entry: Unbreak single step reporting behaviour
authorYuxuan Shui <yshuiv7@gmail.com>
Sat, 23 Jan 2021 11:21:32 +0000 (03:21 -0800)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 28 Jan 2021 12:46:55 +0000 (13:46 +0100)
The move of TIF_SYSCALL_EMU to SYSCALL_WORK_SYSCALL_EMU broke single step
reporting. The original code reported the single step when TIF_SINGLESTEP
was set and TIF_SYSCALL_EMU was not set. The SYSCALL_WORK conversion got
the logic wrong and now the reporting only happens when both bits are set.

Restore the original behaviour.

[ tglx: Massaged changelog and dropped the pointless double negation ]

Fixes: 64eb35f701f0 ("ptrace: Migrate TIF_SYSCALL_EMU to use SYSCALL_WORK flag")
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Link: https://lore.kernel.org/r/877do3gaq9.fsf@m5Zedd9JOGzJrf0
kernel/entry/common.c

index 3783416..6dd82be 100644 (file)
@@ -222,7 +222,7 @@ static inline bool report_single_step(unsigned long work)
  */
 static inline bool report_single_step(unsigned long work)
 {
-       if (!(work & SYSCALL_WORK_SYSCALL_EMU))
+       if (work & SYSCALL_WORK_SYSCALL_EMU)
                return false;
 
        return !!(current_thread_info()->flags & _TIF_SINGLESTEP);