Replace fake flexible-array declarations with the DECLARE_FLEX_ARRAY() helper macro #193

GustavoARSilva · 2022-08-29T21:06:38Z

Dependent bugs:

Replace all fake flexible arrays (i.e. zero-length and one-element arrays) in unions and structs with the
DECLARE_FLEX_ARRAY() helper macro.

In cases where two or more flexible arrays are needed in a structure, all of them should be declared through the DECLARE_FLEX_ARRAY() helper and within a union. See:

diff --git a/include/linux/filter.h b/include/linux/filter.h
index 4a93c12543ee2..4298c5e428a37 100644
--- a/[include/linux/filter.h](https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/include/linux/filter.h?id=3080ea5553cc909b000d1f1d964a9041962f2c5b)
+++ b/[include/linux/filter.h](https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/include/linux/filter.h?id=fa7845cfd53f3b1d3f60efa55db89805595bc045)
@@ -586,8 +586,10 @@ struct bpf_prog {
 	struct bpf_prog_aux	*aux;		/* Auxiliary fields */
 	struct sock_fprog_kern	*orig_prog;	/* Original BPF program */
 	/* Instructions for interpreter */
-	struct sock_filter	insns[0];
-	struct bpf_insn		insnsi[];
+	union {
+		DECLARE_FLEX_ARRAY(struct sock_filter, insns);
+		DECLARE_FLEX_ARRAY(struct bpf_insn, insnsi);
+	};
 };
 
 struct sk_filter {

All fake flexible arrays in unions should be declared through the DECLARE_FLEX_ARRAY() helper. See:

--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -229,7 +229,7 @@ struct dp_audio_infoframe {
 union audio_infoframe {
        struct hdmi_audio_infoframe hdmi;
        struct dp_audio_infoframe dp;
-       u8 bytes[0];
+       DECLARE_FLEX_ARRAY(u8, bytes);
 };

Any fake flexible array alone in a struct should be declared through the DECLARE_FLEX_ARRAY() helper. See:

 union bmi_resp {
 	struct {
-		u8 payload[0];
+		DECLARE_FLEX_ARRAY(u8, payload);
 	} read_mem;
 	struct {
 		__le32 result;

For more details and examples:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3080ea5553cc909b000d1f1d964a9041962f2c5b
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa7845cfd53f3b1d3f60efa55db89805595bc045
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=47c662486cccf03e7062139d069b07ab0126ef59

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…elper Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declaration in union audio_infoframe with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union. Link: KSPP#193 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/Yw01A+TvF1FWQ588@work Signed-off-by: Takashi Iwai <tiwai@suse.de>

We now have a cleaner way to keep compatibility with user-space (a.k.a. not breaking it) when we need to keep in place a one-element array (for its use in user-space) together with a flexible-array member (for its use in kernel-space) without making it hard to read at the source level. This is through the use of the new __DECLARE_FLEX_ARRAY() helper macro. The size and memory layout of the structure is preserved after the changes. See below. Before changes: $ pahole -C ip_msfilter net/ipv4/igmp.o struct ip_msfilter { union { struct { __be32 imsf_multiaddr_aux; /* 0 4 */ __be32 imsf_interface_aux; /* 4 4 */ __u32 imsf_fmode_aux; /* 8 4 */ __u32 imsf_numsrc_aux; /* 12 4 */ __be32 imsf_slist[1]; /* 16 4 */ }; /* 0 20 */ struct { __be32 imsf_multiaddr; /* 0 4 */ __be32 imsf_interface; /* 4 4 */ __u32 imsf_fmode; /* 8 4 */ __u32 imsf_numsrc; /* 12 4 */ __be32 imsf_slist_flex[0]; /* 16 0 */ }; /* 0 16 */ }; /* 0 20 */ /* size: 20, cachelines: 1, members: 1 */ /* last cacheline: 20 bytes */ }; After changes: $ pahole -C ip_msfilter net/ipv4/igmp.o struct ip_msfilter { struct { __be32 imsf_multiaddr; /* 0 4 */ __be32 imsf_interface; /* 4 4 */ __u32 imsf_fmode; /* 8 4 */ __u32 imsf_numsrc; /* 12 4 */ union { __be32 imsf_slist[1]; /* 16 4 */ struct { struct { } __empty_imsf_slist_flex; /* 16 0 */ __be32 imsf_slist_flex[0]; /* 16 0 */ }; /* 16 0 */ }; /* 16 4 */ }; /* 0 20 */ /* size: 20, cachelines: 1, members: 1 */ /* last cacheline: 20 bytes */ }; In the past, we had to duplicate the whole original structure within a union, and update the names of all the members. Now, we just need to declare the flexible-array member to be used in kernel-space through the __DECLARE_FLEX_ARRAY() helper together with the one-element array, within a union. This makes the source code more clean and easier to read. Link: KSPP#193 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

