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Patch "kbuild: disable clang's default use of -fmerge-all-constants" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kbuild: disable clang's default use of -fmerge-all-constants to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kbuild-disable-clang-s-default-use-of-fmerge-all-constants.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 87e0d4f0f37fb0c8c4aeeac46fff5e957738df79 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann <daniel(a)iogearbox.net> Date: Wed, 21 Mar 2018 01:18:24 +0100 Subject: kbuild: disable clang's default use of -fmerge-all-constants From: Daniel Borkmann <daniel(a)iogearbox.net> commit 87e0d4f0f37fb0c8c4aeeac46fff5e957738df79 upstream. Prasad reported that he has seen crashes in BPF subsystem with netd on Android with arm64 in the form of (note, the taint is unrelated): [ 4134.721483] Unable to handle kernel paging request at virtual address 800000001 [ 4134.820925] Mem abort info: [ 4134.901283] Exception class = DABT (current EL), IL = 32 bits [ 4135.016736] SET = 0, FnV = 0 [ 4135.119820] EA = 0, S1PTW = 0 [ 4135.201431] Data abort info: [ 4135.301388] ISV = 0, ISS = 0x00000021 [ 4135.359599] CM = 0, WnR = 0 [ 4135.470873] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffe39b946000 [ 4135.499757] [0000000800000001] *pgd=0000000000000000, *pud=0000000000000000 [ 4135.660725] Internal error: Oops: 96000021 [#1] PREEMPT SMP [ 4135.674610] Modules linked in: [ 4135.682883] CPU: 5 PID: 1260 Comm: netd Tainted: G S W 4.14.19+ #1 [ 4135.716188] task: ffffffe39f4aa380 task.stack: ffffff801d4e0000 [ 4135.731599] PC is at bpf_prog_add+0x20/0x68 [ 4135.741746] LR is at bpf_prog_inc+0x20/0x2c [ 4135.751788] pc : [<ffffff94ab7ad584>] lr : [<ffffff94ab7ad638>] pstate: 60400145 [ 4135.769062] sp : ffffff801d4e3ce0 [...] [ 4136.258315] Process netd (pid: 1260, stack limit = 0xffffff801d4e0000) [ 4136.273746] Call trace: [...] [ 4136.442494] 3ca0: ffffff94ab7ad584 0000000060400145 ffffffe3a01bf8f8 0000000000000006 [ 4136.460936] 3cc0: 0000008000000000 ffffff94ab844204 ffffff801d4e3cf0 ffffff94ab7ad584 [ 4136.479241] [<ffffff94ab7ad584>] bpf_prog_add+0x20/0x68 [ 4136.491767] [<ffffff94ab7ad638>] bpf_prog_inc+0x20/0x2c [ 4136.504536] [<ffffff94ab7b5d08>] bpf_obj_get_user+0x204/0x22c [ 4136.518746] [<ffffff94ab7ade68>] SyS_bpf+0x5a8/0x1a88 Android's netd was basically pinning the uid cookie BPF map in BPF fs (/sys/fs/bpf/traffic_cookie_uid_map) and later on retrieving it again resulting in above panic. Issue is that the map was wrongly identified as a prog! Above kernel was compiled with clang 4.0, and it turns out that clang decided to merge the bpf_prog_iops and bpf_map_iops into a single memory location, such that the two i_ops could then not be distinguished anymore. Reason for this miscompilation is that clang has the more aggressive -fmerge-all-constants enabled by default. In fact, clang source code has a comment about it in lib/AST/ExprConstant.cpp on why it is okay to do so: Pointers with different bases cannot represent the same object. (Note that clang defaults to -fmerge-all-constants, which can lead to inconsistent results for comparisons involving the address of a constant; this generally doesn't matter in practice.) The issue never appeared with gcc however, since gcc does not enable -fmerge-all-constants by default and even *explicitly* states in it's option description that using this flag results in non-conforming behavior, quote from man gcc: Languages like C or C++ require each variable, including multiple instances of the same variable in recursive calls, to have distinct locations, so using this option results in non-conforming behavior. There are also various clang bug reports open on that matter [1], where clang developers acknowledge the non-conforming behavior, and refer to disabling it with -fno-merge-all-constants. But even if this gets fixed in clang today, there are already users out there that triggered this. Thus, fix this issue by explicitly adding -fno-merge-all-constants to the kernel's Makefile to generically disable this optimization, since potentially other places in the kernel could subtly break as well. Note, there is also a flag called -fmerge-constants (not supported by clang), which is more conservative and only applies to strings and it's enabled in gcc's -O/-O2/-O3/-Os optimization levels. In gcc's code, the two flags -fmerge-{all-,}constants share the same variable internally, so when disabling it via -fno-merge-all-constants, then we really don't merge any const data (e.g. strings), and text size increases with gcc (14,927,214 -> 14,942,646 for vmlinux.o). $ gcc -fverbose-asm -O2 foo.c -S -o foo.S -> foo.S lists -fmerge-constants under options enabled $ gcc -fverbose-asm -O2 -fno-merge-all-constants foo.c -S -o foo.S -> foo.S doesn't list -fmerge-constants under options enabled $ gcc -fverbose-asm -O2 -fno-merge-all-constants -fmerge-constants foo.c -S -o foo.S -> foo.S lists -fmerge-constants under options enabled Thus, as a workaround we need to set both -fno-merge-all-constants *and* -fmerge-constants in the Makefile in order for text size to stay as is. [1] https://bugs.llvm.org/show_bug.cgi?id=18538 Reported-by: Prasad Sodagudi <psodagud(a)codeaurora.org> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Chenbo Feng <fengc(a)google.com> Cc: Richard Smith <richard-llvm(a)metafoo.co.uk> Cc: Chandler Carruth <chandlerc(a)gmail.com> Cc: linux-kernel(a)vger.kernel.org Tested-by: Prasad Sodagudi <psodagud(a)codeaurora.org> Acked-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- Makefile | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/Makefile +++ b/Makefile @@ -798,6 +798,15 @@ KBUILD_CFLAGS += $(call cc-disable-warni # disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow) +# clang sets -fmerge-all-constants by default as optimization, but this +# is non-conforming behavior for C and in fact breaks the kernel, so we +# need to disable it here generally. +KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants) + +# for gcc -fno-merge-all-constants disables everything, but it is fine +# to have actual conforming behavior enabled. +KBUILD_CFLAGS += $(call cc-option,-fmerge-constants) + # Make sure -fstack-check isn't enabled (like gentoo apparently did) KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,) Patches currently in stable-queue which might be from daniel(a)iogearbox.net are queue-4.15/trace-bpf-remove-helper-bpf_perf_prog_read_value-from-tracepoint-type-programs.patch queue-4.15/kbuild-disable-clang-s-default-use-of-fmerge-all-constants.patch queue-4.15/bpf-skip-unnecessary-capability-check.patch queue-4.15/bpf-x64-increase-number-of-passes.patch

