From: Oleg Nesterov <oleg@redhat.com>
To: Michael Neuling <mikey@neuling.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH] ptrace/powerpc: dont flush_ptrace_hw_breakpoint() on fork()
Date: Sun, 21 Apr 2013 18:47:59 +0200 [thread overview]
Message-ID: <20130421164759.GA5537@redhat.com> (raw)
arch_dup_task_struct() does flush_ptrace_hw_breakpoint(src), this
destroys the parent's breakpoints for no reason. We should clear
child->thread.ptrace_bps[] copied by dup_task_struct() instead.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michael Neuling <mikey@neuling.org>
--- x/arch/powerpc/kernel/process.c
+++ x/arch/powerpc/kernel/process.c
@@ -910,10 +910,6 @@ int arch_dup_task_struct(struct task_str
flush_altivec_to_thread(src);
flush_vsx_to_thread(src);
flush_spe_to_thread(src);
-#ifdef CONFIG_HAVE_HW_BREAKPOINT
- flush_ptrace_hw_breakpoint(src);
-#endif /* CONFIG_HAVE_HW_BREAKPOINT */
-
*dst = *src;
return 0;
}
@@ -984,6 +980,10 @@ int copy_thread(unsigned long clone_flag
p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
_ALIGN_UP(sizeof(struct thread_info), 16);
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ p->thread.ptrace_bps[0] = NULL;
+#endif
+
#ifdef CONFIG_PPC_STD_MMU_64
if (mmu_has_feature(MMU_FTR_SLB)) {
unsigned long sp_vsid;
reply other threads:[~2013-04-21 16:50 UTC|newest]
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