We now have a cleaner way to keep compatibility with user-space (a.k.a. not breaking it) when we need to keep in place a one-element array (for its use in user-space) together with a flexible-array member (for its use in kernel-space) without making it hard to read at the source level. This is through the use of the new __DECLARE_FLEX_ARRAY() helper macro. The size and memory layout of the structure is preserved after the changes. See below. Before changes: $ pahole -C ip_msfilter net/ipv4/igmp.o struct ip_msfilter { union { struct { __be32 imsf_multiaddr_aux; /* 0 4 */ __be32 imsf_interface_aux; /* 4 4 */ __u32 imsf_fmode_aux; /* 8 4 */ __u32 imsf_numsrc_aux; /* 12 4 */ __be32 imsf_slist[1]; /* 16 4 */ }; /* 0 20 */ struct { __be32 imsf_multiaddr; /* 0 4 */ __be32 imsf_interface; /* 4 4 */ __u32 imsf_fmode; /* 8 4 */ __u32 imsf_numsrc; /* 12 4 */ __be32 imsf_slist_flex[0]; /* 16 0 */ }; /* 0 16 */ }; /* 0 20 */ /* size: 20, cachelines: 1, members: 1 */ /* last cacheline: 20 bytes */ }; After changes: $ pahole -C ip_msfilter net/ipv4/igmp.o struct ip_msfilter { __be32 imsf_multiaddr; /* 0 4 */ __be32 imsf_interface; /* 4 4 */ __u32 imsf_fmode; /* 8 4 */ __u32 imsf_numsrc; /* 12 4 */ union { __be32 imsf_slist[1]; /* 16 4 */ struct { struct { } __empty_imsf_slist_flex; /* 16 0 */ __be32 imsf_slist_flex[0]; /* 16 0 */ }; /* 16 0 */ }; /* 16 4 */ /* size: 20, cachelines: 1, members: 5 */ /* last cacheline: 20 bytes */ }; In the past, we had to duplicate the whole original structure within a union, and update the names of all the members. Now, we just need to declare the flexible-array member to be used in kernel-space through the __DECLARE_FLEX_ARRAY() helper together with the one-element array, within a union. This makes the source code more clean and easier to read. Link: KSPP#193 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. So, replace zero-length array declaration in struct fid with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union. Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declarations in a couple of structures and unions with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union and as only member in a structure. Also, this addresses multiple warnings reported when building with Clang-15 and -Wzero-length-array. Lastly, this will also help memcpy (in a coming hardening update) execute proper bounds-checking on variable length object i_symlink at fs/ocfs2/namei.c:1973: fs/ocfs2/namei.c: 1973 memcpy((char *) fe->id2.i_symlink, symname, l); Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declarations in a couple of structures and unions with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union and as only member in a structure. Also, this addresses multiple warnings reported when building with Clang-15 and -Wzero-length-array. Lastly, this will also help memcpy (in a coming hardening update) execute proper bounds-checking on variable length object i_symlink at fs/ocfs2/namei.c:1973: fs/ocfs2/namei.c: 1973 memcpy((char *) fe->id2.i_symlink, symname, l); Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Link: https://lkml.kernel.org/r/YxKY6O2hmdwNh8r8@work Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. So, replace zero-length array declaration with the new DECLARE_FLEX_ARRAY() helper macro in struct modsig. This helper allows for a flexible-array member in a union. Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. So, replace zero-length array declaration with the new DECLARE_FLEX_ARRAY() helper macro in struct ima_template_entry. This helper allows for a flexible-array member in a union. Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. So, replace zero-length array declaration with the new DECLARE_FLEX_ARRAY() helper macro in struct ima_rule_opt_list. This helper allows for a flexible-array member in a union. Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. So, replace zero-length array declarations with the new DECLARE_FLEX_ARRAY() helper macro in integrity.h. As follows: struct evm_ima_xattr_data, struct ima_digest_data, struct signature_v2_hdr, This helper allows for a flexible-array member in a union. Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declarations in a couple of structures and unions with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union and as only member in a structure. Also, this addresses multiple warnings reported when building with Clang-15 and -Wzero-length-array. Lastly, this will also help memcpy (in a coming hardening update) execute proper bounds-checking on variable length object i_symlink at fs/ocfs2/namei.c:1973: fs/ocfs2/namei.c: 1973 memcpy((char *) fe->id2.i_symlink, symname, l); Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Link: https://lkml.kernel.org/r/YxKY6O2hmdwNh8r8@work Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

