From c7aa00db074e4961b49277d7d0fc2f5367d914ca Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Thu, 19 Jul 2012 17:49:22 +0100
Subject: [PATCH] ARM: 7475/1: sys_trace: allow all syscall arguments to be
updated via ptrace
Prior to syscall invocation, __sys_trace only reloads r0-r3 from the
kernel stack, preventing the debugger from updating arguments 5-7 when
signalled via ptrace.
This patch updates the code to reload r0-r6, updating arguments 5 and 6
on the stack (argument 7 is only used by OABI indirect syscalls and
can remain in a register).
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/kernel/entry-common.S | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 2909bbcaa0d119..978eac57e04a78 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -443,7 +443,8 @@ __sys_trace:
mov scno, r0 @ syscall number (possibly new)
add r1, sp, #S_R0 + S_OFF @ pointer to regs
cmp scno, #NR_syscalls @ check upper syscall limit
- ldmccia r1, {r0 - r3} @ have to reload r0 - r3
+ ldmccia r1, {r0 - r6} @ have to reload r0 - r6
+ stmccia sp, {r4, r5} @ and update the stack args
ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
b 2b
--
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