From f431b634f24d099872e78acc356c7fd35913b36b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 12 Feb 2013 16:18:59 -0500 Subject: [PATCH 1/3] tracing/syscalls: Allow archs to ignore tracing compat syscalls The tracing of ia32 compat system calls has been a bit of a pain as they use different system call numbers than the 64bit equivalents. I wrote a simple 'lls' program that lists files. I compiled it as a i686 ELF binary and ran it under a x86_64 box. This is the result: echo 0 > /debug/tracing/tracing_on echo 1 > /debug/tracing/events/syscalls/enable echo 1 > /debug/tracing/tracing_on ; ./lls ; echo 0 > /debug/tracing/tracing_on grep lls /debug/tracing/trace [.. skipping calls before TS_COMPAT is set ...] lls-1127 [005] d... 936.409188: sys_recvfrom(fd: 0, ubuf: 4d560fc4, size: 0, flags: 8048034, addr: 8, addr_len: f7700420) lls-1127 [005] d... 936.409190: sys_recvfrom -> 0x8a77000 lls-1127 [005] d... 936.409211: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) lls-1127 [005] d... 936.409215: sys_lgetxattr -> 0xf76ff000 lls-1127 [005] d... 936.409223: sys_dup2(oldfd: 4d55ae9b, newfd: 4) lls-1127 [005] d... 936.409228: sys_dup2 -> 0xfffffffffffffffe lls-1127 [005] d... 936.409236: sys_newfstat(fd: 4d55b085, statbuf: 80000) lls-1127 [005] d... 936.409242: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409243: sys_removexattr(pathname: 3, name: ffcd0060) lls-1127 [005] d... 936.409244: sys_removexattr -> 0x0 lls-1127 [005] d... 936.409245: sys_lgetxattr(pathname: 0, name: 19614, value: 1, size: 2) lls-1127 [005] d... 936.409248: sys_lgetxattr -> 0xf76e5000 lls-1127 [005] d... 936.409248: sys_newlstat(filename: 3, statbuf: 19614) lls-1127 [005] d... 936.409249: sys_newlstat -> 0x0 lls-1127 [005] d... 936.409262: sys_newfstat(fd: f76fb588, statbuf: 80000) lls-1127 [005] d... 936.409279: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409279: sys_close(fd: 3) lls-1127 [005] d... 936.421550: sys_close -> 0x200 lls-1127 [005] d... 936.421558: sys_removexattr(pathname: 3, name: ffcd00d0) lls-1127 [005] d... 936.421560: sys_removexattr -> 0x0 lls-1127 [005] d... 936.421569: sys_lgetxattr(pathname: 4d564000, name: 1b1abc, value: 5, size: 802) lls-1127 [005] d... 936.421574: sys_lgetxattr -> 0x4d564000 lls-1127 [005] d... 936.421575: sys_capget(header: 4d70f000, dataptr: 1000) lls-1127 [005] d... 936.421580: sys_capget -> 0x0 lls-1127 [005] d... 936.421580: sys_lgetxattr(pathname: 4d710000, name: 3000, value: 3, size: 812) lls-1127 [005] d... 936.421589: sys_lgetxattr -> 0x4d710000 lls-1127 [005] d... 936.426130: sys_lgetxattr(pathname: 4d713000, name: 2abc, value: 3, size: 32) lls-1127 [005] d... 936.426141: sys_lgetxattr -> 0x4d713000 lls-1127 [005] d... 936.426145: sys_newlstat(filename: 3, statbuf: f76ff3f0) lls-1127 [005] d... 936.426146: sys_newlstat -> 0x0 lls-1127 [005] d... 936.431748: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) Obviously I'm not calling newfstat with a fd of 4d55b085. The calls are obviously incorrect, and confusing. Other efforts have been made to fix this: https://lkml.org/lkml/2012/3/26/367 But the real solution is to rewrite the syscall internals and come up with a fixed solution. One that doesn't require all the kluge that the current solution has. Thus for now, instead of outputting incorrect data, simply ignore them. With this patch the changes now have: #> grep lls /debug/tracing/trace #> Compat system calls simply are not traced. If users need compat syscalls, then they should just use the raw syscall tracepoints. For an architecture to make their compat syscalls ignored, it must define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS (done in asm/ftrace.h) and also define an arch_trace_is_compat_syscall() function that will return true if the current task should ignore tracing the syscall. I want to stress that this change does not affect