[PATCH 08/12] perf core: Pass max stack as a perf_callchain_entry context

From: Arnaldo Carvalho de Melo
Date: Mon May 16 2016 - 22:46:40 EST

From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

This makes perf_callchain_{user,kernel}() receive the max stack
as context for the perf_callchain_entry, instead of accessing
the global sysctl_perf_event_max_stack.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Milian Wolff <milian.wolff@xxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
arch/arc/kernel/perf_event.c | 6 +++---
arch/arm/kernel/perf_callchain.c | 10 +++++-----
arch/arm64/kernel/perf_callchain.c | 14 +++++++-------
arch/metag/kernel/perf_callchain.c | 10 +++++-----
arch/mips/kernel/perf_event.c | 12 ++++++------
arch/powerpc/perf/callchain.c | 14 +++++++-------
arch/s390/kernel/perf_event.c | 4 ++--
arch/sh/kernel/perf_callchain.c | 4 ++--
arch/sparc/kernel/perf_event.c | 14 +++++++-------
arch/tile/kernel/perf_event.c | 6 +++---
arch/x86/events/core.c | 14 +++++++-------
arch/xtensa/kernel/perf_event.c | 10 +++++-----
include/linux/perf_event.h | 16 +++++++++++-----
kernel/bpf/stackmap.c | 3 ++-
kernel/events/callchain.c | 20 ++++++++++++--------
15 files changed, 84 insertions(+), 73 deletions(-)

diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c
index 8b134cfe5e1f..6fd48021324b 100644
--- a/arch/arc/kernel/perf_event.c
+++ b/arch/arc/kernel/perf_event.c
@@ -48,7 +48,7 @@ struct arc_callchain_trace {
static int callchain_trace(unsigned int addr, void *data)
{
struct arc_callchain_trace *ctrl = data;
- struct perf_callchain_entry *entry = ctrl->perf_stuff;
+ struct perf_callchain_entry_ctx *entry = ctrl->perf_stuff;
perf_callchain_store(entry, addr);

if (ctrl->depth++ < 3)
@@ -58,7 +58,7 @@ static int callchain_trace(unsigned int addr, void *data)
}

void
-perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
struct arc_callchain_trace ctrl = {
.depth = 0,
@@ -69,7 +69,7 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
}

void
-perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
/*
* User stack can't be unwound trivially with kernel dwarf unwinder
diff --git a/arch/arm/kernel/perf_callchain.c b/arch/arm/kernel/perf_callchain.c
index 27563befa8a2..bc552e813e7b 100644
--- a/arch/arm/kernel/perf_callchain.c
+++ b/arch/arm/kernel/perf_callchain.c
@@ -31,7 +31,7 @@ struct frame_tail {
*/
static struct frame_tail __user *
user_backtrace(struct frame_tail __user *tail,
- struct perf_callchain_entry *entry)
+ struct perf_callchain_entry_ctx *entry)
{
struct frame_tail buftail;
unsigned long err;
@@ -59,7 +59,7 @@ user_backtrace(struct frame_tail __user *tail,
}

void
-perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
struct frame_tail __user *tail;

@@ -75,7 +75,7 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)

tail = (struct frame_tail __user *)regs->ARM_fp - 1;

- while ((entry->nr < sysctl_perf_event_max_stack) &&
+ while ((entry->entry->nr < entry->max_stack) &&
tail && !((unsigned long)tail & 0x3))
tail = user_backtrace(tail, entry);
}
@@ -89,13 +89,13 @@ static int
callchain_trace(struct stackframe *fr,
void *data)
{
- struct perf_callchain_entry *entry = data;
+ struct perf_callchain_entry_ctx *entry = data;
perf_callchain_store(entry, fr->pc);
return 0;
}

void
-perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
struct stackframe fr;

diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index 32c3c6e70119..0d60150057cf 100644
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -31,7 +31,7 @@ struct frame_tail {
*/
static struct frame_tail __user *
user_backtrace(struct frame_tail __user *tail,
- struct perf_callchain_entry *entry)
+ struct perf_callchain_entry_ctx *entry)
{
struct frame_tail buftail;
unsigned long err;
@@ -76,7 +76,7 @@ struct compat_frame_tail {

static struct compat_frame_tail __user *
compat_user_backtrace(struct compat_frame_tail __user *tail,
- struct perf_callchain_entry *entry)
+ struct perf_callchain_entry_ctx *entry)
{
struct compat_frame_tail buftail;
unsigned long err;
@@ -106,7 +106,7 @@ compat_user_backtrace(struct compat_frame_tail __user *tail,
}
#endif /* CONFIG_COMPAT */

