From mboxrd@z Thu Jan 1 00:00:00 1970 From: alex.popov@linux.com (Alexander Popov) Date: Sun, 11 Dec 2016 03:50:56 +0300 Subject: [PATCH 2/2] kcov: make kcov work properly with KASLR enabled In-Reply-To: <1481417456-28826-1-git-send-email-alex.popov@linux.com> References: <1481417456-28826-1-git-send-email-alex.popov@linux.com> Message-ID: <1481417456-28826-3-git-send-email-alex.popov@linux.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Subtract KASLR offset from the kernel addresses reported by kcov. Tested on x86_64 and AArch64 (Hikey LeMaker). Signed-off-by: Alexander Popov --- kernel/kcov.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/kernel/kcov.c b/kernel/kcov.c index 3cbb0c8..f8f3f4c 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -14,6 +14,7 @@ #include #include #include +#include /* * kcov descriptor (one per opened debugfs file). @@ -68,6 +69,11 @@ 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 @@ -81,7 +87,7 @@ 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); } } -- 2.7.4