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Commit 56962b44 authored by Frederic Weisbecker's avatar Frederic Weisbecker
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perf: Generalize some arch callchain code 

- Most archs use one callchain buffer per cpu, except x86 that needs
  to deal with NMIs. Provide a default perf_callchain_buffer()
  implementation that x86 overrides.

- Centralize all the kernel/user regs handling and invoke new arch
  handlers from there: perf_callchain_user() / perf_callchain_kernel()
  That avoid all the user_mode(), current->mm checks and so...

- Invert some parameters in perf_callchain_*() helpers: entry to the
  left, regs to the right, following the traditional (dst, src).
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: default avatarPaul Mackerras <paulus@samba.org>
Tested-by: default avatarWill Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Borislav Petkov <bp@amd64.org>
parent 70791ce9
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Inline Side-by-side
Showing with 90 additions and 180 deletions
arch/arm/kernel/perf_event.c
View file @ 56962b44
......@@ -3044,17 +3044,13 @@ user_backtrace(struct frame_tail *tail,
return buftail.fp - 1;
}
static void
perf_callchain_user(struct pt_regs *regs,
struct perf_callchain_entry *entry)
void
perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct frame_tail *tail;
perf_callchain_store(entry, PERF_CONTEXT_USER);
if (!user_mode(regs))
regs = task_pt_regs(current);
tail = (struct frame_tail *)regs->ARM_fp - 1;
while (tail && !((unsigned long)tail & 0x3))
......@@ -3075,9 +3071,8 @@ callchain_trace(struct stackframe *fr,
return 0;
}
static void
perf_callchain_kernel(struct pt_regs *regs,
struct perf_callchain_entry *entry)
void
perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct stackframe fr;
......@@ -3088,33 +3083,3 @@ perf_callchain_kernel(struct pt_regs *regs,
fr.pc = regs->ARM_pc;
walk_stackframe(&fr, callchain_trace, entry);
}
static void
perf_do_callchain(struct pt_regs *regs,
struct perf_callchain_entry *entry)
{
int is_user;
if (!regs)
return;
is_user = user_mode(regs);
if (!is_user)
perf_callchain_kernel(regs, entry);
if (current->mm)
perf_callchain_user(regs, entry);
}
static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry);
struct perf_callchain_entry *
perf_callchain(struct pt_regs *regs)
{
struct perf_callchain_entry *entry = &__get_cpu_var(pmc_irq_entry);
entry->nr = 0;
perf_do_callchain(regs, entry);
return entry;
}
arch/powerpc/kernel/perf_callchain.c
View file @ 56962b44
......@@ -46,8 +46,8 @@ static int valid_next_sp(unsigned long sp, unsigned long prev_sp)
return 0;
}
static void perf_callchain_kernel(struct pt_regs *regs,
struct perf_callchain_entry *entry)
void
perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
unsigned long sp, next_sp;
unsigned long next_ip;
......@@ -221,8 +221,8 @@ static int sane_signal_64_frame(unsigned long sp)
puc == (unsigned long) &sf->uc;
}
static void perf_callchain_user_64(struct pt_regs *regs,
struct perf_callchain_entry *entry)
static void perf_callchain_user_64(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
unsigned long sp, next_sp;
unsigned long next_ip;
......@@ -303,8 +303,8 @@ static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
return __get_user_inatomic(*ret, ptr);
}
static inline void perf_callchain_user_64(struct pt_regs *regs,
struct perf_callchain_entry *entry)
static inline void perf_callchain_user_64(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
}
......@@ -423,8 +423,8 @@ static unsigned int __user *signal_frame_32_regs(unsigned int sp,
return mctx->mc_gregs;
}
static void perf_callchain_user_32(struct pt_regs *regs,
struct perf_callchain_entry *entry)
static void perf_callchain_user_32(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
unsigned int sp, next_sp;
unsigned int next_ip;
......@@ -471,32 +471,11 @@ static void perf_callchain_user_32(struct pt_regs *regs,
}
}
/*
* Since we can't get PMU interrupts inside a PMU interrupt handler,
* we don't need separate irq and nmi entries here.
*/
static DEFINE_PER_CPU(struct perf_callchain_entry, cpu_perf_callchain);
struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
void
perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct perf_callchain_entry *entry = &__get_cpu_var(cpu_perf_callchain);
entry->nr = 0;
if (!user_mode(regs)) {
perf_callchain_kernel(regs, entry);
if (current->mm)
regs = task_pt_regs(current);
else
regs = NULL;
}
if (regs) {
if (current_is_64bit())
perf_callchain_user_64(regs, entry);
else
perf_callchain_user_32(regs, entry);
}
return entry;
if (current_is_64bit())
perf_callchain_user_64(entry, regs);
else
perf_callchain_user_32(entry, regs);
}
arch/sh/kernel/perf_callchain.c
View file @ 56962b44
......@@ -44,44 +44,11 @@ static const struct stacktrace_ops callchain_ops = {
.address = callchain_address,
};
static void
perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry)
void
perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
perf_callchain_store(entry, regs->pc);
unwind_stack(NULL, regs, NULL, &callchain_ops, entry);
}
static void
perf_do_callchain(struct pt_regs *regs, struct perf_callchain_entry *entry)
{
int is_user;
if (!regs)
return;
is_user = user_mode(regs);
/*
* Only the kernel side is implemented for now.
*/
if (!is_user)
perf_callchain_kernel(regs, entry);
}
/*
* No need for separate IRQ and NMI entries.
*/
static DEFINE_PER_CPU(struct perf_callchain_entry, callchain);
struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
{
struct perf_callchain_entry *entry = &__get_cpu_var(callchain);
entry->nr = 0;
perf_do_callchain(regs, entry);
return entry;
