diff options
| author | Martin Schwidefsky | 2018-04-20 10:21:21 +0200 |
|---|---|---|
| committer | Martin Schwidefsky | 2018-04-23 07:57:17 +0200 |
| commit | 2317b07d05d2b136eb4dc9609807c9111bda3b2a (patch) | |
| tree | b4290d962400d850031b1890568ef00a7f3fe9ab /arch/s390 | |
| parent | 5f3ba878e7a2ffef82fb0882c0dd2c3507d734bc (diff) | |
s390: update sampling tag after task pid change
In a multi-threaded program any thread can call execve(). If this
is not done by the thread group leader, the de_thread() function
replaces the pid of the task that calls execve() with the pid of
thread group leader. If the task reaches user space again without
going over __switch_to() the sampling tag is still set to the old
pid.
Define the arch_setup_new_exec function to verify the task pid
and udpate the tag with LPP if it has changed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/thread_info.h | 3 | ||||
| -rw-r--r-- | arch/s390/kernel/process.c | 10 |
2 files changed, 13 insertions, 0 deletions
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h index 83ba57533ce6..3c883c368eb0 100644 --- a/arch/s390/include/asm/thread_info.h +++ b/arch/s390/include/asm/thread_info.h @@ -45,6 +45,9 @@ struct thread_info { void arch_release_task_struct(struct task_struct *tsk); int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); +void arch_setup_new_exec(void); +#define arch_setup_new_exec arch_setup_new_exec + #endif /* diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 70576a2f69cf..6e758bb6cd29 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -29,6 +29,7 @@ #include <linux/random.h> #include <linux/export.h> #include <linux/init_task.h> +#include <asm/cpu_mf.h> #include <asm/io.h> #include <asm/processor.h> #include <asm/vtimer.h> @@ -48,6 +49,15 @@ void flush_thread(void) { } +void arch_setup_new_exec(void) +{ + if (S390_lowcore.current_pid != current->pid) { + S390_lowcore.current_pid = current->pid; + if (test_facility(40)) + lpp(&S390_lowcore.lpp); + } +} + void arch_release_task_struct(struct task_struct *tsk) { runtime_instr_release(tsk); |