[RFC,08/10] perf/x86: Use user_unwind interface
Commit Message
Simplify __perf_callchain_user() and prepare for sframe user space
unwinding by switching to the generic user unwind interface.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
arch/x86/events/core.c | 20 +++++---------------
1 file changed, 5 insertions(+), 15 deletions(-)
@@ -29,6 +29,7 @@
#include <linux/device.h>
#include <linux/nospec.h>
#include <linux/static_call.h>
+#include <linux/user_unwind.h>
#include <asm/apic.h>
#include <asm/stacktrace.h>
@@ -2856,8 +2857,7 @@ static inline int __perf_callchain_user32(struct pt_regs *regs,
void __perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs, bool atomic)
{
- struct stack_frame frame;
- const struct stack_frame __user *fp;
+ struct user_unwind_state state;
if (perf_guest_state()) {
/* TODO: We don't support guest os callchain now */
@@ -2870,8 +2870,6 @@ void __perf_callchain_user(struct perf_callchain_entry_ctx *entry,
if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
return;
- fp = (void __user *)regs->bp;
-
perf_callchain_store(entry, regs->ip);
if (atomic && !nmi_uaccess_okay())
@@ -2883,17 +2881,9 @@ void __perf_callchain_user(struct perf_callchain_entry_ctx *entry,
if (__perf_callchain_user32(regs, entry))
goto done;
- while (entry->nr < entry->max_stack) {
- if (!valid_user_frame(fp, sizeof(frame)))
- break;
-
- if (__get_user(frame.next_frame, &fp->next_frame))
- break;
- if (__get_user(frame.return_address, &fp->return_address))
- break;
-
- perf_callchain_store(entry, frame.return_address);
- fp = (void __user *)frame.next_frame;
+ for_each_user_frame(state, USER_UNWIND_TYPE_AUTO) {
+ if (perf_callchain_store(entry, state.ip))
+ goto done;
}
done:
if (atomic)