diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-09-02 15:26:02 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-09-04 15:12:58 +0200 |
| commit | d53d9bc0cf783e93b374de3895145c7375e570ba (patch) | |
| tree | fb95a9c74cba7e6a7d93f58f80f542e941f99997 /arch/x86/kernel/kgdb.c | |
| parent | x86/debug: Support negative polarity DR6 bits (diff) | |
| download | linux-d53d9bc0cf783e93b374de3895145c7375e570ba.tar.xz linux-d53d9bc0cf783e93b374de3895145c7375e570ba.zip | |
x86/debug: Change thread.debugreg6 to thread.virtual_dr6
Current usage of thread.debugreg6 is convoluted at best. It starts life as
a copy of the hardware DR6 value, but then various bits are cleared and
set.
Replace this with a new variable thread.virtual_dr6 that is initialized to
0 when DR6 is read and only gains bits, at the same time the actual (on
stack) dr6 value which is read from the hardware only gets bits cleared.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200902133201.415372940@infradead.org
Diffstat (limited to 'arch/x86/kernel/kgdb.c')
| -rw-r--r-- | arch/x86/kernel/kgdb.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index c2f02f308ecf..ff7878df96b4 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -629,9 +629,10 @@ static void kgdb_hw_overflow_handler(struct perf_event *event, struct task_struct *tsk = current; int i; - for (i = 0; i < 4; i++) + for (i = 0; i < 4; i++) { if (breakinfo[i].enabled) - tsk->thread.debugreg6 |= (DR_TRAP0 << i); + tsk->thread.virtual_dr6 |= (DR_TRAP0 << i); + } } void kgdb_arch_late(void) |