diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2013-06-07 10:09:36 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-06-17 18:20:18 +1000 |
| commit | 8f4a5b9369009e75bb8b43909a4f25f0fe2c13fd (patch) | |
| tree | b9aed20e0805c839d503230813a17c5cbd769d46 /arch | |
| parent | dd164d73437e080b9d793137a05e4cef8c066be9 (diff) | |
ptrace/x86: ptrace_write_dr7() should create bp if !disabled
24f1e32c ("hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf
events") introduced the minor regression. Before this commit
PTRACE_POKEUSER DR7, enableDR0
PTRACE_POKEUSER DR0, address
was perfectly valid, now PTRACE_POKEUSER(DR7) fails if DR0 was not
previously initialized by PTRACE_POKEUSER(DR0).
Change ptrace_write_dr7() to do ptrace_register_breakpoint(addr => 0) if
!bp && !disabled. This fixes watchpoint-zeroaddr from ptrace-tests, see
https://bugzilla.redhat.com/show_bug.cgi?id=660204.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@kernel.org>
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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 052636801b41..5c387b3dce3f 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -670,13 +670,16 @@ restore: if (!bp) { if (disabled) continue; - /* - * We should have at least an inactive breakpoint at - * this slot. It means the user is writing dr7 without - * having written the address register first. - */ - rc = -EINVAL; - break; + + bp = ptrace_register_breakpoint(tsk, + len, type, 0, disabled); + if (IS_ERR(bp)) { + rc = PTR_ERR(bp); + break; + } + + thread->ptrace_bps[i] = bp; + continue; } rc = ptrace_modify_breakpoint(bp, len, type, disabled); |