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authorAndy Lutomirski <luto@amacapital.net>2015-01-04 10:36:19 -0800
committerIngo Molnar <mingo@kernel.org>2015-01-09 11:12:28 +0100
commit88a7c26af8dab2f2d69f5a6067eb670694ec38c0 (patch)
treee8a9d6c7512f7644a2a5a583b16f6fe4b29b16af /kernel
parent0f363b250b15af0f218bb2876d101fe5cd413f8b (diff)
downloadop-kernel-dev-88a7c26af8dab2f2d69f5a6067eb670694ec38c0.zip
op-kernel-dev-88a7c26af8dab2f2d69f5a6067eb670694ec38c0.tar.gz
perf: Move task_pt_regs sampling into arch code
On x86_64, at least, task_pt_regs may be only partially initialized in many contexts, so x86_64 should not use it without extra care from interrupt context, let alone NMI context. This will allow x86_64 to override the logic and will supply some scratch space to use to make a cleaner copy of user regs. Tested-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: chenggang.qcg@taobao.com Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jean Pihet <jean.pihet@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Salter <msalter@redhat.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/e431cd4c18c2e1c44c774f10758527fb2d1025c4.1420396372.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c19
1 files changed, 8 insertions, 11 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4c1ee7f..882f835 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4461,18 +4461,14 @@ perf_output_sample_regs(struct perf_output_handle *handle,
}
static void perf_sample_regs_user(struct perf_regs *regs_user,
- struct pt_regs *regs)
+ struct pt_regs *regs,
+ struct pt_regs *regs_user_copy)
{
- if (!user_mode(regs)) {
- if (current->mm)
- regs = task_pt_regs(current);
- else
- regs = NULL;
- }
-
- if (regs) {
- regs_user->abi = perf_reg_abi(current);
+ if (user_mode(regs)) {
+ regs_user->abi = perf_reg_abi(current);
regs_user->regs = regs;
+ } else if (current->mm) {
+ perf_get_regs_user(regs_user, regs, regs_user_copy);
} else {
regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
regs_user->regs = NULL;
@@ -4951,7 +4947,8 @@ void perf_prepare_sample(struct perf_event_header *header,
}
if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
- perf_sample_regs_user(&data->regs_user, regs);
+ perf_sample_regs_user(&data->regs_user, regs,
+ &data->regs_user_copy);
if (sample_type & PERF_SAMPLE_REGS_USER) {
/* regs dump ABI info */
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