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Re: [PATCH] Fix length calculation in aarch64_linux_set_debug_regs
- From: Simon Marchi <simon dot marchi at ericsson dot com>
- To: Yao Qi <qiyaoltc at gmail dot com>
- Cc: <gdb-patches at sourceware dot org>
- Date: Thu, 19 Nov 2015 10:20:27 -0500
- Subject: Re: [PATCH] Fix length calculation in aarch64_linux_set_debug_regs
- Authentication-results: sourceware.org; auth=none
- References: <1446475684-31936-1-git-send-email-simon dot marchi at ericsson dot com> <8637w21a14 dot fsf at gmail dot com> <564DCF6B dot 9030302 at ericsson dot com> <564DD3BE dot 2080305 at gmail dot com>
On 15-11-19 08:50 AM, Yao Qi wrote:
> You can push it in, with some commit log adjustments, because the old
> code is correct.
Ok I pushed it. Again, sorry for saying the code was not correct :).
From bb82e93484cdd56c67efd52b869a6123b2623f6c Mon Sep 17 00:00:00 2001
From: Simon Marchi <simon.marchi@ericsson.com>
Date: Thu, 19 Nov 2015 10:17:36 -0500
Subject: [PATCH] Fix iov_len calculation in aarch64_linux_set_debug_regs
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There is this build failure when building in C++:
/home/simark/src/binutils-gdb/gdb/nat/aarch64-linux-hw-point.c: In function ÃâËvoid aarch64_linux_set_debug_regs(const aarch64_debug_reg_state*, int, int)Ãââ:
/home/simark/src/binutils-gdb/gdb/nat/aarch64-linux-hw-point.c:564:64: error: ÃâËcountÃââ cannot appear in a constant-expression
iov.iov_len = (offsetof (struct user_hwdebug_state, dbg_regs[count - 1])
^
We can simplify the computation and make g++ happy at the same time by
formulating as:
size of fixed part + size of variable part
thus...
size of fixed part + count * size of one variable part element
thus...
offsetof (struct user_hwdebug_state, dbg_regs) + count * sizeof (regs.dbg_reg[0]);
gdb/ChangeLog:
* nat/aarch64-linux-hw-point.c (aarch64_linux_set_debug_regs): Change
form of iov_len computation.
---
gdb/ChangeLog | 5 +++++
gdb/nat/aarch64-linux-hw-point.c | 4 ++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0539d96..94721a0 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2015-11-19 Simon Marchi <simon.marchi@ericsson.com>
+
+ * nat/aarch64-linux-hw-point.c (aarch64_linux_set_debug_regs): Change
+ form of iov_len computation.
+
2015-11-19 Pedro Alves <palves@redhat.com>
* configure.ac (ERROR_ON_WARNING): Don't check whether in C++
diff --git a/gdb/nat/aarch64-linux-hw-point.c b/gdb/nat/aarch64-linux-hw-point.c
index 1a5fa6a..dcbfa98 100644
--- a/gdb/nat/aarch64-linux-hw-point.c
+++ b/gdb/nat/aarch64-linux-hw-point.c
@@ -561,8 +561,8 @@ aarch64_linux_set_debug_regs (const struct aarch64_debug_reg_state *state,
ctrl = watchpoint ? state->dr_ctrl_wp : state->dr_ctrl_bp;
if (count == 0)
return;
- iov.iov_len = (offsetof (struct user_hwdebug_state, dbg_regs[count - 1])
- + sizeof (regs.dbg_regs [count - 1]));
+ iov.iov_len = (offsetof (struct user_hwdebug_state, dbg_regs)
+ + count * sizeof (regs.dbg_regs[0]));
for (i = 0; i < count; i++)
{
--
2.5.1