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[Qemu-devel] [PATCH] linux-user: Handle new ARM breakpoint instruction
From: |
Hunter Laux |
Subject: |
[Qemu-devel] [PATCH] linux-user: Handle new ARM breakpoint instruction |
Date: |
Tue, 24 Jun 2014 21:08:57 -0700 |
This instruction space is guaranteed to be undefined.
ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
Thumb: 1101 1110 xxxx xxxx
The breakpoint instructions were selected from this instruction space.
Linux traps the illegal instruction and sends a SIGTRAP if it is a breakpoint.
Here is the Linux implementation:
http://lxr.free-electrons.com/source/arch/arm/kernel/ptrace.c#L221
Signed-off-by: Hunter Laux <address@hidden>
---
linux-user/main.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/linux-user/main.c b/linux-user/main.c
index 900a17f..91f2681 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -688,11 +688,29 @@ void cpu_loop(CPUARMState *env)
uint32_t opcode;
int rc;
+ const uint32_t arm_bkpt_mask = 0x0FFFFFFF;
+ const uint32_t arm_bkpt = 0x07F001F0;
+ const uint32_t arm_bkpt_thumb_mask = 0x0000FFFF;
+ const uint32_t arm_bkpt_thumb = 0x0000DE01;
+ const uint32_t arm_bkpt_thumb2_mask = 0xFFFFFFFF;
+ const uint32_t arm_bkpt_thumb2 = 0xF7F0A000;
+
/* we handle the FPU emulation here, as Linux */
/* we get the opcode */
/* FIXME - what to do if get_user() fails? */
get_user_code_u32(opcode, env->regs[15], env->bswap_code);
+ if (env->thumb) {
+ if ((opcode & arm_bkpt_thumb_mask) == arm_bkpt_thumb
+ || (opcode & arm_bkpt_thumb2_mask) == arm_bkpt_thumb2)
{
+ goto excp_debug;
+ }
+ } else {
+ if ((opcode & arm_bkpt_mask) == arm_bkpt) {
+ goto excp_debug;
+ }
+ }
+
rc = EmulateAll(opcode, &ts->fpa, env);
if (rc == 0) { /* illegal instruction */
info.si_signo = SIGILL;
--
1.9.1
- [Qemu-devel] [PATCH] linux-user: Handle new ARM breakpoint instruction,
Hunter Laux <=