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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/hw_breakpoint.c | |
| parent | 2ebd4ffb6d0cb877787b1e42be8485820158857e (diff) | |
| download | op-kernel-dev-38a81da2205f94e8a2a834b51a6b99c91fc7c2e8.zip op-kernel-dev-38a81da2205f94e8a2a834b51a6b99c91fc7c2e8.tar.gz | |
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/hw_breakpoint.c')
| -rw-r--r-- | kernel/hw_breakpoint.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 6122f02..3b714e8 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -433,8 +433,7 @@ register_user_hw_breakpoint(struct perf_event_attr *attr, perf_overflow_handler_t triggered, struct task_struct *tsk) { - return perf_event_create_kernel_counter(attr, -1, task_pid_vnr(tsk), - triggered); + return perf_event_create_kernel_counter(attr, -1, tsk, triggered); } EXPORT_SYMBOL_GPL(register_user_hw_breakpoint); @@ -516,7 +515,7 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, get_online_cpus(); for_each_online_cpu(cpu) { pevent = per_cpu_ptr(cpu_events, cpu); - bp = perf_event_create_kernel_counter(attr, cpu, -1, triggered); + bp = perf_event_create_kernel_counter(attr, cpu, NULL, triggered); *pevent = bp; |
