diff options
30 files changed, 201 insertions, 117 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index daabdd7ee543..a3683ce2a2f3 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -61,6 +61,7 @@ show up in /proc/sys/kernel: - perf_cpu_time_max_percent - perf_event_paranoid - perf_event_max_stack +- perf_event_max_contexts_per_stack - pid_max - powersave-nap [ PPC only ] - printk @@ -668,6 +669,19 @@ The default value is 127. ============================================================== +perf_event_max_contexts_per_stack: + +Controls maximum number of stack frame context entries for +(attr.sample_type & PERF_SAMPLE_CALLCHAIN) configured events, for +instance, when using 'perf record -g' or 'perf trace --call-graph fp'. + +This can only be done when no events are in use that have callchains +enabled, otherwise writing to this file will return -EBUSY. + +The default value is 8. + +============================================================== + pid_max: PID allocation wrap value. When the kernel's next PID value 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..22bf1f64d99a 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->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..713ca824f266 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->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->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..3e8e048040df 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->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..d64056e0bb56 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->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->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..f62597dbd757 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; @@ -76,7 +76,7 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) next_ip = regs->nip; lr = regs->link; level = 0; - perf_callchain_store(entry, PERF_CONTEXT_KERNEL); + perf_callchain_store_context(entry, PERF_CONTEXT_KERNEL); } else { if (level == 0) @@ -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->nr < entry->max_stack) { fp = (unsigned long __user *) sp; if (!valid_user_sp(sp, 1) || read_user_stack_64(fp, &next_sp)) return; @@ -274,7 +274,7 @@ static void perf_callchain_user_64(struct perf_callchain_entry *entry, read_user_stack_64(&uregs[PT_R1], &sp)) return; level = 0; - perf_callchain_store(entry, PERF_CONTEXT_USER); + perf_callchain_store_context(entry, PERF_CONTEXT_USER); perf_callchain_store(entry, next_ip); continue; } @@ -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->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; @@ -473,7 +473,7 @@ static void perf_callchain_user_32(struct perf_callchain_entry *entry, read_user_stack_32(&uregs[PT_R1], &sp)) return; level = 0; - perf_callchain_store(entry, PERF_CONTEXT_USER); + perf_callchain_store_context(entry, PERF_CONTEXT_USER); perf_callchain_store(entry, next_ip); continue; } @@ -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..710f3278d448 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->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->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->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 73a75aa5a66d..33787ee817f0 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->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->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..6b87be908790 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -61,6 +61,14 @@ 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; + u32 nr; + short contexts; + bool contexts_maxed; +}; + struct perf_raw_record { u32 size; void *data; @@ -1063,20 +1071,36 @@ 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; +extern int sysctl_perf_event_max_contexts_per_stack; + +static inline int perf_callchain_store_context(struct perf_callchain_entry_ctx *ctx, u64 ip) +{ + if (ctx->contexts < sysctl_perf_event_max_contexts_per_stack) { + struct perf_callchain_entry *entry = ctx->entry; + entry->ip[entry->nr++] = ip; + ++ctx->contexts; + return 0; + } else { + ctx->contexts_maxed = true; + return -1; /* no more room, stop walking the 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) { + if (ctx->nr < ctx->max_stack && !ctx->contexts_maxed) { + struct perf_callchain_entry *entry = ctx->entry; entry->ip[entry->nr++] = ip; + ++ctx->nr; return 0; } else { return -1; /* no more room, stop walking the stack */ diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 43fc8d213472..36ce552cf6a9 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -862,6 +862,7 @@ enum perf_event_type { }; #define PERF_MAX_STACK_DEPTH 127 +#define PERF_MAX_CONTEXTS_PER_STACK 8 enum perf_callchain_context { PERF_CONTEXT_HV = (__u64)-32, 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 b9325e7dcba1..179ef4640964 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -19,11 +19,13 @@ struct callchain_cpus_entries { }; int sysctl_perf_event_max_stack __read_mostly = PERF_MAX_STACK_DEPTH; +int sysctl_perf_event_max_contexts_per_stack __read_mostly = PERF_MAX_CONTEXTS_PER_STACK; static inline size_t perf_callchain_entry__sizeof(void) { return (sizeof(struct perf_callchain_entry) + - sizeof(__u64) * sysctl_perf_event_max_stack); + sizeof(__u64) * (sysctl_perf_event_max_stack + + sysctl_perf_event_max_contexts_per_stack)); } static DEFINE_PER_CPU(int, callchain_recursion[PERF_NR_CONTEXTS]); @@ -32,12 +34,12 @@ 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 +178,15 @@ 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 +196,16 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, if (!entry) goto exit_put; - entry->nr = init_nr; + ctx.entry = entry; + ctx.max_stack = max_stack; + ctx.nr = entry->nr = init_nr; + ctx.contexts = 0; + ctx.contexts_maxed = false; if (kernel && !user_mode(regs)) { if (add_mark) - perf_callchain_store(entry, PERF_CONTEXT_KERNEL); - perf_callchain_kernel(entry, regs); + perf_callchain_store_context(&ctx, PERF_CONTEXT_KERNEL); + perf_callchain_kernel(&ctx, regs); } if (user) { @@ -214,8 +221,8 @@ 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_context(&ctx, PERF_CONTEXT_USER); + perf_callchain_user(&ctx, regs); } } @@ -225,10 +232,15 @@ exit_put: return entry; } +/* + * Used for sysctl_perf_event_max_stack and + * sysctl_perf_event_max_contexts_per_stack. + */ int perf_event_max_stack_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - int new_value = sysctl_perf_event_max_stack, ret; + int *value = table->data; + int new_value = *value, ret; struct ctl_table new_table = *table; new_table.data = &new_value; @@ -240,7 +252,7 @@ int perf_event_max_stack_handler(struct ctl_table *table, int write, if (atomic_read(&nr_callchain_events)) ret = -EBUSY; else - sysctl_perf_event_max_stack = new_value; + *value = new_value; mutex_unlock(&callchain_mutex); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c8b318663525..bec4c11c47d6 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1149,13 +1149,22 @@ static struct ctl_table kern_table[] = { }, { .procname = "perf_event_max_stack", - .data = NULL, /* filled in by handler */ + .data = &sysctl_perf_event_max_stack, .maxlen = sizeof(sysctl_perf_event_max_stack), .mode = 0644, .proc_handler = perf_event_max_stack_handler, .extra1 = &zero, .extra2 = &six_hundred_forty_kb, }, + { + .procname = "perf_event_max_contexts_per_stack", + .data = &sysctl_perf_event_max_contexts_per_stack, + .maxlen = sizeof(sysctl_perf_event_max_contexts_per_stack), + .mode = 0644, + .proc_ha |