Update typo #386

colossus9 · 2017-01-30T22:20:48Z

Updating typo of help verbiage

KernelPRBot · 2017-01-31T04:00:08Z

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colossus9 · 2017-01-31T21:02:05Z

Thanks!

chrisfinazzo · 2017-02-09T19:50:39Z

This may be a question for the Trivial Patch Monkey (@jikos, I believe), but although the process to submit small patches is well documented, it makes little mention from what I can see about how Sphinx should be configured.

Is this simply a brew install sphinx-doc along with some flags to support the various architectures?

daxtens · 2017-02-09T20:49:57Z

That's an excellent question, and I don't know the answer off the top of my head - I'll find out and get back to you.

…

On Fri, Feb 10, 2017 at 6:52 AM, Chris Finazzo ***@***.***> wrote: This may be a question for the Trivial Patch Monkey ***@***.*** <https://github.com/jikos>, I believe), but although the process to submit small patches is well documented, it makes little mention from what I can see about how Sphinx should be configured. Is this simply a brew install sphinx sphinx-build along with some flags to support the various architectures? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#386 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ADJ5BRlxhmP8R7LglDC6faEUsHWJs6OLks5ra26bgaJpZM4Lx_jw> .

daxtens · 2017-02-10T01:35:57Z

So I don't have a macOS box handy to test brew, but it looks like installing sphinx is a pretty good start. I've been trying `make htmldocs` on my linux box, I found that I needed graphviz and xmlto as well. I know graphviz can be installed with `brew install graphviz`, not sure about xmlto. Hope this helps, let us know how you go.

…

On Fri, Feb 10, 2017 at 7:49 AM, Daniel Axtens ***@***.***> wrote: That's an excellent question, and I don't know the answer off the top of my head - I'll find out and get back to you. On Fri, Feb 10, 2017 at 6:52 AM, Chris Finazzo ***@***.***> wrote: > This may be a question for the Trivial Patch Monkey ***@***.*** > <https://github.com/jikos>, I believe), but although the process to > submit small patches is well documented, it makes little mention from what > I can see about how Sphinx should be configured. > > Is this simply a brew install sphinx sphinx-build along with some flags > to support the various architectures? > > — > You are receiving this because you were mentioned. > Reply to this email directly, view it on GitHub > <#386 (comment)>, or mute > the thread > <https://github.com/notifications/unsubscribe-auth/ADJ5BRlxhmP8R7LglDC6faEUsHWJs6OLks5ra26bgaJpZM4Lx_jw> > . >

lkl: Support multiple routing tables

The sub-programs prog->aux->poke_tab[] is populated in jit_subprogs() and then used when emitting 'BPF_JMP|BPF_TAIL_CALL' insn->code from the individual JITs. The poke_tab[] to use is stored in the insn->imm by the code adding it to that array slot. The JIT then uses imm to find the right entry for an individual instruction. In the x86 bpf_jit_comp.c this is done by calling emit_bpf_tail_call_direct with the poke_tab[] of the imm value. However, we observed the below null-ptr-deref when mixing tail call programs with subprog programs. For this to happen we just need to mix bpf-2-bpf calls and tailcalls with some extra calls or instructions that would be patched later by one of the fixup routines. So whats happening? Before the fixup_call_args() -- where the jit op is done -- various code patching is done by do_misc_fixups(). This may increase the insn count, for example when we patch map_lookup_up using map_gen_lookup hook. This does two things. First, it means the instruction index, insn_idx field, of a tail call instruction will move by a 'delta'. In verifier code, struct bpf_jit_poke_descriptor desc = { .reason = BPF_POKE_REASON_TAIL_CALL, .tail_call.map = BPF_MAP_PTR(aux->map_ptr_state), .tail_call.key = bpf_map_key_immediate(aux), .insn_idx = i + delta, }; Then subprog start values subprog_info[i].start will be updated with the delta and any poke descriptor index will also be updated with the delta in adjust_poke_desc(). If we look at the adjust subprog starts though we see its only adjusted when the delta occurs before the new instructions, /* NOTE: fake 'exit' subprog should be updated as well. */ for (i = 0; i <= env->subprog_cnt; i++) { if (env->subprog_info[i].start <= off) continue; Earlier subprograms are not changed because their start values are not moved. But, adjust_poke_desc() does the offset + delta indiscriminately. The result is poke descriptors are potentially corrupted. Then in jit_subprogs() we only populate the poke_tab[] when the above insn_idx is less than the next subprogram start. From above we corrupted our insn_idx so we might incorrectly assume a poke descriptor is not used in a subprogram omitting it from the subprogram. And finally when the jit runs it does the deref of poke_tab when emitting the instruction and crashes with below. Because earlier step omitted the poke descriptor. The fix is straight forward with above context. Simply move same logic from adjust_subprog_starts() into adjust_poke_descs() and only adjust insn_idx when needed. [ 82.396354] bpf_testmod: version magic '5.12.0-rc2alu+ SMP preempt mod_unload ' should be '5.12.0+ SMP preempt mod_unload ' [ 82.623001] loop10: detected capacity change from 0 to 8 [ 88.487424] ================================================================== [ 88.487438] BUG: KASAN: null-ptr-deref in do_jit+0x184a/0x3290 [ 88.487455] Write of size 8 at addr 0000000000000008 by task test_progs/5295 [ 88.487471] CPU: 7 PID: 5295 Comm: test_progs Tainted: G I 5.12.0+ torvalds#386 [ 88.487483] Hardware name: Dell Inc. Precision 5820 Tower/002KVM, BIOS 1.9.2 01/24/2019 [ 88.487490] Call Trace: [ 88.487498] dump_stack+0x93/0xc2 [ 88.487515] kasan_report.cold+0x5f/0xd8 [ 88.487530] ? do_jit+0x184a/0x3290 [ 88.487542] do_jit+0x184a/0x3290 ... [ 88.487709] bpf_int_jit_compile+0x248/0x810 ... [ 88.487765] bpf_check+0x3718/0x5140 ... [ 88.487920] bpf_prog_load+0xa22/0xf10 Reported-by: Jussi Maki <joamaki@gmail.com> CC: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Fixes: a748c69 ("bpf: propagate poke descriptors to subprograms") Reviewed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com>

