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authorPeter Zijlstra <peterz@infradead.org>2020-10-30 12:14:21 +0100
committerPeter Zijlstra <peterz@infradead.org>2020-11-09 18:12:34 +0100
commit76a4efa80900fc40e0fdf243b42aec9fb8c35d24 (patch)
treee71668f6517452f1f7c13aac88a9dabab3f47b94 /arch/x86
parent09da9c81253dd8e43e0d2d7cea02de6f9f19499d (diff)
downloadlinux-76a4efa80900fc40e0fdf243b42aec9fb8c35d24.tar.bz2
perf/arch: Remove perf_sample_data::regs_user_copy
struct perf_sample_data lives on-stack, we should be careful about it's size. Furthermore, the pt_regs copy in there is only because x86_64 is a trainwreck, solve it differently. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Steven Rostedt <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/perf_regs.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c
index bb7e1132290b..f9e5352b3bef 100644
--- a/arch/x86/kernel/perf_regs.c
+++ b/arch/x86/kernel/perf_regs.c
@@ -101,8 +101,7 @@ u64 perf_reg_abi(struct task_struct *task)
}
void perf_get_regs_user(struct perf_regs *regs_user,
- struct pt_regs *regs,
- struct pt_regs *regs_user_copy)
+ struct pt_regs *regs)
{
regs_user->regs = task_pt_regs(current);
regs_user->abi = perf_reg_abi(current);
@@ -129,12 +128,20 @@ u64 perf_reg_abi(struct task_struct *task)
return PERF_SAMPLE_REGS_ABI_64;
}
+static DEFINE_PER_CPU(struct pt_regs, nmi_user_regs);
+
void perf_get_regs_user(struct perf_regs *regs_user,
- struct pt_regs *regs,
- struct pt_regs *regs_user_copy)
+ struct pt_regs *regs)
{
+ struct pt_regs *regs_user_copy = this_cpu_ptr(&nmi_user_regs);
struct pt_regs *user_regs = task_pt_regs(current);
+ if (!in_nmi()) {
+ regs_user->regs = user_regs;
+ regs_user->abi = perf_reg_abi(current);
+ return;
+ }
+
/*
* If we're in an NMI that interrupted task_pt_regs setup, then
* we can't sample user regs at all. This check isn't really