…helper Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declaration in union es58x_urb_cmd with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union. Link: KSPP#193 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declaration in struct dev_pagemap with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union. Also, this addresses multiple warnings reported when building with Clang-15 and -Wzero-length-array. Link: KSPP#193 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. So, replace zero-length array declaration in struct fid with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union. Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declarations in a couple of structures and unions with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union and as only member in a structure. Also, this addresses multiple warnings reported when building with Clang-15 and -Wzero-length-array. Lastly, this will also help memcpy (in a coming hardening update) execute proper bounds-checking on variable length object i_symlink at fs/ocfs2/namei.c:1973: fs/ocfs2/namei.c: 1973 memcpy((char *) fe->id2.i_symlink, symname, l); Link: KSPP#21 Link: KSPP#193 Link: KSPP#197 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Link: https://lkml.kernel.org/r/YxKY6O2hmdwNh8r8@work Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Zero-length arrays as fake flexible arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in unions with flexible-array members. Address the following warning found with GCC-13 and -fstrict-flex-arrays=3 enabled: drivers/iio/accel/cros_ec_accel_legacy.c:66:46: warning: array subscript <unknown> is outside array bounds of ‘struct ec_response_motion_sensor_data[0]’ [-Warray-bounds=] This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: KSPP#21 Link: KSPP#193 Link: KSPP#262 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

…lper Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations in anonymous union with the new __DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members in unions. Link: KSPP/linux#193 Link: KSPP/linux#227 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays as fake flexible arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in unions with flexible-array members. Address the following warning found with GCC-13 and -fstrict-flex-arrays=3 enabled: drivers/iio/accel/cros_ec_accel_legacy.c:66:46: warning: array subscript <unknown> is outside array bounds of ‘struct ec_response_motion_sensor_data[0]’ [-Warray-bounds=] This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: KSPP/linux#21 Link: KSPP/linux#193 Link: KSPP/linux#262 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> Link: https://lore.kernel.org/r/ZAZUGBmSLc5wg7AK@work

Zero-length arrays as fake flexible arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in unions with flexible-array members. Address the following warning found with GCC-13 and -fstrict-flex-arrays=3 enabled: drivers/iio/accel/cros_ec_accel_legacy.c:66:46: warning: array subscript <unknown> is outside array bounds of ‘struct ec_response_motion_sensor_data[0]’ [-Warray-bounds=] This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: KSPP#21 Link: KSPP#193 Link: KSPP#262 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> Link: https://lore.kernel.org/r/ZAZUGBmSLc5wg7AK@work