The sub-programs prog->aux->poke_tab[] is populated in jit_subprogs() and then used when emitting 'BPF_JMP|BPF_TAIL_CALL' insn->code from the individual JITs. The poke_tab[] to use is stored in the insn->imm by the code adding it to that array slot. The JIT then uses imm to find the right entry for an individual instruction. In the x86 bpf_jit_comp.c this is done by calling emit_bpf_tail_call_direct with the poke_tab[] of the imm value. However, we observed the below null-ptr-deref when mixing tail call programs with subprog programs. For this to happen we just need to mix bpf-2-bpf calls and tailcalls with some extra calls or instructions that would be patched later by one of the fixup routines. So whats happening? Before the fixup_call_args() -- where the jit op is done -- various code patching is done by do_misc_fixups(). This may increase the insn count, for example when we patch map_lookup_up using map_gen_lookup hook. This does two things. First, it means the instruction index, insn_idx field, of a tail call instruction will move by a 'delta'. In verifier code, struct bpf_jit_poke_descriptor desc = { .reason = BPF_POKE_REASON_TAIL_CALL, .tail_call.map = BPF_MAP_PTR(aux->map_ptr_state), .tail_call.key = bpf_map_key_immediate(aux), .insn_idx = i + delta, }; Then subprog start values subprog_info[i].start will be updated with the delta and any poke descriptor index will also be updated with the delta in adjust_poke_desc(). If we look at the adjust subprog starts though we see its only adjusted when the delta occurs before the new instructions, /* NOTE: fake 'exit' subprog should be updated as well. */ for (i = 0; i <= env->subprog_cnt; i++) { if (env->subprog_info[i].start <= off) continue; Earlier subprograms are not changed because their start values are not moved. But, adjust_poke_desc() does the offset + delta indiscriminately. The result is poke descriptors are potentially corrupted. Then in jit_subprogs() we only populate the poke_tab[] when the above insn_idx is less than the next subprogram start. From above we corrupted our insn_idx so we might incorrectly assume a poke descriptor is not used in a subprogram omitting it from the subprogram. And finally when the jit runs it does the deref of poke_tab when emitting the instruction and crashes with below. Because earlier step omitted the poke descriptor. The fix is straight forward with above context. Simply move same logic from adjust_subprog_starts() into adjust_poke_descs() and only adjust insn_idx when needed. [ 82.396354] bpf_testmod: version magic '5.12.0-rc2alu+ SMP preempt mod_unload ' should be '5.12.0+ SMP preempt mod_unload ' [ 82.623001] loop10: detected capacity change from 0 to 8 [ 88.487424] ================================================================== [ 88.487438] BUG: KASAN: null-ptr-deref in do_jit+0x184a/0x3290 [ 88.487455] Write of size 8 at addr 0000000000000008 by task test_progs/5295 [ 88.487471] CPU: 7 PID: 5295 Comm: test_progs Tainted: G I 5.12.0+ torvalds#386 [ 88.487483] Hardware name: Dell Inc. Precision 5820 Tower/002KVM, BIOS 1.9.2 01/24/2019 [ 88.487490] Call Trace: [ 88.487498] dump_stack+0x93/0xc2 [ 88.487515] kasan_report.cold+0x5f/0xd8 [ 88.487530] ? do_jit+0x184a/0x3290 [ 88.487542] do_jit+0x184a/0x3290 ... [ 88.487709] bpf_int_jit_compile+0x248/0x810 ... [ 88.487765] bpf_check+0x3718/0x5140 ... [ 88.487920] bpf_prog_load+0xa22/0xf10 Fixes: a748c69 ("bpf: propagate poke descriptors to subprograms") Reported-by: Jussi Maki <joamaki@gmail.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Daniel Borkmann <daniel@iogearbox.net>

rust: enhance `PointerWrapper`.

