1ba48d Link: acpica/acpica@1c28da22 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/4664267.LvFx2qVVIh@rjwysocki.net Signed-off-by: Tamir Duberstein <tamird@gmail.com> [ rjw: Pick up the tag from Tamir ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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After hid_hw_start() is called hidinput_connect() will eventually be called to set up the device with the input layer since the HID_CONNECT_DEFAULT connect mask is used. During hidinput_connect() all input and output reports are processed and corresponding hid_inputs are allocated and configured via hidinput_configure_usages(). This process involves slot tagging report fields and configuring usages by setting relevant bits in the capability bitmaps. However it is possible that the capability bitmaps are not set at all leading to the subsequent hidinput_has_been_populated() check to fail leading to the freeing of the hid_input and the underlying input device. This becomes problematic because a malicious HID device like a ASUS ROG N-Key keyboard can trigger the above scenario via a specially crafted descriptor which then leads to a user-after-free when the name of the freed input device is written to later on after hid_hw_start(). Below, report 93 intentionally utilises the HID_UP_UNDEFINED Usage Page which is skipped during usage configuration, leading to the frees. 0x05, 0x0D, // Usage Page (Digitizer) 0x09, 0x05, // Usage (Touch Pad) 0xA1, 0x01, // Collection (Application) 0x85, 0x0D, // Report ID (13) 0x06, 0x00, 0xFF, // Usage Page (Vendor Defined 0xFF00) 0x09, 0xC5, // Usage (0xC5) 0x15, 0x00, // Logical Minimum (0) 0x26, 0xFF, 0x00, // Logical Maximum (255) 0x75, 0x08, // Report Size (8) 0x95, 0x04, // Report Count (4) 0xB1, 0x02, // Feature (Data,Var,Abs) 0x85, 0x5D, // Report ID (93) 0x06, 0x00, 0x00, // Usage Page (Undefined) 0x09, 0x01, // Usage (0x01) 0x15, 0x00, // Logical Minimum (0) 0x26, 0xFF, 0x00, // Logical Maximum (255) 0x75, 0x08, // Report Size (8) 0x95, 0x1B, // Report Count (27) 0x81, 0x02, // Input (Data,Var,Abs) 0xC0, // End Collection Below is the KASAN splat after triggering the UAF: [ 21.672709] ================================================================== [ 21.673700] BUG: KASAN: slab-use-after-free in asus_probe+0xeeb/0xf80 [ 21.673700] Write of size 8 at addr ffff88810a0ac000 by task kworker/1:2/54 [ 21.673700] [ 21.673700] CPU: 1 UID: 0 PID: 54 Comm: kworker/1:2 Not tainted 6.16.0-rc4-g9773391cf4dd-dirty #36 PREEMPT(voluntary) [ 21.673700] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 21.673700] Call Trace: [ 21.673700] <TASK> [ 21.673700] dump_stack_lvl+0x5f/0x80 [ 21.673700] print_report+0xd1/0x660 [ 21.673700] kasan_report+0xe5/0x120 [ 21.673700] __asan_report_store8_noabort+0x1b/0x30 [ 21.673700] asus_probe+0xeeb/0xf80 [ 21.673700] hid_device_probe+0x2ee/0x700 [ 21.673700] really_probe+0x1c6/0x6b0 [ 21.673700] __driver_probe_device+0x24f/0x310 [ 21.673700] driver_probe_device+0x4e/0x220 [...] [ 21.673700] [ 21.673700] Allocated by task 54: [ 21.673700] kasan_save_stack+0x3d/0x60 [ 21.673700] kasan_save_track+0x18/0x40 [ 21.673700] kasan_save_alloc_info+0x3b/0x50 [ 21.673700] __kasan_kmalloc+0x9c/0xa0 [ 21.673700] __kmalloc_cache_noprof+0x139/0x340 [ 21.673700] input_allocate_device+0x44/0x370 [ 21.673700] hidinput_connect+0xcb6/0x2630 [ 21.673700] hid_connect+0xf74/0x1d60 [ 21.673700] hid_hw_start+0x8c/0x110 [ 21.673700] asus_probe+0x5a3/0xf80 [ 21.673700] hid_device_probe+0x2ee/0x700 [ 21.673700] really_probe+0x1c6/0x6b0 [ 21.673700] __driver_probe_device+0x24f/0x310 [ 21.673700] driver_probe_device+0x4e/0x220 [...] [ 21.673700] [ 21.673700] Freed by task 54: [ 21.673700] kasan_save_stack+0x3d/0x60 [ 21.673700] kasan_save_track+0x18/0x40 [ 21.673700] kasan_save_free_info+0x3f/0x60 [ 21.673700] __kasan_slab_free+0x3c/0x50 [ 21.673700] kfree+0xcf/0x350 [ 21.673700] input_dev_release+0xab/0xd0 [ 21.673700] device_release+0x9f/0x220 [ 21.673700] kobject_put+0x12b/0x220 [ 21.673700] put_device+0x12/0x20 [ 21.673700] input_free_device+0x4c/0xb0 [ 21.673700] hidinput_connect+0x1862/0x2630 [ 21.673700] hid_connect+0xf74/0x1d60 [ 21.673700] hid_hw_start+0x8c/0x110 [ 21.673700] asus_probe+0x5a3/0xf80 [ 21.673700] hid_device_probe+0x2ee/0x700 [ 21.673700] really_probe+0x1c6/0x6b0 [ 21.673700] __driver_probe_device+0x24f/0x310 [ 21.673700] driver_probe_device+0x4e/0x220 [...] Fixes: 9ce12d8 ("HID: asus: Add i2c touchpad support") Cc: stable@vger.kernel.org Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> Link: https://patch.msgid.link/20250810181041.44874-1-qasdev00@gmail.com Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Sep 23, 2025
Patch series "mm: remove nth_page()", v2. As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #22 : disallow CMA allocations of non-contiguous pages Patch #23 -> #33 : sanity+check + remove nth_page() usage within SG entry Patch #34 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #35 : remove nth_page() in kfence Patch #36 : adjust stale comment regarding nth_page Patch #37 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. This patch (of 37): In an ideal world, we wouldn't have to deal with SPARSEMEM without SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is considered too costly and consequently not supported. However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just like we already do for arm64, s390 and x86. So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without SPARSEMEM_VMEMMAP. This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone for loongarch, powerpc, riscv and sparc. All architectures only enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big downside to using the VMEMMAP (quite the contrary). This is a preparation for not supporting (1) folio sizes that exceed a single memory section (2) CMA allocations of non-contiguous page ranges in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit possible impact as much as possible (e.g., gigantic hugetlb page allocations suddenly fails). Link: https://lkml.kernel.org/r/20250901150359.867252-1-david@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-2-david@redhat.com Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Alex Willamson <alex.williamson@redhat.com> Cc: Bart van Assche <bvanassche@acm.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brett Creeley <brett.creeley@amd.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter (Ampere) <cl@gentwo.org> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: James Bottomley <james.bottomley@HansenPartnership.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxim Levitky <maximlevitsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Niklas Cassel <cassel@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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ad9361_ensm_force_state() should verify if the part is really in the
desired ENSM state before exit. Otherwise, other operations that are
executed afterwards may fail.
Signed-off-by: Dragos Bogdan dragos.bogdan@analog.com