…() helper Zero-length arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations alone in structs with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members alone in structs. Link: KSPP#193 Link: KSPP#288 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations alone in structs with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members alone in structs. Link: KSPP#193 Link: KSPP#285 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

…() helper Zero-length arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations alone in structs with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members alone in structs. Link: KSPP#193 Link: KSPP#287 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations alone in structs with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members alone in structs. Link: KSPP#193 Link: KSPP#285 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/ZGKGiBxP0zHo6XSK@work Signed-off-by: Jakub Kicinski <kuba@kernel.org>

…() helper Zero-length arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations alone in structs with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members alone in structs. Link: KSPP#193 Link: KSPP#287 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com> Link: https://lore.kernel.org/r/ZGKHByxujJoygK+l@work

…() helper Zero-length arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations alone in structs with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members alone in structs. Link: KSPP#193 Link: KSPP#288 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com> Link: https://lore.kernel.org/r/ZGKHM+MWFsuqzTjm@work

…mbers Zero-length and one-element arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in a union into flexible-array members. And replace a one-element array with a C99 flexible-array member. Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1009:89: warning: array subscript kk is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1007:94: warning: array subscript kk is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1310:94: warning: array subscript k is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1309:57: warning: array subscript k is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. This results in no differences in binary output. Link: KSPP#21 Link: KSPP#193 Link: KSPP#300 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

…mbers Zero-length and one-element arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in a union into flexible-array members. And replace a one-element array with a C99 flexible-array member. Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1009:89: warning: array subscript kk is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1007:94: warning: array subscript kk is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1310:94: warning: array subscript k is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1309:57: warning: array subscript k is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. This results in no differences in binary output. Link: KSPP#21 Link: KSPP#193 Link: KSPP#300 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

One-element arrays as fake flex arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace one-element array declaration in struct ct_sns_gpnft_rsp, which is ultimately being used inside a union: drivers/scsi/qla2xxx/qla_def.h: 3240 struct ct_sns_gpnft_pkt { 3241 union { 3242 struct ct_sns_req req; 3243 struct ct_sns_gpnft_rsp rsp; 3244 } p; 3245 }; Refactor the rest of the code, accordingly. This issue was found with the help of Coccinelle. Link: KSPP#245 Link: KSPP#193 Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

…lper One-element arrays as fake flex arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace one-element array declaration in struct ct_sns_gpnft_rsp, which is ultimately being used inside a union: drivers/scsi/qla2xxx/qla_def.h: 3240 struct ct_sns_gpnft_pkt { 3241 union { 3242 struct ct_sns_req req; 3243 struct ct_sns_gpnft_rsp rsp; 3244 } p; 3245 }; Refactor the rest of the code, accordingly. This issue was found with the help of Coccinelle. Link: KSPP#245 Link: KSPP#193 Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/ZH+/rZ1R1cBjIxjS@work Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

…mbers Zero-length and one-element arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in a union into flexible-array members. And replace a one-element array with a C99 flexible-array member. Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1009:89: warning: array subscript kk is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1007:94: warning: array subscript kk is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1310:94: warning: array subscript k is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1309:57: warning: array subscript k is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. This results in no differences in binary output. Link: KSPP/linux#21 Link: KSPP/linux#193 Link: KSPP/linux#300 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

…helper One-element arrays as fake flex arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace one-element array declaration in struct ct_sns_gpnft_rsp, which is ultimately being used inside a union: drivers/scsi/qla2xxx/qla_def.h: 3240 struct ct_sns_gpnft_pkt { 3241 union { 3242 struct ct_sns_req req; 3243 struct ct_sns_gpnft_rsp rsp; 3244 } p; 3245 }; Refactor the rest of the code, accordingly. This issue was found with the help of Coccinelle. Link: KSPP/linux#245 Link: KSPP/linux#193 Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/ZH+/rZ1R1cBjIxjS@work Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> [ commit 512a365368c7 upstream ]

