s390: update sampling tag after task pid change (2317b07d) · Commits · 戴 / test

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>

arch/s390/include/asm/thread_info.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -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

		/*

arch/s390/kernel/process.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -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);

Admin message