7 years, 8 months

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Patch "bpf, x64: increase number of passes" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bpf, x64: increase number of passes to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bpf-x64-increase-number-of-passes.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 6007b080d2e2adb7af22bf29165f0594ea12b34c Mon Sep 17 00:00:00 2001 From: Daniel Borkmann <daniel(a)iogearbox.net> Date: Wed, 7 Mar 2018 22:10:01 +0100 Subject: bpf, x64: increase number of passes From: Daniel Borkmann <daniel(a)iogearbox.net> commit 6007b080d2e2adb7af22bf29165f0594ea12b34c upstream. In Cilium some of the main programs we run today are hitting 9 passes on x64's JIT compiler, and we've had cases already where we surpassed the limit where the JIT then punts the program to the interpreter instead, leading to insertion failures due to CONFIG_BPF_JIT_ALWAYS_ON or insertion failures due to the prog array owner being JITed but the program to insert not (both must have the same JITed/non-JITed property). One concrete case the program image shrunk from 12,767 bytes down to 10,288 bytes where the image converged after 16 steps. I've measured that this took 340us in the JIT until it converges on my i7-6600U. Thus, increase the original limit we had from day one where the JIT covered cBPF only back then before we run into the case (as similar with the complexity limit) where we trip over this and hit program rejections. Also add a cond_resched() into the compilation loop, the JIT process runs without any locks and may sleep anyway. Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Acked-by: Alexei Starovoitov <ast(a)kernel.org> Reviewed-by: Eric Dumazet <edumazet(a)google.com> Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/net/bpf_jit_comp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1156,7 +1156,7 @@ struct bpf_prog *bpf_int_jit_compile(str * may converge on the last pass. In such case do one more * pass to emit the final image */ - for (pass = 0; pass < 10 || image; pass++) { + for (pass = 0; pass < 20 || image; pass++) { proglen = do_jit(prog, addrs, image, oldproglen, &ctx); if (proglen <= 0) { image = NULL; @@ -1183,6 +1183,7 @@ struct bpf_prog *bpf_int_jit_compile(str } } oldproglen = proglen; + cond_resched(); } if (bpf_jit_enable > 1) Patches currently in stable-queue which might be from daniel(a)iogearbox.net are queue-4.15/trace-bpf-remove-helper-bpf_perf_prog_read_value-from-tracepoint-type-programs.patch queue-4.15/kbuild-disable-clang-s-default-use-of-fmerge-all-constants.patch queue-4.15/bpf-skip-unnecessary-capability-check.patch queue-4.15/bpf-x64-increase-number-of-passes.patch

