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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-03 16:13:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-03 16:13:28 -0700
commit1a4a2bc460721bc8f91e4c1294d39b38e5af132f (patch)
treefe646d05f6e17f05601e0a32cc796bec718ab6e7 /arch/x86/events/core.c
parent110a9e42b68719f584879c5c5c727bbae90d15f9 (diff)
parent1ef55be16ed69538f89e0a6508be5e62fdc9851c (diff)
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull low-level x86 updates from Ingo Molnar: "In this cycle this topic tree has become one of those 'super topics' that accumulated a lot of changes: - Add CONFIG_VMAP_STACK=y support to the core kernel and enable it on x86 - preceded by an array of changes. v4.8 saw preparatory changes in this area already - this is the rest of the work. Includes the thread stack caching performance optimization. (Andy Lutomirski) - switch_to() cleanups and all around enhancements. (Brian Gerst) - A large number of dumpstack infrastructure enhancements and an unwinder abstraction. The secret long term plan is safe(r) live patching plus maybe another attempt at debuginfo based unwinding - but all these current bits are standalone enhancements in a frame pointer based debug environment as well. (Josh Poimboeuf) - More __ro_after_init and const annotations. (Kees Cook) - Enable KASLR for the vmemmap memory region. (Thomas Garnier)" [ The virtually mapped stack changes are pretty fundamental, and not x86-specific per se, even if they are only used on x86 right now. ] * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) x86/asm: Get rid of __read_cr4_safe() thread_info: Use unsigned long for flags x86/alternatives: Add stack frame dependency to alternative_call_2() x86/dumpstack: Fix show_stack() task pointer regression x86/dumpstack: Remove dump_trace() and related callbacks x86/dumpstack: Convert show_trace_log_lvl() to use the new unwinder oprofile/x86: Convert x86_backtrace() to use the new unwinder x86/stacktrace: Convert save_stack_trace_*() to use the new unwinder perf/x86: Convert perf_callchain_kernel() to use the new unwinder x86/unwind: Add new unwind interface and implementations x86/dumpstack: Remove NULL task pointer convention fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK lib/syscall: Pin the task stack in collect_syscall() x86/process: Pin the target stack in get_wchan() x86/dumpstack: Pin the target stack when dumping it kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function sched/core: Add try_get_task_stack() and put_task_stack() x86/entry/64: Fix a minor comment rebase error iommu/amd: Don't put completion-wait semaphore on stack ...
Diffstat (limited to 'arch/x86/events/core.c')
-rw-r--r--arch/x86/events/core.c36
1 files changed, 12 insertions, 24 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 18a1acf86c90..d31735f37ed7 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -37,6 +37,7 @@
#include <asm/timer.h>
#include <asm/desc.h>
#include <asm/ldt.h>
+#include <asm/unwind.h>
#include "perf_event.h"
@@ -2267,39 +2268,26 @@ void arch_perf_update_userpage(struct perf_event *event,
cyc2ns_read_end(data);
}
-/*
- * callchain support
- */
-
-static int backtrace_stack(void *data, char *name)
-{
- return 0;
-}
-
-static int backtrace_address(void *data, unsigned long addr, int reliable)
-{
- struct perf_callchain_entry_ctx *entry = data;
-
- return perf_callchain_store(entry, addr);
-}
-
-static const struct stacktrace_ops backtrace_ops = {
- .stack = backtrace_stack,
- .address = backtrace_address,
- .walk_stack = print_context_stack_bp,
-};
-
void
perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
+ struct unwind_state state;
+ unsigned long addr;
+
if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
/* TODO: We don't support guest os callchain now */
return;
}
- perf_callchain_store(entry, regs->ip);
+ if (perf_callchain_store(entry, regs->ip))
+ return;
- dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry);
+ for (unwind_start(&state, current, regs, NULL); !unwind_done(&state);
+ unwind_next_frame(&state)) {
+ addr = unwind_get_return_address(&state);
+ if (!addr || perf_callchain_store(entry, addr))
+ return;
+ }
}
static inline int