actual syscalls in any way, shape or form. It is only used within the tracing system and doesn't interfere with the syscall logic at all. The changes are consolidated nicely into trace_syscalls.c and asm/ftrace.h. I had to make one small modification to asm/thread_info.h and that was to remove the include of asm/ftrace.h. As asm/ftrace.h required the current_thread_info() it was causing include hell. That include was added back in 2008 when the function graph tracer was added: commit caf4b323 "tracing, x86: add low level support for ftrace return tracing" It does not need to be included there. Link: http://lkml.kernel.org/r/1360703939.21867.99.camel@gandalf.local.home Acked-by: H. Peter Anvin Signed-off-by: Steven Rostedt --- arch/x86/include/asm/ftrace.h | 24 +++++++++++++++++ arch/x86/include/asm/thread_info.h | 1 - kernel/trace/trace_syscalls.c | 43 ++++++++++++++++++++++++++---- 3 files changed, 62 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h index 86cb51e1ca96..0525a8bdf65d 100644 --- a/arch/x86/include/asm/ftrace.h +++ b/arch/x86/include/asm/ftrace.h @@ -72,4 +72,28 @@ int ftrace_int3_handler(struct pt_regs *regs); #endif /* __ASSEMBLY__ */ #endif /* CONFIG_FUNCTION_TRACER */ + +#if !defined(__ASSEMBLY__) && !defined(COMPILE_OFFSETS) + +#if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_IA32_EMULATION) +#include + +/* + * Because ia32 syscalls do not map to x86_64 syscall numbers + * this screws up the trace output when tracing a ia32 task. + * Instead of reporting bogus syscalls, just do not trace them. + * + * If the user realy wants these, then they should use the + * raw syscall tracepoints with filtering. + */ +#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 1 +static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) +{ + if (is_compat_task()) + return true; + return false; +} +#endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_IA32_EMULATION */ +#endif /* !__ASSEMBLY__ && !COMPILE_OFFSETS */ + #endif /* _ASM_X86_FTRACE_H */ diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 2d946e63ee82..2cd056e3ada3 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -20,7 +20,6 @@ struct task_struct; struct exec_domain; #include -#include #include struct thread_info { diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 5329e13e74a1..7a809e321058 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -1,5 +1,6 @@ #include #include +#include #include #include #include /* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */ @@ -47,6 +48,38 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name } #endif +#ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS +/* + * Some architectures that allow for 32bit applications + * to run on a 64bit kernel, do not map the syscalls for + * the 32bit tasks the same as they do for 64bit tasks. + * + * *cough*x86*cough* + * + * In such a case, instead of reporting the wrong syscalls, + * simply ignore them. + * + * For an arch to ignore the compat syscalls it needs to + * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as + * define the function arch_trace_is_compat_syscall() to let + * the tracing system know that it should ignore it. + */ +static int +trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) +{ + if (unlikely(arch_trace_is_compat_syscall(regs))) + return -1; + + return syscall_get_nr(task, regs); +} +#else +static inline int +trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) +{ + return syscall_get_nr(task, regs); +} +#endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */ + static __init struct syscall_metadata * find_syscall_meta(unsigned long syscall) { @@ -276,10 +309,10 @@ static void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id) struct syscall_metadata *sys_data; struct ring_buffer_event *event; struct ring_buffer *buffer; - int size; int syscall_nr; + int size; - syscall_nr = syscall_get_nr(current, regs); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0) return; if (!test_bit(syscall_nr, enabled_enter_syscalls)) @@ -313,7 +346,7 @@ static void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret) struct ring_buffer *buffer; int syscall_nr; - syscall_nr = syscall_get_nr(current, regs); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0) return; if (!test_bit(syscall_nr, enabled_exit_syscalls)) @@ -502,7 +535,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) int rctx; int size; - syscall_nr = syscall_get_nr(current, regs); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0) return; if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) @@ -578,7 +611,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) int rctx; int size; - syscall_nr = syscall_get_nr(current, regs); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0) return; if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) From 8c189ea64eea01ca20d102ddb74d6936dd16c579 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 13 Feb 2013 15:18:38 -0500 Subject: [PATCH 2/3] ftrace: Call ftrace cleanup module notifier after all other notifiers Commit: c1bf08ac "ftrace: Be first to run code modification on modules" changed ftrace module notifier's priority to INT_MAX in order to process the ftrace nops before anything else could touch them (namely kprobes). This was the correct thing to do. Unfortunately, the ftrace module notifier also contains the ftrace clean up code. As opposed to the set up code, this code should be run *after* all the module notifiers have run in case a module is doing correct clean-up and unregisters its ftrace hooks. Basically, ftrace needs to do clean up on module removal, as it needs to know about code being removed so that it doesn't try to modify that code. But after it removes the module from its records, if a ftrace user tries to remove a probe, that removal will fail due as the record of that code segment no longer exists. Nothing really bad happens if the probe removal is called after ftrace did the clean up, but the ftrace removal function will return an error. Correct code (such as kprobes) will produce a WARN_ON() if it fails to remove the probe. As people get annoyed by frivolous warnings, it's best to do the ftrace clean up after everything else. By splitting the ftrace_module_notifier into two notifiers, one that does the module load setup that is run at high priority, and the other that is called for module clean up that is run at low priority, the problem is solved. Cc: stable@vger.kernel.org Reported-by: Frank Ch. Eigler Acked-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 46 ++++++++++++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 14 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index ce8c3d68292f..98ca94a41819 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3996,37 +3996,51 @@ static void ftrace_init_module(struct module *mod, ftrace_process_locs(mod, start, end); } -static int ftrace_module_notify(struct notifier_block *self, - unsigned long val, void *data) +static int ftrace_module_notify_enter(struct notifier_block *self, + unsigned long val, void *data) { struct module *mod = data; - switch (val) { - case MODULE_STATE_COMING: + if (val == MODULE_STATE_COMING) ftrace_init_module(mod, mod->ftrace_callsites, mod->ftrace_callsites + mod->num_ftrace_callsites); - break; - case MODULE_STATE_GOING: + return 0; +} + +static int ftrace_module_notify_exit(struct notifier_block *self, + unsigned long val, void *data) +{ + struct module *mod = data; + + if (val == MODULE_STATE_GOING) ftrace_release_mod(mod); - break; - } return 0; } #else -static int ftrace_module_notify(struct notifier_block *self, - unsigned long val, void *data) +static int ftrace_module_notify_enter(struct notifier_block *self, + unsigned long val, void *data) +{ + return 0; +} +static int ftrace_module_notify_exit(struct notifier_block *self, + unsigned long val, void *data) { return 0; } #endif /* CONFIG_MODULES */ -struct notifier_block ftrace_module_nb = { - .notifier_call = ftrace_module_notify, +struct notifier_block ftrace_module_enter_nb = { + .notifier_call = ftrace_module_notify_enter, .priority = INT_MAX, /* Run before anything that can use kprobes */ }; +struct notifier_block ftrace_module_exit_nb = { + .notifier_call = ftrace_module_notify_exit, + .priority = INT_MIN, /* Run after anything that can remove kprobes */ +}; + extern unsigned long __start_mcount_loc[]; extern unsigned long __stop_mcount_loc[]; @@ -4058,9 +4072,13 @@ void __init ftrace_init(void) __start_mcount_loc, __stop_mcount_loc); - ret = register_module_notifier(&ftrace_module_nb); + ret = register_module_notifier(&ftrace_module_enter_nb); if (ret) - pr_warning("Failed to register trace ftrace module notifier\n"); + pr_warning("Failed to register trace ftrace module enter notifier\n"); + + ret = register_module_notifier(&ftrace_module_exit_nb); + if (ret) + pr_warning("Failed to register trace ftrace module exit notifier\n"); set_ftrace_early_filters(); From 69943182bb9e19e4b60ea5033f683ec1af1703a9 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Wed, 20 Feb 2013 11:15:12 +0100 Subject: [PATCH 3/3] perf/x86: Add Intel IvyBridge event scheduling constraints Intel IvyBridge processor has different constraints compared to SandyBridge. Therefore it needs its own contraint table. This patch adds the constraint table. Without this patch, the events listed in the patch may not be scheduled correctly and bogus counts may be collected. Signed-off-by: Stephane Eranian Cc: peterz@infradead.org Cc: ak@linux.intel.com Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: namhyung.kim@lge.com Link: http://lkml.kernel.org/r/1361355312-3323-1-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 4914e94ad6e8..529c8931fc02 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -107,6 +107,27 @@ static struct event_constraint intel_snb_event_constraints[] __read_mostly = EVENT_CONSTRAINT_END }; +static struct event_constraint intel_ivb_event_constraints[] __read_mostly = +{ + FIXED_EVENT_CONSTRAINT(0x00c0, 0), /* INST_RETIRED.ANY */ + FIXED_EVENT_CONSTRAINT(0x003c, 1), /* CPU_CLK_UNHALTED.CORE */ + FIXED_EVENT_CONSTRAINT(0x0300, 2), /* CPU_CLK_UNHALTED.REF */ + INTEL_UEVENT_CONSTRAINT(0x0148, 0x4), /* L1D_PEND_MISS.PENDING */ + INTEL_UEVENT_CONSTRAINT(0x0279, 0xf), /* IDQ.EMTPY */ + INTEL_UEVENT_CONSTRAINT(0x019c, 0xf), /* IDQ_UOPS_NOT_DELIVERED.CORE */ + INTEL_UEVENT_CONSTRAINT(0x04a3, 0xf), /* CYCLE_ACTIVITY.CYCLES_NO_EXECUTE */ + INTEL_UEVENT_CONSTRAINT(0x05a3, 0xf), /* CYCLE_ACTIVITY.STALLS_L2_PENDING */ + INTEL_UEVENT_CONSTRAINT(0x06a3, 0xf), /* CYCLE_ACTIVITY.STALLS_LDM_PENDING */ + INTEL_UEVENT_CONSTRAINT(0x08a3, 0x4), /* CYCLE_ACTIVITY.CYCLES_L1D_PENDING */ + INTEL_UEVENT_CONSTRAINT(0x0ca3, 0x4), /* CYCLE_ACTIVITY.STALLS_L1D_PENDING */ + INTEL_UEVENT_CONSTRAINT(0x01c0, 0x2), /* INST_RETIRED.PREC_DIST */ + INTEL_EVENT_CONSTRAINT(0xd0, 0xf), /* MEM_UOPS_RETIRED.* */ + INTEL_EVENT_CONSTRAINT(0xd1, 0xf), /* MEM_LOAD_UOPS_RETIRED.* */ + INTEL_EVENT_CONSTRAINT(0xd2, 0xf), /* MEM_LOAD_UOPS_LLC_HIT_RETIRED.* */ + INTEL_EVENT_CONSTRAINT(0xd3, 0xf), /* MEM_LOAD_UOPS_LLC_MISS_RETIRED.* */ + EVENT_CONSTRAINT_END +}; + static struct extra_reg intel_westmere_extra_regs[] __read_mostly = { INTEL_EVENT_EXTRA_REG(0xb7, MSR_OFFCORE_RSP_0, 0xffff, RSP_0), @@ -2095,7 +2116,7 @@ __init int intel_pmu_init(void) intel_pmu_lbr_init_snb(); - x86_pmu.event_constraints = intel_snb_event_constraints; + x86_pmu.event_constraints = intel_ivb_event_constraints; x86_pmu.pebs_constraints = intel_ivb_pebs_event_constraints; x86_pmu.pebs_aliases = intel_pebs_aliases_snb; x86_pmu.extra_regs = intel_snb_extra_regs;