7 years, 8 months

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Patch "bpf: skip unnecessary capability check" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bpf: skip unnecessary capability check to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bpf-skip-unnecessary-capability-check.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 0fa4fe85f4724fff89b09741c437cbee9cf8b008 Mon Sep 17 00:00:00 2001 From: Chenbo Feng <fengc(a)google.com> Date: Mon, 19 Mar 2018 17:57:27 -0700 Subject: bpf: skip unnecessary capability check From: Chenbo Feng <fengc(a)google.com> commit 0fa4fe85f4724fff89b09741c437cbee9cf8b008 upstream. The current check statement in BPF syscall will do a capability check for CAP_SYS_ADMIN before checking sysctl_unprivileged_bpf_disabled. This code path will trigger unnecessary security hooks on capability checking and cause false alarms on unprivileged process trying to get CAP_SYS_ADMIN access. This can be resolved by simply switch the order of the statement and CAP_SYS_ADMIN is not required anyway if unprivileged bpf syscall is allowed. Signed-off-by: Chenbo Feng <fengc(a)google.com> Acked-by: Lorenzo Colitti <lorenzo(a)google.com> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- kernel/bpf/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1687,7 +1687,7 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf union bpf_attr attr = {}; int err; - if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled) + if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN)) return -EPERM; err = check_uarg_tail_zero(uattr, sizeof(attr), size); Patches currently in stable-queue which might be from fengc(a)google.com are queue-4.15/kbuild-disable-clang-s-default-use-of-fmerge-all-constants.patch queue-4.15/bpf-skip-unnecessary-capability-check.patch

