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| author | Oleg Nesterov <oleg@redhat.com> | 2013-07-08 16:01:01 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-09 10:33:26 -0700 |
| commit | b87a95ad609619482df0690320d5ace33ace8e7a (patch) | |
| tree | 8b82e73b6daa22d4cfeac8d217401906502c1c6f | |
| parent | 9afe33ada275f2413dfeae27cc58fbb27474ac72 (diff) | |
| download | linux-stable-b87a95ad609619482df0690320d5ace33ace8e7a.tar.gz linux-stable-b87a95ad609619482df0690320d5ace33ace8e7a.tar.bz2 linux-stable-b87a95ad609619482df0690320d5ace33ace8e7a.zip | |
ptrace/x86: ptrace_write_dr7() should create bp if !disabled
Commit 24f1e32c60c4 ("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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -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); |