}
arch/sparc/kernel/perf_event.c
View file @ 56962b44
......@@ -1283,14 +1283,16 @@ void __init init_hw_perf_events(void)
register_die_notifier(&perf_event_nmi_notifier);
}
static void perf_callchain_kernel(struct pt_regs *regs,
struct perf_callchain_entry *entry)
void perf_callchain_kernel(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
unsigned long ksp, fp;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
int graph = 0;
#endif
stack_trace_flush();
perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
perf_callchain_store(entry, regs->tpc);
......@@ -1330,8 +1332,8 @@ static void perf_callchain_kernel(struct pt_regs *regs,
} while (entry->nr < PERF_MAX_STACK_DEPTH);
}
static void perf_callchain_user_64(struct pt_regs *regs,
struct perf_callchain_entry *entry)
static void perf_callchain_user_64(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
unsigned long ufp;
......@@ -1353,8 +1355,8 @@ static void perf_callchain_user_64(struct pt_regs *regs,
} while (entry->nr < PERF_MAX_STACK_DEPTH);
}
static void perf_callchain_user_32(struct pt_regs *regs,
struct perf_callchain_entry *entry)
static void perf_callchain_user_32(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
unsigned long ufp;
......@@ -1376,30 +1378,12 @@ static void perf_callchain_user_32(struct pt_regs *regs,
} while (entry->nr < PERF_MAX_STACK_DEPTH);
}
/* Like powerpc we can't get PMU interrupts within the PMU handler,
* so no need for separate NMI and IRQ chains as on x86.
*/
static DEFINE_PER_CPU(struct perf_callchain_entry, callchain);
struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
void
perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct perf_callchain_entry *entry = &__get_cpu_var(callchain);
entry->nr = 0;
if (!user_mode(regs)) {
stack_trace_flush();
perf_callchain_kernel(regs, entry);
if (current->mm)
regs = task_pt_regs(current);
else
regs = NULL;
}
if (regs) {
flushw_user();
if (test_thread_flag(TIF_32BIT))
perf_callchain_user_32(regs, entry);
else
perf_callchain_user_64(regs, entry);
}
return entry;
flushw_user();
if (test_thread_flag(TIF_32BIT))
perf_callchain_user_32(entry, regs);
else
perf_callchain_user_64(entry, regs);
}
arch/x86/kernel/cpu/perf_event.c
View file @ 56962b44
......@@ -1571,9 +1571,7 @@ const struct pmu *hw_perf_event_init(struct perf_event *event)
* callchain support
*/
static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry);
static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_nmi_entry);
static DEFINE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry_nmi);
static void
......@@ -1607,8 +1605,8 @@ static const struct stacktrace_ops backtrace_ops = {
.walk_stack = print_context_stack_bp,
};
static void
perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry)
void
perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
perf_callchain_store(entry, regs->ip);
......@@ -1653,14 +1651,12 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
}
#endif
static void
perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry)
void
perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct stack_frame frame;
const void __user *fp;
if (!user_mode(regs))
regs = task_pt_regs(current);
fp = (void __user *)regs->bp;
......@@ -1687,42 +1683,17 @@ perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry)
}
}
static void
perf_do_callchain(struct pt_regs *regs, struct perf_callchain_entry *entry)
{
int is_user;
if (!regs)
return;
is_user = user_mode(regs);
if (!is_user)
perf_callchain_kernel(regs, entry);
if (current->mm)
perf_callchain_user(regs, entry);
}
struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
struct perf_callchain_entry *perf_callchain_buffer(void)
{
struct perf_callchain_entry *entry;
if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
/* TODO: We don't support guest os callchain now */
return NULL;
}
if (in_nmi())
entry = &__get_cpu_var(pmc_nmi_entry);
else
entry = &__get_cpu_var(pmc_irq_entry);
entry->nr = 0;
perf_do_callchain(regs, entry);
return &__get_cpu_var(perf_callchain_entry_nmi);
return entry;
return &__get_cpu_var(perf_callchain_entry);
}
unsigned long perf_instruction_pointer(struct pt_regs *regs)
......
include/linux/perf_event.h
View file @ 56962b44
......@@ -976,7 +976,15 @@ extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
extern void perf_event_comm(struct task_struct *tsk);
extern void perf_event_fork(struct task_struct *tsk);
extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
/* 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 struct perf_callchain_entry *perf_callchain_buffer(void);
static inline void
perf_callchain_store(struct perf_callchain_entry *entry, u64 ip)
......
kernel/perf_event.c
View file @ 56962b44
......@@ -2937,13 +2937,49 @@ void perf_event_do_pending(void)
__perf_pending_run();
}
DEFINE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry);
/*
* Callchain support -- arch specific
*/
__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
__weak struct perf_callchain_entry *perf_callchain_buffer(void)
{
return NULL;
return &__get_cpu_var(perf_callchain_entry);
}
__weak void perf_callchain_kernel(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
}
__weak void perf_callchain_user(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
}
static struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
{
struct perf_callchain_entry *entry;
entry = perf_callchain_buffer();
if (!entry)
return NULL;
entry->nr = 0;
if (!user_mode(regs)) {
perf_callchain_kernel(entry, regs);
if (current->mm)
regs = task_pt_regs(current);
else
regs = NULL;
}
if (regs)
perf_callchain_user(entry, regs);
return entry;
}
......
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