7 years, 8 months

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Patch "kbuild: disable clang's default use of -fmerge-all-constants" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kbuild: disable clang's default use of -fmerge-all-constants to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kbuild-disable-clang-s-default-use-of-fmerge-all-constants.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 87e0d4f0f37fb0c8c4aeeac46fff5e957738df79 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann <daniel(a)iogearbox.net> Date: Wed, 21 Mar 2018 01:18:24 +0100 Subject: kbuild: disable clang's default use of -fmerge-all-constants From: Daniel Borkmann <daniel(a)iogearbox.net> commit 87e0d4f0f37fb0c8c4aeeac46fff5e957738df79 upstream. Prasad reported that he has seen crashes in BPF subsystem with netd on Android with arm64 in the form of (note, the taint is unrelated): [ 4134.721483] Unable to handle kernel paging request at virtual address 800000001 [ 4134.820925] Mem abort info: [ 4134.901283] Exception class = DABT (current EL), IL = 32 bits [ 4135.016736] SET = 0, FnV = 0 [ 4135.119820] EA = 0, S1PTW = 0 [ 4135.201431] Data abort info: [ 4135.301388] ISV = 0, ISS = 0x00000021 [ 4135.359599] CM = 0, WnR = 0 [ 4135.470873] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffe39b946000 [ 4135.499757] [0000000800000001] *pgd=0000000000000000, *pud=0000000000000000 [ 4135.660725] Internal error: Oops: 96000021 [#1] PREEMPT SMP [ 4135.674610] Modules linked in: [ 4135.682883] CPU: 5 PID: 1260 Comm: netd Tainted: G S W 4.14.19+ #1 [ 4135.716188] task: ffffffe39f4aa380 task.stack: ffffff801d4e0000 [ 4135.731599] PC is at bpf_prog_add+0x20/0x68 [ 4135.741746] LR is at bpf_prog_inc+0x20/0x2c [ 4135.751788] pc : [<ffffff94ab7ad584>] lr : [<ffffff94ab7ad638>] pstate: 60400145 [ 4135.769062] sp : ffffff801d4e3ce0 [...] [ 4136.258315] Process netd (pid: 1260, stack limit = 0xffffff801d4e0000) [ 4136.273746] Call trace: [...] [ 4136.442494] 3ca0: ffffff94ab7ad584 0000000060400145 ffffffe3a01bf8f8 0000000000000006 [ 4136.460936] 3cc0: 0000008000000000 ffffff94ab844204 ffffff801d4e3cf0 ffffff94ab7ad584 [ 4136.479241] [<ffffff94ab7ad584>] bpf_prog_add+0x20/0x68 [ 4136.491767] [<ffffff94ab7ad638>] bpf_prog_inc+0x20/0x2c [ 4136.504536] [<ffffff94ab7b5d08>] bpf_obj_get_user+0x204/0x22c [ 4136.518746] [<ffffff94ab7ade68>] SyS_bpf+0x5a8/0x1a88 Android's netd was basically pinning the uid cookie BPF map in BPF fs (/sys/fs/bpf/traffic_cookie_uid_map) and later on retrieving it again resulting in above panic. Issue is that the map was wrongly identified as a prog! Above kernel was compiled with clang 4.0, and it turns out that clang decided to merge the bpf_prog_iops and bpf_map_iops into a single memory location, such that the two i_ops could then not be distinguished anymore. Reason for this miscompilation is that clang has the more aggressive -fmerge-all-constants enabled by default. In fact, clang source code has a comment about it in lib/AST/ExprConstant.cpp on why it is okay to do so: Pointers with different bases cannot represent the same object. (Note that clang defaults to -fmerge-all-constants, which can lead to inconsistent results for comparisons involving the address of a constant; this generally doesn't matter in practice.) The issue never appeared with gcc however, since gcc does not enable -fmerge-all-constants by default and even *explicitly* states in it's option description that using this flag results in non-conforming behavior, quote from man gcc: Languages like C or C++ require each variable, including multiple instances of the same variable in recursive calls, to have distinct locations, so using this option results in non-conforming behavior. There are also various clang bug reports open on that matter [1], where clang developers acknowledge the non-conforming behavior, and refer to disabling it with -fno-merge-all-constants. But even if this gets fixed in clang today, there are already users out there that triggered this. Thus, fix this issue by explicitly adding -fno-merge-all-constants to the kernel's Makefile to generically disable this optimization, since potentially other places in the kernel could subtly break as well. Note, there is also a flag called -fmerge-constants (not supported by clang), which is more conservative and only applies to strings and it's enabled in gcc's -O/-O2/-O3/-Os optimization levels. In gcc's code, the two flags -fmerge-{all-,}constants share the same variable internally, so when disabling it via -fno-merge-all-constants, then we really don't merge any const data (e.g. strings), and text size increases with gcc (14,927,214 -> 14,942,646 for vmlinux.o). $ gcc -fverbose-asm -O2 foo.c -S -o foo.S -> foo.S lists -fmerge-constants under options enabled $ gcc -fverbose-asm -O2 -fno-merge-all-constants foo.c -S -o foo.S -> foo.S doesn't list -fmerge-constants under options enabled $ gcc -fverbose-asm -O2 -fno-merge-all-constants -fmerge-constants foo.c -S -o foo.S -> foo.S lists -fmerge-constants under options enabled Thus, as a workaround we need to set both -fno-merge-all-constants *and* -fmerge-constants in the Makefile in order for text size to stay as is. [1] https://bugs.llvm.org/show_bug.cgi?id=18538 Reported-by: Prasad Sodagudi <psodagud(a)codeaurora.org> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Chenbo Feng <fengc(a)google.com> Cc: Richard Smith <richard-llvm(a)metafoo.co.uk> Cc: Chandler Carruth <chandlerc(a)gmail.com> Cc: linux-kernel(a)vger.kernel.org Tested-by: Prasad Sodagudi <psodagud(a)codeaurora.org> Acked-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- Makefile | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/Makefile +++ b/Makefile @@ -805,6 +805,15 @@ KBUILD_CFLAGS += $(call cc-disable-warni # disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow) +# clang sets -fmerge-all-constants by default as optimization, but this +# is non-conforming behavior for C and in fact breaks the kernel, so we +# need to disable it here generally. +KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants) + +# for gcc -fno-merge-all-constants disables everything, but it is fine +# to have actual conforming behavior enabled. +KBUILD_CFLAGS += $(call cc-option,-fmerge-constants) + # Make sure -fstack-check isn't enabled (like gentoo apparently did) KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,) Patches currently in stable-queue which might be from daniel(a)iogearbox.net are queue-4.14/kbuild-disable-clang-s-default-use-of-fmerge-all-constants.patch queue-4.14/bpf-skip-unnecessary-capability-check.patch queue-4.14/bpf-x64-increase-number-of-passes.patch

