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| author | Matt Helsley <matthltc@us.ibm.com> | 2010-09-13 13:01:20 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-09-15 10:44:00 +0200 |
| commit | 38a81da2205f94e8a2a834b51a6b99c91fc7c2e8 (patch) | |
| tree | 5227c665f37d1c472608a44aaad0a04be68befb2 /kernel/watchdog.c | |
| parent | 2ebd4ffb6d0cb877787b1e42be8485820158857e (diff) | |
| download | linux-38a81da2205f94e8a2a834b51a6b99c91fc7c2e8.tar.gz linux-38a81da2205f94e8a2a834b51a6b99c91fc7c2e8.tar.bz2 linux-38a81da2205f94e8a2a834b51a6b99c91fc7c2e8.zip | |
perf events: Clean up pid passing
The kernel perf event creation path shouldn't use find_task_by_vpid()
because a vpid exists in a specific namespace. find_task_by_vpid() uses
current's pid namespace which isn't always the correct namespace to use
for the vpid in all the places perf_event_create_kernel_counter() (and
thus find_get_context()) is called.
The goal is to clean up pid namespace handling and prevent bugs like:
https://bugzilla.kernel.org/show_bug.cgi?id=17281
Instead of using pids switch find_get_context() to use task struct
pointers directly. The syscall is responsible for resolving the pid to
a task struct. This moves the pid namespace resolution into the syscall
much like every other syscall that takes pid parameters.
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robin Green <greenrd@greenrd.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
LKML-Reference: <a134e5e392ab0204961fd1a62c84a222bf5874a9.1284407763.git.matthltc@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/watchdog.c')
| -rw-r--r-- | kernel/watchdog.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 89eadbb9cefe..dc8e16824b51 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -358,7 +358,7 @@ static int watchdog_nmi_enable(int cpu) /* Try to register using hardware perf events */ wd_attr = &wd_hw_attr; wd_attr->sample_period = hw_nmi_get_sample_period(); - event = perf_event_create_kernel_counter(wd_attr, cpu, -1, watchdog_overflow_callback); + event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback); if (!IS_ERR(event)) { printk(KERN_INFO "NMI watchdog enabled, takes one hw-pmu counter.\n"); goto out_save; |