From 6308191f6f55d3629c7dbe72dfb856ad9fa560fd Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 30 Mar 2012 18:26:36 +0200 Subject: [PATCH 1/2] tracing, sched, vfs: Fix 'old_pid' usage in trace_sched_process_exec() 1. TRACE_EVENT(sched_process_exec) forgets to actually use the old pid argument, it sets ->old_pid = p->pid. 2. search_binary_handler() uses the wrong pid number. tracepoint needs the global pid_t from the root namespace, while old_pid is the virtual pid number as it seen by the tracer/parent. With this patch we have two pid_t's in search_binary_handler(), not really nice. Perhaps we should switch to "struct pid*", but in this case it would be better to cleanup the current code first and move the "depth == 0" code outside. Signed-off-by: Oleg Nesterov Cc: David Smith Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Denys Vlasenko Link: http://lkml.kernel.org/r/20120330162636.GA4857@redhat.com Signed-off-by: Ingo Molnar --- fs/exec.c | 7 ++++--- include/trace/events/sched.h | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 23559c227d9c..644f6c4eb606 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1370,7 +1370,7 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) unsigned int depth = bprm->recursion_depth; int try,retval; struct linux_binfmt *fmt; - pid_t old_pid; + pid_t old_pid, old_vpid; retval = security_bprm_check(bprm); if (retval) @@ -1381,8 +1381,9 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) return retval; /* Need to fetch pid before load_binary changes it */ + old_pid = current->pid; rcu_read_lock(); - old_pid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); + old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); rcu_read_unlock(); retval = -ENOENT; @@ -1405,7 +1406,7 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) if (retval >= 0) { if (depth == 0) { trace_sched_process_exec(current, old_pid, bprm); - ptrace_event(PTRACE_EVENT_EXEC, old_pid); + ptrace_event(PTRACE_EVENT_EXEC, old_vpid); } put_binfmt(fmt); allow_write_access(bprm->file); diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index fbc7b1ad929b..ea7a2035456d 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -295,7 +295,7 @@ TRACE_EVENT(sched_process_exec, TP_fast_assign( __assign_str(filename, bprm->filename); __entry->pid = p->pid; - __entry->old_pid = p->pid; + __entry->old_pid = old_pid; ), TP_printk("filename=%s pid=%d old_pid=%d", __get_str(filename), From 7b8e6da46b921d30ac1553cac56d8fb74f0b431d Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 27 Mar 2012 16:50:42 +0200 Subject: [PATCH 2/2] perf/x86/p4: Add format attributes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Steven reported his P4 not booting properly, the missing format attributes cause a NULL ptr deref. Cure this by adding the missing format specification. I took the format description out of the comment near p4_config_pack*() and hope that comment is still relatively accurate. Reported-by: Steven Rostedt Reported-by: Bruno Prémont Tested-by: Steven Rostedt Signed-off-by: Peter Zijlstra Cc: Jiri Olsa Cc: Cyrill Gorcunov Cc: Lin Ming Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1332859842.16159.227.camel@twins Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_p4.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c index ef484d9d0a25..a2dfacfd7103 100644 --- a/arch/x86/kernel/cpu/perf_event_p4.c +++ b/arch/x86/kernel/cpu/perf_event_p4.c @@ -1271,6 +1271,17 @@ static int p4_pmu_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign return num ? -EINVAL : 0; } +PMU_FORMAT_ATTR(cccr, "config:0-31" ); +PMU_FORMAT_ATTR(escr, "config:32-62"); +PMU_FORMAT_ATTR(ht, "config:63" ); + +static struct attribute *intel_p4_formats_attr[] = { + &format_attr_cccr.attr, + &format_attr_escr.attr, + &format_attr_ht.attr, + NULL, +}; + static __initconst const struct x86_pmu p4_pmu = { .name = "Netburst P4/Xeon", .handle_irq = p4_pmu_handle_irq, @@ -1305,6 +1316,8 @@ static __initconst const struct x86_pmu p4_pmu = { * the former idea is taken from OProfile code */ .perfctr_second_write = 1, + + .format_attrs = intel_p4_formats_attr, }; __init int p4_pmu_init(void)