7 years, 8 months

1
0
0 0

Patch "bpf, x64: increase number of passes" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bpf, x64: increase number of passes to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bpf-x64-increase-number-of-passes.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 6007b080d2e2adb7af22bf29165f0594ea12b34c Mon Sep 17 00:00:00 2001 From: Daniel Borkmann <daniel(a)iogearbox.net> Date: Wed, 7 Mar 2018 22:10:01 +0100 Subject: bpf, x64: increase number of passes From: Daniel Borkmann <daniel(a)iogearbox.net> commit 6007b080d2e2adb7af22bf29165f0594ea12b34c upstream. In Cilium some of the main programs we run today are hitting 9 passes on x64's JIT compiler, and we've had cases already where we surpassed the limit where the JIT then punts the program to the interpreter instead, leading to insertion failures due to CONFIG_BPF_JIT_ALWAYS_ON or insertion failures due to the prog array owner being JITed but the program to insert not (both must have the same JITed/non-JITed property). One concrete case the program image shrunk from 12,767 bytes down to 10,288 bytes where the image converged after 16 steps. I've measured that this took 340us in the JIT until it converges on my i7-6600U. Thus, increase the original limit we had from day one where the JIT covered cBPF only back then before we run into the case (as similar with the complexity limit) where we trip over this and hit program rejections. Also add a cond_resched() into the compilation loop, the JIT process runs without any locks and may sleep anyway. Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Acked-by: Alexei Starovoitov <ast(a)kernel.org> Reviewed-by: Eric Dumazet <edumazet(a)google.com> Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/net/bpf_jit_comp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1156,7 +1156,7 @@ struct bpf_prog *bpf_int_jit_compile(str * may converge on the last pass. In such case do one more * pass to emit the final image */ - for (pass = 0; pass < 10 || image; pass++) { + for (pass = 0; pass < 20 || image; pass++) { proglen = do_jit(prog, addrs, image, oldproglen, &ctx); if (proglen <= 0) { image = NULL; @@ -1183,6 +1183,7 @@ struct bpf_prog *bpf_int_jit_compile(str } } oldproglen = proglen; + cond_resched(); } if (bpf_jit_enable > 1) Patches currently in stable-queue which might be from daniel(a)iogearbox.net are queue-4.14/kbuild-disable-clang-s-default-use-of-fmerge-all-constants.patch queue-4.14/bpf-skip-unnecessary-capability-check.patch queue-4.14/bpf-x64-increase-number-of-passes.patch

7 years, 8 months

1
0
0 0

Patch "bpf: skip unnecessary capability check" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bpf: skip unnecessary capability check to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bpf-skip-unnecessary-capability-check.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 0fa4fe85f4724fff89b09741c437cbee9cf8b008 Mon Sep 17 00:00:00 2001 From: Chenbo Feng <fengc(a)google.com> Date: Mon, 19 Mar 2018 17:57:27 -0700 Subject: bpf: skip unnecessary capability check From: Chenbo Feng <fengc(a)google.com> commit 0fa4fe85f4724fff89b09741c437cbee9cf8b008 upstream. The current check statement in BPF syscall will do a capability check for CAP_SYS_ADMIN before checking sysctl_unprivileged_bpf_disabled. This code path will trigger unnecessary security hooks on capability checking and cause false alarms on unprivileged process trying to get CAP_SYS_ADMIN access. This can be resolved by simply switch the order of the statement and CAP_SYS_ADMIN is not required anyway if unprivileged bpf syscall is allowed. Signed-off-by: Chenbo Feng <fengc(a)google.com> Acked-by: Lorenzo Colitti <lorenzo(a)google.com> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- kernel/bpf/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1455,7 +1455,7 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf union bpf_attr attr = {}; int err; - if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled) + if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN)) return -EPERM; err = check_uarg_tail_zero(uattr, sizeof(attr), size); Patches currently in stable-queue which might be from fengc(a)google.com are queue-4.14/kbuild-disable-clang-s-default-use-of-fmerge-all-constants.patch queue-4.14/bpf-skip-unnecessary-capability-check.patch

