diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-05-29 23:27:33 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:15:21 +0200 |
| commit | e1de11d4d1a64ac1b90b9833f1a3629dae18facb (patch) | |
| tree | 0018983a29a3b2b285805eefe8151a9ca335698c /arch/x86/kernel/traps.c | |
| parent | x86/hw_breakpoint: Prevent data breakpoints on user_pcid_flush_mask (diff) | |
| download | linux-e1de11d4d1a64ac1b90b9833f1a3629dae18facb.tar.xz linux-e1de11d4d1a64ac1b90b9833f1a3629dae18facb.zip | |
x86/entry: Introduce local_db_{save,restore}()
In order to allow other exceptions than #DB to disable breakpoints,
provide common helpers.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200529213321.012060983@infradead.org
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/traps.c | 18 |
1 files changed, 2 insertions, 16 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 50fb9cd5be97..bcb9dd961c6d 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -727,15 +727,7 @@ static __always_inline void debug_enter(unsigned long *dr6, unsigned long *dr7) * Entry text is excluded for HW_BP_X and cpu_entry_area, which * includes the entry stack is excluded for everything. */ - get_debugreg(*dr7, 7); - set_debugreg(0, 7); - - /* - * Ensure the compiler doesn't lower the above statements into - * the critical section; disabling breakpoints late would not - * be good. - */ - barrier(); + *dr7 = local_db_save(); /* * The Intel SDM says: @@ -756,13 +748,7 @@ static __always_inline void debug_enter(unsigned long *dr6, unsigned long *dr7) static __always_inline void debug_exit(unsigned long dr7) { - /* - * Ensure the compiler doesn't raise this statement into - * the critical section; enabling breakpoints early would - * not be good. - */ - barrier(); - set_debugreg(dr7, 7); + local_db_restore(dr7); } /* |