-void perf_callchain_user(struct perf_callchain_entry *entry,
+void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
@@ -122,7 +122,7 @@ void perf_callchain_user(struct perf_callchain_entry *entry,

tail = (struct frame_tail __user *)regs->regs[29];

- while (entry->nr < sysctl_perf_event_max_stack &&
+ while (entry->entry->nr < entry->max_stack &&
tail && !((unsigned long)tail & 0xf))
tail = user_backtrace(tail, entry);
} else {
@@ -132,7 +132,7 @@ void perf_callchain_user(struct perf_callchain_entry *entry,

tail = (struct compat_frame_tail __user *)regs->compat_fp - 1;

- while ((entry->nr < sysctl_perf_event_max_stack) &&
+ while ((entry->entry->nr < entry->max_stack) &&
tail && !((unsigned long)tail & 0x3))
tail = compat_user_backtrace(tail, entry);
#endif
@@ -146,12 +146,12 @@ void perf_callchain_user(struct perf_callchain_entry *entry,
*/
static int callchain_trace(struct stackframe *frame, void *data)
{
- struct perf_callchain_entry *entry = data;
+ struct perf_callchain_entry_ctx *entry = data;
perf_callchain_store(entry, frame->pc);
return 0;
}

-void perf_callchain_kernel(struct perf_callchain_entry *entry,
+void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
struct stackframe frame;
diff --git a/arch/metag/kernel/perf_callchain.c b/arch/metag/kernel/perf_callchain.c
index 252abc12a5a3..b3261a98b15b 100644
--- a/arch/metag/kernel/perf_callchain.c
+++ b/arch/metag/kernel/perf_callchain.c
@@ -29,7 +29,7 @@ static bool is_valid_call(unsigned long calladdr)

static struct metag_frame __user *
user_backtrace(struct metag_frame __user *user_frame,
- struct perf_callchain_entry *entry)
+ struct perf_callchain_entry_ctx *entry)
{
struct metag_frame frame;
unsigned long calladdr;
@@ -56,7 +56,7 @@ user_backtrace(struct metag_frame __user *user_frame,
}

void
-perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
unsigned long sp = regs->ctx.AX[0].U0;
struct metag_frame __user *frame;
@@ -65,7 +65,7 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)

--frame;

- while ((entry->nr < sysctl_perf_event_max_stack) && frame)
+ while ((entry->entry->nr < entry->max_stack) && frame)
frame = user_backtrace(frame, entry);
}

@@ -78,13 +78,13 @@ static int
callchain_trace(struct stackframe *fr,
void *data)
{
- struct perf_callchain_entry *entry = data;
+ struct perf_callchain_entry_ctx *entry = data;
perf_callchain_store(entry, fr->pc);
return 0;
}

void
-perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
struct stackframe fr;

diff --git a/arch/mips/kernel/perf_event.c b/arch/mips/kernel/perf_event.c
index 5021c546ad07..22395c7d7030 100644
--- a/arch/mips/kernel/perf_event.c
+++ b/arch/mips/kernel/perf_event.c
@@ -25,8 +25,8 @@
* the user stack callchains, we will add it here.
*/

-static void save_raw_perf_callchain(struct perf_callchain_entry *entry,
- unsigned long reg29)
+static void save_raw_perf_callchain(struct perf_callchain_entry_ctx *entry,
+ unsigned long reg29)
{
unsigned long *sp = (unsigned long *)reg29;
unsigned long addr;
@@ -35,14 +35,14 @@ static void save_raw_perf_callchain(struct perf_callchain_entry *entry,
addr = *sp++;
if (__kernel_text_address(addr)) {
perf_callchain_store(entry, addr);
- if (entry->nr >= sysctl_perf_event_max_stack)
+ if (entry->entry->nr >= entry->max_stack)
break;
}
}
}

