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| author | K.Prasad <prasad@linux.vnet.ibm.com> | 2009-06-01 23:47:06 +0530 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-06-02 22:47:00 +0200 |
| commit | 62edab9056a6cf0c9207339c8892c923a5217e45 (patch) | |
| tree | 2becd775fdc2a25df3daacf69d80685b251fbed9 /arch/x86/kernel/kprobes.c | |
| parent | 0722db015c246204044299eae3b02d18d3ca4faf (diff) | |
| download | lwn-62edab9056a6cf0c9207339c8892c923a5217e45.tar.gz lwn-62edab9056a6cf0c9207339c8892c923a5217e45.zip | |
hw-breakpoints: reset bits in dr6 after the corresponding exception is handled
This patch resets the bit in dr6 after the corresponding exception is
handled in code, so that we keep a clean track of the current virtual debug
status register.
[ Impact: keep track of breakpoints triggering completion ]
Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'arch/x86/kernel/kprobes.c')
| -rw-r--r-- | arch/x86/kernel/kprobes.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index 7b5169d2b000..b5b1848c5336 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -54,6 +54,7 @@ #include <asm/pgtable.h> #include <asm/uaccess.h> #include <asm/alternative.h> +#include <asm/debugreg.h> void jprobe_return_end(void); @@ -967,8 +968,14 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, ret = NOTIFY_STOP; break; case DIE_DEBUG: - if (post_kprobe_handler(args->regs)) + if (post_kprobe_handler(args->regs)) { + /* + * Reset the BS bit in dr6 (pointed by args->err) to + * denote completion of processing + */ + (*(unsigned long *)ERR_PTR(args->err)) &= ~DR_STEP; ret = NOTIFY_STOP; + } break; case DIE_GPF: /* |