…mbers Zero-length and one-element arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in a union into flexible-array members. And replace a one-element array with a C99 flexible-array member. Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1009:89: warning: array subscript kk is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1007:94: warning: array subscript kk is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1310:94: warning: array subscript k is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1309:57: warning: array subscript k is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. This results in no differences in binary output. Link: KSPP/linux#21 Link: KSPP/linux#193 Link: KSPP/linux#300 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

kees · 2024-02-06T16:43:44Z

All of these are done. Closing the issue.

JIRA: https://issues.redhat.com/browse/RHEL-27740 Tested: by me commit 06919d226d01132c03d851966d4df3870fa1b55a Author: Gustavo A. R. Silva <gustavoars@kernel.org> Date: Sat Sep 3 00:17:18 2022 +0100 mm/memremap: Replace zero-length array with DECLARE_FLEX_ARRAY() helper Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declaration in struct dev_pagemap with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union. Also, this addresses multiple warnings reported when building with Clang-15 and -Wzero-length-array. Link: KSPP/linux#193 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>

JIRA: https://issues.redhat.com/browse/RHEL-34673 commit b1cf7a5615157e958c2bdac9aa981676c07a10d9 Author: Gustavo A. R. Silva <gustavoars@kernel.org> Date: Mon May 15 13:22:48 2023 -0600 mlxfw: Replace zero-length array with DECLARE_FLEX_ARRAY() helper Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations alone in structs with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members alone in structs. Link: KSPP/linux#193 Link: KSPP/linux#285 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/ZGKGiBxP0zHo6XSK@work Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Ivan Vecera <ivecera@redhat.com>

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations alone in structs with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for flexible-array members alone in structs. Link: KSPP/linux#193 Link: KSPP/linux#285 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/ZGKGiBxP0zHo6XSK@work Signed-off-by: Jakub Kicinski <kuba@kernel.org> Orabug: 35622106 (cherry picked from commit b1cf7a5) cherry-pick-repo=kernel/git/torvalds/linux.git unmodified-from-upstream: b1cf7a5 Signed-off-by: Mikhael Goikhman <migo@nvidia.com> Signed-off-by: Qing Huang <qing.huang@oracle.com> Reviewed-by: Devesh Sharma <devesh.s.sharma@oracle.com> Signed-off-by: Brian Maly <brian.maly@oracle.com>

…mbers Zero-length and one-element arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in a union into flexible-array members. And replace a one-element array with a C99 flexible-array member. Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1009:89: warning: array subscript kk is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1007:94: warning: array subscript kk is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1310:94: warning: array subscript k is outside array bounds of ‘uint64_t[0]’ {aka ‘long long unsigned int[]’} [-Warray-bounds=] drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1309:57: warning: array subscript k is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds=] This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. This results in no differences in binary output. Link: KSPP/linux#21 Link: KSPP/linux#193 Link: KSPP/linux#300 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

GustavoARSilva self-assigned this Aug 29, 2022

GustavoARSilva added [Idiom] fake flexible array [Refactor] 0-element array Conversion away from zero-length array labels Sep 24, 2022

kees closed this as completed Feb 6, 2024

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Replace fake flexible-array declarations with the DECLARE_FLEX_ARRAY() helper macro #193

Replace fake flexible-array declarations with the DECLARE_FLEX_ARRAY() helper macro #193

GustavoARSilva commented Aug 29, 2022 •

edited by kees

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kees commented Feb 6, 2024

Replace fake flexible-array declarations with the DECLARE_FLEX_ARRAY() helper macro #193

Replace fake flexible-array declarations with the DECLARE_FLEX_ARRAY() helper macro #193

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GustavoARSilva commented Aug 29, 2022 • edited by kees Loading

kees commented Feb 6, 2024

GustavoARSilva commented Aug 29, 2022 •

edited by kees

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