[ Upstream commit 7506d21 ] The sub-programs prog->aux->poke_tab[] is populated in jit_subprogs() and then used when emitting 'BPF_JMP|BPF_TAIL_CALL' insn->code from the individual JITs. The poke_tab[] to use is stored in the insn->imm by the code adding it to that array slot. The JIT then uses imm to find the right entry for an individual instruction. In the x86 bpf_jit_comp.c this is done by calling emit_bpf_tail_call_direct with the poke_tab[] of the imm value. However, we observed the below null-ptr-deref when mixing tail call programs with subprog programs. For this to happen we just need to mix bpf-2-bpf calls and tailcalls with some extra calls or instructions that would be patched later by one of the fixup routines. So whats happening? Before the fixup_call_args() -- where the jit op is done -- various code patching is done by do_misc_fixups(). This may increase the insn count, for example when we patch map_lookup_up using map_gen_lookup hook. This does two things. First, it means the instruction index, insn_idx field, of a tail call instruction will move by a 'delta'. In verifier code, struct bpf_jit_poke_descriptor desc = { .reason = BPF_POKE_REASON_TAIL_CALL, .tail_call.map = BPF_MAP_PTR(aux->map_ptr_state), .tail_call.key = bpf_map_key_immediate(aux), .insn_idx = i + delta, }; Then subprog start values subprog_info[i].start will be updated with the delta and any poke descriptor index will also be updated with the delta in adjust_poke_desc(). If we look at the adjust subprog starts though we see its only adjusted when the delta occurs before the new instructions, /* NOTE: fake 'exit' subprog should be updated as well. */ for (i = 0; i <= env->subprog_cnt; i++) { if (env->subprog_info[i].start <= off) continue; Earlier subprograms are not changed because their start values are not moved. But, adjust_poke_desc() does the offset + delta indiscriminately. The result is poke descriptors are potentially corrupted. Then in jit_subprogs() we only populate the poke_tab[] when the above insn_idx is less than the next subprogram start. From above we corrupted our insn_idx so we might incorrectly assume a poke descriptor is not used in a subprogram omitting it from the subprogram. And finally when the jit runs it does the deref of poke_tab when emitting the instruction and crashes with below. Because earlier step omitted the poke descriptor. The fix is straight forward with above context. Simply move same logic from adjust_subprog_starts() into adjust_poke_descs() and only adjust insn_idx when needed. [ 82.396354] bpf_testmod: version magic '5.12.0-rc2alu+ SMP preempt mod_unload ' should be '5.12.0+ SMP preempt mod_unload ' [ 82.623001] loop10: detected capacity change from 0 to 8 [ 88.487424] ================================================================== [ 88.487438] BUG: KASAN: null-ptr-deref in do_jit+0x184a/0x3290 [ 88.487455] Write of size 8 at addr 0000000000000008 by task test_progs/5295 [ 88.487471] CPU: 7 PID: 5295 Comm: test_progs Tainted: G I 5.12.0+ torvalds#386 [ 88.487483] Hardware name: Dell Inc. Precision 5820 Tower/002KVM, BIOS 1.9.2 01/24/2019 [ 88.487490] Call Trace: [ 88.487498] dump_stack+0x93/0xc2 [ 88.487515] kasan_report.cold+0x5f/0xd8 [ 88.487530] ? do_jit+0x184a/0x3290 [ 88.487542] do_jit+0x184a/0x3290 ... [ 88.487709] bpf_int_jit_compile+0x248/0x810 ... [ 88.487765] bpf_check+0x3718/0x5140 ... [ 88.487920] bpf_prog_load+0xa22/0xf10 Fixes: a748c69 ("bpf: propagate poke descriptors to subprograms") Reported-by: Jussi Maki <joamaki@gmail.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org>

Update typo

b4b7ab1

Mic92 pushed a commit to Mic92/linux that referenced this pull request Feb 4, 2019

Merge pull request torvalds#386 from motomuman/netlink-policy-routing

b4967b0

lkl: Support multiple routing tables

ghost approved these changes Feb 15, 2020

View reviewed changes

TheSven73 pushed a commit to TheSven73/linux that referenced this pull request Jun 23, 2021

Merge pull request torvalds#386 from wedsonaf/borrowed

3c47616

rust: enhance `PointerWrapper`.

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Update typo #386

Update typo #386

colossus9 commented Jan 30, 2017 •

edited

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KernelPRBot commented Jan 31, 2017

colossus9 commented Jan 31, 2017

chrisfinazzo commented Feb 9, 2017 •

edited

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daxtens commented Feb 9, 2017 via email

daxtens commented Feb 10, 2017 via email

Update typo #386

Are you sure you want to change the base?

Update typo #386

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colossus9 commented Jan 30, 2017 • edited Loading

KernelPRBot commented Jan 31, 2017

How do I format my contribution?

Who do I send my contribution to?

How do I send my contribution?

How do I get help if I'm stuck?

I sent my patch - now what?

Further information

colossus9 commented Jan 31, 2017

chrisfinazzo commented Feb 9, 2017 • edited Loading

daxtens commented Feb 9, 2017 via email

daxtens commented Feb 10, 2017 via email

colossus9 commented Jan 30, 2017 •

edited

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chrisfinazzo commented Feb 9, 2017 •

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