Thread (21 messages) flat view 21 messages, 3 authors, 2011-12-08

Re: [PATCH 2/2] [PowerPC Book3E] Introduce new ptrace debug feature flag

From: David Gibson <hidden>
Date: 2011-08-23 05:09:36

On Fri, Aug 19, 2011 at 01:23:38PM +0530, K.Prasad wrote:
While PPC_PTRACE_SETHWDEBUG ptrace flag in PowerPC accepts
PPC_BREAKPOINT_MODE_EXACT mode of breakpoint, the same is not intimated to the
user-space debuggers (like GDB) who may want to use it. Hence we introduce a
new PPC_DEBUG_FEATURE_DATA_BP_EXACT flag which will be populated on the
"features" member of "struct ppc_debug_info" to advertise support for the
same on Book3E PowerPC processors.
I thought the idea was that the BP_EXACT mode was the default - if the
new interface was supported at all, then BP_EXACT was always
supported.  So, why do you need a new flag?
quoted hunk ↗ jump to hunk
Signed-off-by: K.Prasad <redacted>
---
 arch/powerpc/include/asm/ptrace.h |    1 +
 arch/powerpc/kernel/ptrace.c      |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 48223f9..cf014f9 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -380,6 +380,7 @@ struct ppc_debug_info {
 #define PPC_DEBUG_FEATURE_INSN_BP_MASK		0x0000000000000002
 #define PPC_DEBUG_FEATURE_DATA_BP_RANGE		0x0000000000000004
 #define PPC_DEBUG_FEATURE_DATA_BP_MASK		0x0000000000000008
+#define PPC_DEBUG_FEATURE_DATA_BP_EXACT		0x0000000000000010
 
 #ifndef __ASSEMBLY__
 
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 18d28b6..71db5a6 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1636,6 +1636,7 @@ long arch_ptrace(struct task_struct *child, long request,
 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
 		dbginfo.features |=
 				   PPC_DEBUG_FEATURE_DATA_BP_RANGE |
+				   PPC_DEBUG_FEATURE_DATA_BP_EXACT |
 				   PPC_DEBUG_FEATURE_DATA_BP_MASK;
 #endif
 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */
-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson
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