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| author | Oleg Nesterov <oleg@redhat.com> | 2013-07-09 01:01:06 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-09 19:33:26 +0200 |
| commit | f7da04c9e363e479258135ac825734d78aecd2b0 (patch) | |
| tree | 32cbf157b2a451b559eb71f7791c9b98af044f52 /arch/x86/kernel/hw_breakpoint.c | |
| parent | ptrace: PTRACE_DETACH should do flush_ptrace_hw_breakpoint(child) (diff) | |
| download | linux-f7da04c9e363e479258135ac825734d78aecd2b0.tar.xz linux-f7da04c9e363e479258135ac825734d78aecd2b0.zip | |
ptrace/x86: flush_ptrace_hw_breakpoint() shoule clear the virtual debug registers
flush_ptrace_hw_breakpoint() destroys the counters set by ptrace, but
"leaks" ->debugreg6 and ->ptrace_dr7.
The problem is minor, but still it doesn't look right and flush_thread()
did this until commit 66cb59172959 ("hw-breakpoints: use the new wrapper
routines to access debug registers in process/thread code"). Now that
PTRACE_DETACH does flush_ too this makes even more sense.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/hw_breakpoint.c')
| -rw-r--r-- | arch/x86/kernel/hw_breakpoint.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index 02f07634d265..f66ff162dce8 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -393,6 +393,9 @@ void flush_ptrace_hw_breakpoint(struct task_struct *tsk) unregister_hw_breakpoint(t->ptrace_bps[i]); t->ptrace_bps[i] = NULL; } + + t->debugreg6 = 0; + t->ptrace_dr7 = 0; } void hw_breakpoint_restore(void) |