7 years, 8 months

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[PATCH] tpm: allow TCPA log area to be empty

by Jarkko Sakkinen

TCPA log are can be empty when the TPM is disabled. This commit changes the behavior of tpm_read_log_acpi() to return successfully in this case. Cc: stable(a)vger.kernel.org Fixes: 55a82ab3181b ("[PATCH] tpm: add bios measurement log") Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen(a)linux.intel.com> --- drivers/char/tpm/tpm_eventlog_acpi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_eventlog_acpi.c b/drivers/char/tpm/tpm_eventlog_acpi.c index 66f19e93c216..f5f66dcd6f30 100644 --- a/drivers/char/tpm/tpm_eventlog_acpi.c +++ b/drivers/char/tpm/tpm_eventlog_acpi.c @@ -84,8 +84,8 @@ int tpm_read_log_acpi(struct tpm_chip *chip) break; } if (!len) { - dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__); - return -EIO; + dev_info(&chip->dev, "TCPA log area is empty\n"); + return 0; } /* malloc EventLog space */ -- 2.15.1

7 years, 8 months

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BPF stable patches

by Daniel Borkmann

Hi Greg, if you have a chance, please queue the following BPF patches for -stable: - up to 4.15.y: f005afede992 ("trace/bpf: remove helper bpf_perf_prog_read_value from tracepoint type programs") - up to 4.4.y: 87e0d4f0f37f ("kbuild: disable clang's default use of -fmerge-all-constants") 0fa4fe85f472 ("bpf: skip unnecessary capability check") 6007b080d2e2 ("bpf, x64: increase number of passes") Thanks, Daniel

7 years, 8 months

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Patch "x86/pkeys/selftests: Rename 'si_pkey' to 'siginfo_pkey'" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/pkeys/selftests: Rename 'si_pkey' to 'siginfo_pkey' to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: x86-pkeys-selftests-rename-si_pkey-to-siginfo_pkey.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 91c49c2deb96ffc3c461eaae70219d89224076b7 Mon Sep 17 00:00:00 2001 From: Dave Hansen <dave.hansen(a)linux.intel.com> Date: Fri, 10 Nov 2017 16:12:31 -0800 Subject: x86/pkeys/selftests: Rename 'si_pkey' to 'siginfo_pkey' From: Dave Hansen <dave.hansen(a)linux.intel.com> commit 91c49c2deb96ffc3c461eaae70219d89224076b7 upstream. 'si_pkey' is now #defined to be the name of the new siginfo field that protection keys uses. Rename it not to conflict. Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Acked-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Link: http://lkml.kernel.org/r/20171111001231.DFFC8285@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- tools/testing/selftests/x86/protection_keys.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/tools/testing/selftests/x86/protection_keys.c +++ b/tools/testing/selftests/x86/protection_keys.c @@ -249,7 +249,7 @@ void signal_handler(int signum, siginfo_ unsigned long ip; char *fpregs; u32 *pkru_ptr; - u64 si_pkey; + u64 siginfo_pkey; u32 *si_pkey_ptr; int pkru_offset; fpregset_t fpregset; @@ -291,9 +291,9 @@ void signal_handler(int signum, siginfo_ si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset); dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr); dump_mem(si_pkey_ptr - 8, 24); - si_pkey = *si_pkey_ptr; - pkey_assert(si_pkey < NR_PKEYS); - last_si_pkey = si_pkey; + siginfo_pkey = *si_pkey_ptr; + pkey_assert(siginfo_pkey < NR_PKEYS); + last_si_pkey = siginfo_pkey; if ((si->si_code == SEGV_MAPERR) || (si->si_code == SEGV_ACCERR) || @@ -305,7 +305,7 @@ void signal_handler(int signum, siginfo_ dprintf1("signal pkru from xsave: %08x\n", *pkru_ptr); /* need __rdpkru() version so we do not do shadow_pkru checking */ dprintf1("signal pkru from pkru: %08x\n", __rdpkru()); - dprintf1("si_pkey from siginfo: %jx\n", si_pkey); + dprintf1("pkey from siginfo: %jx\n", siginfo_pkey); *(u64 *)pkru_ptr = 0x00000000; dprintf1("WARNING: set PRKU=0 to allow faulting instruction to continue\n"); pkru_faults++; Patches currently in stable-queue which might be from dave.hansen(a)linux.intel.com are queue-4.9/x86-pkeys-selftests-rename-si_pkey-to-siginfo_pkey.patch queue-4.9/signal-testing-don-t-look-for-__si_fault-in-userspace.patch queue-4.9/selftests-x86-protection_keys-fix-wrong-offset-in-siginfo.patch

