diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-09-02 16:25:54 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-09-04 16:12:52 +0300 |
| commit | 7043679a989af969e9f20cc7d90195b36f54036f (patch) | |
| tree | 972e29a383969e91dd24be89f4c7b7bbb49e01bb /arch | |
| parent | 20a6e35a948284b8ab246ed35eefc56d674ad076 (diff) | |
| download | linux-7043679a989af969e9f20cc7d90195b36f54036f.tar.xz | |
x86/debug: Remove handle_debug(.user) argument
The handle_debug(.user) argument is used to terminate the #DB handler early
for the INT1-from-kernel case, since the kernel doesn't use INT1.
Remove the argument and handle this explicitly in #DB-from-kernel.
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>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200902133200.907020598@infradead.org
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/traps.c | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 9cb39d30413d..58bc434c75de 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -783,25 +783,18 @@ static __always_inline unsigned long debug_read_clear_dr6(void) * * May run on IST stack. */ -static void handle_debug(struct pt_regs *regs, unsigned long dr6, bool user) +static void handle_debug(struct pt_regs *regs, unsigned long dr6) { struct task_struct *tsk = current; bool user_icebp; int si_code; /* - * If DR6 is zero, no point in trying to handle it. The kernel is - * not using INT1. - */ - if (!user && !dr6) - return; - - /* * If dr6 has no reason to give us about the origin of this trap, * then it's very likely the result of an icebp/int01 trap. * User wants a sigtrap for that. */ - user_icebp = user && !dr6; + user_icebp = !dr6; /* Store the virtualized DR6 value */ tsk->thread.debugreg6 = dr6; @@ -874,7 +867,13 @@ static __always_inline void exc_debug_kernel(struct pt_regs *regs, if (kprobe_debug_handler(regs)) goto out; - handle_debug(regs, dr6, false); + /* + * The kernel doesn't use INT1 + */ + if (!dr6) + goto out; + + handle_debug(regs, dr6); out: instrumentation_end(); @@ -904,7 +903,7 @@ static __always_inline void exc_debug_user(struct pt_regs *regs, irqentry_enter_from_user_mode(regs); instrumentation_begin(); - handle_debug(regs, dr6, true); + handle_debug(regs, dr6); instrumentation_end(); irqentry_exit_to_user_mode(regs); |