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authorIngo Molnar <mingo@kernel.org>2021-02-12 14:54:51 +0300
committerIngo Molnar <mingo@kernel.org>2021-02-12 14:54:58 +0300
commit62137364e3e8afcc745846c5c67cacf943149073 (patch)
tree42f2bdee6b16e383b6e0a94cb3abc62f335d721a /arch/x86/kernel/step.c
parent6c80408a8a0360fa9223b8c21c0ab8ef42e88bfe (diff)
parentdcc0b49040c70ad827a7f3d58a21b01fdb14e749 (diff)
downloadlinux-62137364e3e8afcc745846c5c67cacf943149073.tar.xz
Merge branch 'linus' into locking/core, to pick up upstream fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/step.c')
-rw-r--r--arch/x86/kernel/step.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index 60d2c3798ba2..0f3c307b37b3 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -127,12 +127,17 @@ static int enable_single_step(struct task_struct *child)
regs->flags |= X86_EFLAGS_TF;
/*
- * Always set TIF_SINGLESTEP - this guarantees that
- * we single-step system calls etc.. This will also
+ * Always set TIF_SINGLESTEP. This will also
* cause us to set TF when returning to user mode.
*/
set_tsk_thread_flag(child, TIF_SINGLESTEP);
+ /*
+ * Ensure that a trap is triggered once stepping out of a system
+ * call prior to executing any user instruction.
+ */
+ set_task_syscall_work(child, SYSCALL_EXIT_TRAP);
+
oflags = regs->flags;
/* Set TF on the kernel stack.. */
@@ -230,6 +235,7 @@ void user_disable_single_step(struct task_struct *child)
/* Always clear TIF_SINGLESTEP... */
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+ clear_task_syscall_work(child, SYSCALL_EXIT_TRAP);
/* But touch TF only if it was set by us.. */
if (test_and_clear_tsk_thread_flag(child, TIF_FORCED_TF))