-void perf_callchain_kernel(struct perf_callchain_entry *entry,
- struct pt_regs *regs)
+void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
{
unsigned long sp = regs->regs[29];
#ifdef CONFIG_KALLSYMS
@@ -59,7 +59,7 @@ void perf_callchain_kernel(struct perf_callchain_entry *entry,
}
do {
perf_callchain_store(entry, pc);
- if (entry->nr >= sysctl_perf_event_max_stack)
+ if (entry->entry->nr >= entry->max_stack)
break;
pc = unwind_stack(current, &sp, pc, &ra);
} while (pc);
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index 22d9015c1acc..c9260c1dfdbc 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -47,7 +47,7 @@ static int valid_next_sp(unsigned long sp, unsigned long prev_sp)
}

void
-perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
unsigned long sp, next_sp;
unsigned long next_ip;
@@ -232,7 +232,7 @@ static int sane_signal_64_frame(unsigned long sp)
puc == (unsigned long) &sf->uc;
}

-static void perf_callchain_user_64(struct perf_callchain_entry *entry,
+static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
unsigned long sp, next_sp;
@@ -247,7 +247,7 @@ static void perf_callchain_user_64(struct perf_callchain_entry *entry,
sp = regs->gpr[1];
perf_callchain_store(entry, next_ip);

- while (entry->nr < sysctl_perf_event_max_stack) {
+ while (entry->entry->nr < entry->max_stack) {
fp = (unsigned long __user *) sp;
if (!valid_user_sp(sp, 1) || read_user_stack_64(fp, &next_sp))
return;
@@ -319,7 +319,7 @@ static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
return rc;
}

-static inline void perf_callchain_user_64(struct perf_callchain_entry *entry,
+static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
}
@@ -439,7 +439,7 @@ static unsigned int __user *signal_frame_32_regs(unsigned int sp,
return mctx->mc_gregs;
}

-static void perf_callchain_user_32(struct perf_callchain_entry *entry,
+static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
unsigned int sp, next_sp;
@@ -453,7 +453,7 @@ static void perf_callchain_user_32(struct perf_callchain_entry *entry,
sp = regs->gpr[1];
perf_callchain_store(entry, next_ip);

- while (entry->nr < sysctl_perf_event_max_stack) {
+ while (entry->entry->nr < entry->max_stack) {
fp = (unsigned int __user *) (unsigned long) sp;
if (!valid_user_sp(sp, 0) || read_user_stack_32(fp, &next_sp))
return;
@@ -487,7 +487,7 @@ static void perf_callchain_user_32(struct perf_callchain_entry *entry,
}

void
-perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
if (current_is_64bit())
perf_callchain_user_64(entry, regs);
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c
index c3e4099b60a5..87035fa58bbe 100644
--- a/arch/s390/kernel/perf_event.c
+++ b/arch/s390/kernel/perf_event.c
@@ -224,13 +224,13 @@ arch_initcall(service_level_perf_register);

static int __perf_callchain_kernel(void *data, unsigned long address)
{
- struct perf_callchain_entry *entry = data;
+ struct perf_callchain_entry_ctx *entry = data;

perf_callchain_store(entry, address);
return 0;
}

-void perf_callchain_kernel(struct perf_callchain_entry *entry,
+void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
if (user_mode(regs))
diff --git a/arch/sh/kernel/perf_callchain.c b/arch/sh/kernel/perf_callchain.c
index cc80b614b5fa..fa2c0cd23eaa 100644
--- a/arch/sh/kernel/perf_callchain.c
+++ b/arch/sh/kernel/perf_callchain.c
@@ -21,7 +21,7 @@ static int callchain_stack(void *data, char *name)

static void callchain_address(void *data, unsigned long addr, int reliable)
{
- struct perf_callchain_entry *entry = data;
+ struct perf_callchain_entry_ctx *entry = data;

if (reliable)
perf_callchain_store(entry, addr);
@@ -33,7 +33,7 @@ static const struct stacktrace_ops callchain_ops = {
};

void
-perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
perf_callchain_store(entry, regs->pc);

diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index a4b8b5aed21c..bcc5376db74b 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -1711,7 +1711,7 @@ static int __init init_hw_perf_events(void)
}
pure_initcall(init_hw_perf_events);

-void perf_callchain_kernel(struct perf_callchain_entry *entry,
+void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
unsigned long ksp, fp;
@@ -1756,7 +1756,7 @@ void perf_callchain_kernel(struct perf_callchain_entry *entry,
}
}
#endif
- } while (entry->nr < sysctl_perf_event_max_stack);
+ } while (entry->entry->nr < entry->max_stack);
}

static inline int
@@ -1769,7 +1769,7 @@ valid_user_frame(const void __user *fp, unsigned long size)
return (__range_not_ok(fp, size, TASK_SIZE) == 0);
}