7 years, 8 months

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Patch "signal/testing: Don't look for __SI_FAULT in userspace" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled signal/testing: Don't look for __SI_FAULT in userspace to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: signal-testing-don-t-look-for-__si_fault-in-userspace.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From d12fe87e62d773e81e0cb3a123c5a480a10d7d91 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" <ebiederm(a)xmission.com> Date: Mon, 26 Jun 2017 16:36:57 -0500 Subject: signal/testing: Don't look for __SI_FAULT in userspace From: Eric W. Biederman <ebiederm(a)xmission.com> commit d12fe87e62d773e81e0cb3a123c5a480a10d7d91 upstream. Fix the debug print statements in these tests where they reference si_codes and in particular __SI_FAULT. __SI_FAULT is a kernel internal value and should never be seen by userspace. While I am in there also fix si_code_str. si_codes are an enumeration there are not a bitmap so == and not & is the apropriate operation to test for an si_code. Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Fixes: 5f23f6d082a9 ("x86/pkeys: Add self-tests") Fixes: e754aedc26ef ("x86/mpx, selftests: Add MPX self test") Signed-off-by: "Eric W. Biederman" <ebiederm(a)xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- tools/testing/selftests/x86/mpx-mini-test.c | 3 +-- tools/testing/selftests/x86/protection_keys.c | 13 ++++++------- 2 files changed, 7 insertions(+), 9 deletions(-) --- a/tools/testing/selftests/x86/mpx-mini-test.c +++ b/tools/testing/selftests/x86/mpx-mini-test.c @@ -419,8 +419,7 @@ void handler(int signum, siginfo_t *si, br_count++; dprintf1("#BR 0x%jx (total seen: %d)\n", status, br_count); -#define __SI_FAULT (3 << 16) -#define SEGV_BNDERR (__SI_FAULT|3) /* failed address bound checks */ +#define SEGV_BNDERR 3 /* failed address bound checks */ dprintf2("Saw a #BR! status 0x%jx at %016lx br_reason: %jx\n", status, ip, br_reason); --- a/tools/testing/selftests/x86/protection_keys.c +++ b/tools/testing/selftests/x86/protection_keys.c @@ -224,19 +224,18 @@ void dump_mem(void *dumpme, int len_byte } } -#define __SI_FAULT (3 << 16) -#define SEGV_BNDERR (__SI_FAULT|3) /* failed address bound checks */ -#define SEGV_PKUERR (__SI_FAULT|4) +#define SEGV_BNDERR 3 /* failed address bound checks */ +#define SEGV_PKUERR 4 static char *si_code_str(int si_code) { - if (si_code & SEGV_MAPERR) + if (si_code == SEGV_MAPERR) return "SEGV_MAPERR"; - if (si_code & SEGV_ACCERR) + if (si_code == SEGV_ACCERR) return "SEGV_ACCERR"; - if (si_code & SEGV_BNDERR) + if (si_code == SEGV_BNDERR) return "SEGV_BNDERR"; - if (si_code & SEGV_PKUERR) + if (si_code == SEGV_PKUERR) return "SEGV_PKUERR"; return "UNKNOWN"; } Patches currently in stable-queue which might be from ebiederm(a)xmission.com are queue-4.9/x86-boot-64-verify-alignment-of-the-load-segment.patch queue-4.9/signal-testing-don-t-look-for-__si_fault-in-userspace.patch queue-4.9/x86-build-64-force-the-linker-to-use-2mb-page-size.patch

7 years, 8 months

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