diff options
| author | Alexander Popov <alex.popov@linux.com> | 2016-12-19 16:23:09 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-20 09:48:47 -0800 |
| commit | 4983f0ab7ffaad1e534b21975367429736475205 (patch) | |
| tree | 5b67abd27fa361e1441cade25051632ecd10316f /kernel/kcov.c | |
| parent | 7ede8665f27cde7da69e8b2fbeaa1ed0664879c5 (diff) | |
| download | lwn-4983f0ab7ffaad1e534b21975367429736475205.tar.gz lwn-4983f0ab7ffaad1e534b21975367429736475205.zip | |
kcov: make kcov work properly with KASLR enabled
Subtract KASLR offset from the kernel addresses reported by kcov.
Tested on x86_64 and AArch64 (Hikey LeMaker).
Link: http://lkml.kernel.org/r/1481417456-28826-3-git-send-email-alex.popov@linux.com
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Jon Masters <jcm@redhat.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nicolai Stange <nicstange@gmail.com>
Cc: James Morse <james.morse@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/kcov.c')
| -rw-r--r-- | kernel/kcov.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/kcov.c b/kernel/kcov.c index cc2fa35ca480..85e5546cd791 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -19,6 +19,7 @@ #include <linux/debugfs.h> #include <linux/uaccess.h> #include <linux/kcov.h> +#include <asm/setup.h> /* * kcov descriptor (one per opened debugfs file). @@ -73,6 +74,11 @@ void notrace __sanitizer_cov_trace_pc(void) if (mode == KCOV_MODE_TRACE) { unsigned long *area; unsigned long pos; + unsigned long ip = _RET_IP_; + +#ifdef CONFIG_RANDOMIZE_BASE + ip -= kaslr_offset(); +#endif /* * There is some code that runs in interrupts but for which @@ -86,7 +92,7 @@ void notrace __sanitizer_cov_trace_pc(void) /* The first word is number of subsequent PCs. */ pos = READ_ONCE(area[0]) + 1; if (likely(pos < t->kcov_size)) { - area[pos] = _RET_IP_; + area[pos] = ip; WRITE_ONCE(area[0], pos); } } |