-static void perf_callchain_user_64(struct perf_callchain_entry *entry,
+static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
unsigned long ufp;
@@ -1790,10 +1790,10 @@ static void perf_callchain_user_64(struct perf_callchain_entry *entry,
pc = sf.callers_pc;
ufp = (unsigned long)sf.fp + STACK_BIAS;
perf_callchain_store(entry, pc);
- } while (entry->nr < sysctl_perf_event_max_stack);
+ } while (entry->entry->nr < entry->max_stack);
}

-static void perf_callchain_user_32(struct perf_callchain_entry *entry,
+static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
unsigned long ufp;
@@ -1822,11 +1822,11 @@ static void perf_callchain_user_32(struct perf_callchain_entry *entry,
ufp = (unsigned long)sf.fp;
}
perf_callchain_store(entry, pc);
- } while (entry->nr < sysctl_perf_event_max_stack);
+ } while (entry->entry->nr < entry->max_stack);
}

void
-perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
u64 saved_fault_address = current_thread_info()->fault_address;
u8 saved_fault_code = get_thread_fault_code();
diff --git a/arch/tile/kernel/perf_event.c b/arch/tile/kernel/perf_event.c
index 8767060d70fb..6394c1ccb68e 100644
--- a/arch/tile/kernel/perf_event.c
+++ b/arch/tile/kernel/perf_event.c
@@ -941,7 +941,7 @@ arch_initcall(init_hw_perf_events);
/*
* Tile specific backtracing code for perf_events.
*/
-static inline void perf_callchain(struct perf_callchain_entry *entry,
+static inline void perf_callchain(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
struct KBacktraceIterator kbt;
@@ -992,13 +992,13 @@ static inline void perf_callchain(struct perf_callchain_entry *entry,
}
}

-void perf_callchain_user(struct perf_callchain_entry *entry,
+void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
perf_callchain(entry, regs);
}

-void perf_callchain_kernel(struct perf_callchain_entry *entry,
+void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
perf_callchain(entry, regs);
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 5e5e76a52f58..07f2b01cfb72 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2202,7 +2202,7 @@ static int backtrace_stack(void *data, char *name)

static int backtrace_address(void *data, unsigned long addr, int reliable)
{
- struct perf_callchain_entry *entry = data;
+ struct perf_callchain_entry_ctx *entry = data;

return perf_callchain_store(entry, addr);
}
@@ -2214,7 +2214,7 @@ static const struct stacktrace_ops backtrace_ops = {
};

void
-perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
/* TODO: We don't support guest os callchain now */
@@ -2268,7 +2268,7 @@ static unsigned long get_segment_base(unsigned int segment)
#include <asm/compat.h>

static inline int
-perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
+perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
{
/* 32-bit process in 64-bit kernel. */
unsigned long ss_base, cs_base;
@@ -2283,7 +2283,7 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)

fp = compat_ptr(ss_base + regs->bp);
pagefault_disable();
- while (entry->nr < sysctl_perf_event_max_stack) {
+ while (entry->entry->nr < entry->max_stack) {
unsigned long bytes;
frame.next_frame = 0;
frame.return_address = 0;
@@ -2309,14 +2309,14 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
}
#else
static inline int
-perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
+perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
{
return 0;
}
#endif

void
-perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
+perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
struct stack_frame frame;
const void __user *fp;
@@ -2343,7 +2343,7 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
return;

pagefault_disable();
- while (entry->nr < sysctl_perf_event_max_stack) {
+ while (entry->entry->nr < entry->max_stack) {
unsigned long bytes;
frame.next_frame = NULL;
frame.return_address = 0;
diff --git a/arch/xtensa/kernel/perf_event.c b/arch/xtensa/kernel/perf_event.c
index a6b00b3af429..ef90479e0397 100644
--- a/arch/xtensa/kernel/perf_event.c
+++ b/arch/xtensa/kernel/perf_event.c
@@ -323,23 +323,23 @@ static void xtensa_pmu_read(struct perf_event *event)

static int callchain_trace(struct stackframe *frame, void *data)
{
- struct perf_callchain_entry *entry = data;
+ struct perf_callchain_entry_ctx *entry = data;

perf_callchain_store(entry, frame->pc);
return 0;
}

-void perf_callchain_kernel(struct perf_callchain_entry *entry,
+void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
- xtensa_backtrace_kernel(regs, sysctl_perf_event_max_stack,
+ xtensa_backtrace_kernel(regs, entry->max_stack,
callchain_trace, NULL, entry);
}

