From patchwork Thu May 19 18:04:39 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [11/71] hw_breakpoints, powerpc: Fix CONFIG_HAVE_HW_BREAKPOINT off-case in ptrace_set_debugreg() Date: Thu, 19 May 2011 08:04:39 -0000 From: gregkh@suse.de X-Patchwork-Id: 96441 Message-Id: <20110519180555.352937123@clark.kroah.org> To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Frederic Weisbecker , Ingo Molnar , torvalds@linux-foundation.org, Prasad , akpm@linux-foundation.org, LPPC , stable-review@kernel.org, alan@lxorguk.ukuu.org.uk 2.6.38-stable review patch. If anyone has any objections, please let us know. ------------------ From: Frederic Weisbecker commit 925f83c085e1bb08435556c5b4844a60de002e31 upstream. We make use of ptrace_get_breakpoints() / ptrace_put_breakpoints() to protect ptrace_set_debugreg() even if CONFIG_HAVE_HW_BREAKPOINT if off. However in this case, these APIs are not implemented. To fix this, push the protection down inside the relevant ifdef. Best would be to export the code inside CONFIG_HAVE_HW_BREAKPOINT into a standalone function to cleanup the ifdefury there and call the breakpoint ref API inside. But as it is more invasive, this should be rather made in an -rc1. Fixes this build error: arch/powerpc/kernel/ptrace.c:1594: error: implicit declaration of function 'ptrace_get_breakpoints' make[2]: *** Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Cc: LPPC Cc: Prasad Link: http://lkml.kernel.org/r/1304639598-4707-1-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/ptrace.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -924,12 +924,16 @@ int ptrace_set_debugreg(struct task_stru if (data && !(data & DABR_TRANSLATION)) return -EIO; #ifdef CONFIG_HAVE_HW_BREAKPOINT + if (ptrace_get_breakpoints(task) < 0) + return -ESRCH; + bp = thread->ptrace_bps[0]; if ((!data) || !(data & (DABR_DATA_WRITE | DABR_DATA_READ))) { if (bp) { unregister_hw_breakpoint(bp); thread->ptrace_bps[0] = NULL; } + ptrace_put_breakpoints(task); return 0; } if (bp) { @@ -939,9 +943,12 @@ int ptrace_set_debugreg(struct task_stru (DABR_DATA_WRITE | DABR_DATA_READ), &attr.bp_type); ret = modify_user_hw_breakpoint(bp, &attr); - if (ret) + if (ret) { + ptrace_put_breakpoints(task); return ret; + } thread->ptrace_bps[0] = bp; + ptrace_put_breakpoints(task); thread->dabr = data; return 0; } @@ -956,9 +963,12 @@ int ptrace_set_debugreg(struct task_stru ptrace_triggered, task); if (IS_ERR(bp)) { thread->ptrace_bps[0] = NULL; + ptrace_put_breakpoints(task); return PTR_ERR(bp); } + ptrace_put_breakpoints(task); + #endif /* CONFIG_HAVE_HW_BREAKPOINT */ /* Move contents to the DABR register */