-void perf_callchain_user(struct perf_callchain_entry *entry,
+void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
- xtensa_backtrace_user(regs, sysctl_perf_event_max_stack,
+ xtensa_backtrace_user(regs, entry->max_stack,
callchain_trace, entry);
}

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 9e1c3ada91c4..dbd18246b36e 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -61,6 +61,11 @@ struct perf_callchain_entry {
__u64 ip[0]; /* /proc/sys/kernel/perf_event_max_stack */
};

+struct perf_callchain_entry_ctx {
+ struct perf_callchain_entry *entry;
+ u32 max_stack;
+};
+
struct perf_raw_record {
u32 size;
void *data;
@@ -1063,19 +1068,20 @@ extern void perf_event_fork(struct task_struct *tsk);
/* Callchains */
DECLARE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry);

-extern void perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs);
-extern void perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs);
+extern void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs);
+extern void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs);
extern struct perf_callchain_entry *
get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
- bool crosstask, bool add_mark);
+ u32 max_stack, bool crosstask, bool add_mark);
extern int get_callchain_buffers(void);
extern void put_callchain_buffers(void);

extern int sysctl_perf_event_max_stack;

-static inline int perf_callchain_store(struct perf_callchain_entry *entry, u64 ip)
+static inline int perf_callchain_store(struct perf_callchain_entry_ctx *ctx, u64 ip)
{
- if (entry->nr < sysctl_perf_event_max_stack) {
+ struct perf_callchain_entry *entry = ctx->entry;
+ if (entry->nr < ctx->max_stack) {
entry->ip[entry->nr++] = ip;
return 0;
} else {
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index f5a19548be12..a82d7605db3f 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -136,7 +136,8 @@ static u64 bpf_get_stackid(u64 r1, u64 r2, u64 flags, u64 r4, u64 r5)
BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))
return -EINVAL;

- trace = get_perf_callchain(regs, init_nr, kernel, user, false, false);
+ trace = get_perf_callchain(regs, init_nr, kernel, user,
+ sysctl_perf_event_max_stack, false, false);

if (unlikely(!trace))
/* couldn't fetch the stack trace */
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 7fc89939ede9..af95ad92893a 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -32,12 +32,12 @@ static DEFINE_MUTEX(callchain_mutex);
static struct callchain_cpus_entries *callchain_cpus_entries;


-__weak void perf_callchain_kernel(struct perf_callchain_entry *entry,
+__weak void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
}

-__weak void perf_callchain_user(struct perf_callchain_entry *entry,
+__weak void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
}
@@ -176,14 +176,15 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
if (!kernel && !user)
return NULL;

- return get_perf_callchain(regs, 0, kernel, user, crosstask, true);
+ return get_perf_callchain(regs, 0, kernel, user, sysctl_perf_event_max_stack, crosstask, true);
}

struct perf_callchain_entry *
get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
- bool crosstask, bool add_mark)
+ u32 max_stack, bool crosstask, bool add_mark)
{
struct perf_callchain_entry *entry;
+ struct perf_callchain_entry_ctx ctx;
int rctx;

entry = get_callchain_entry(&rctx);
@@ -193,12 +194,15 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
if (!entry)
goto exit_put;

+ ctx.entry = entry;
+ ctx.max_stack = max_stack;
+
entry->nr = init_nr;

if (kernel && !user_mode(regs)) {
if (add_mark)
- perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
- perf_callchain_kernel(entry, regs);
+ perf_callchain_store(&ctx, PERF_CONTEXT_KERNEL);
+ perf_callchain_kernel(&ctx, regs);
}

if (user) {
@@ -214,8 +218,8 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
goto exit_put;

if (add_mark)
- perf_callchain_store(entry, PERF_CONTEXT_USER);
- perf_callchain_user(entry, regs);
+ perf_callchain_store(&ctx, PERF_CONTEXT_USER);
+ perf_callchain_user(&ctx, regs);
}
}

--
2.5.5