* [Qemu-devel] [PATCH] linux-user: Fix MIPS N64 trap and break instruction bug
@ 2015-06-29 10:20 Andrew Bennett
2015-06-30 13:18 ` Leon Alrae
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Bennett @ 2015-06-29 10:20 UTC (permalink / raw)
To: qemu-devel; +Cc: Riku Voipio, Leon Alrae
From: Andrew Bennett <andrew.bennett@imgtec.com>
For the MIPS N64 ABI when QEMU reads the break/trap instruction so that
it can inspect the break/trap code it reads 8 rather than 4 bytes
which means it finds the code field from the instruction after the
break/trap instruction. This then causes the break/trap handling
code to fail because it does not understand the code number.
The fix forces QEMU to always read 4 bytes of instruction data rather
than deciding how much to read based on the ABI.
Signed-off-by: Andrew Bennett <andrew.bennett@imgtec.com>
---
linux-user/main.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/linux-user/main.c b/linux-user/main.c
index c855bcc..2f8f3e6 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -2578,7 +2578,7 @@ done_syscall:
code = (trap_instr >> 6) & 0x3f;
}
} else {
- ret = get_user_ual(trap_instr, env->active_tc.PC);
+ ret = get_user_u32(trap_instr, env->active_tc.PC);
if (ret != 0) {
goto error;
}
@@ -2612,7 +2612,7 @@ done_syscall:
trap_instr = (instr[0] << 16) | instr[1];
} else {
- ret = get_user_ual(trap_instr, env->active_tc.PC);
+ ret = get_user_u32(trap_instr, env->active_tc.PC);
}
if (ret != 0) {
--
1.7.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH] linux-user: Fix MIPS N64 trap and break instruction bug
2015-06-29 10:20 [Qemu-devel] [PATCH] linux-user: Fix MIPS N64 trap and break instruction bug Andrew Bennett
@ 2015-06-30 13:18 ` Leon Alrae
2015-07-15 15:54 ` Leon Alrae
0 siblings, 1 reply; 3+ messages in thread
From: Leon Alrae @ 2015-06-30 13:18 UTC (permalink / raw)
To: Andrew Bennett, qemu-devel; +Cc: Riku Voipio
On 29/06/2015 11:20, Andrew Bennett wrote:
> From: Andrew Bennett <andrew.bennett@imgtec.com>
>
> For the MIPS N64 ABI when QEMU reads the break/trap instruction so that
> it can inspect the break/trap code it reads 8 rather than 4 bytes
> which means it finds the code field from the instruction after the
> break/trap instruction. This then causes the break/trap handling
> code to fail because it does not understand the code number.
>
> The fix forces QEMU to always read 4 bytes of instruction data rather
> than deciding how much to read based on the ABI.
>
> Signed-off-by: Andrew Bennett <andrew.bennett@imgtec.com>
> ---
> linux-user/main.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Thanks,
Leon
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH] linux-user: Fix MIPS N64 trap and break instruction bug
2015-06-30 13:18 ` Leon Alrae
@ 2015-07-15 15:54 ` Leon Alrae
0 siblings, 0 replies; 3+ messages in thread
From: Leon Alrae @ 2015-07-15 15:54 UTC (permalink / raw)
To: Andrew Bennett, qemu-devel; +Cc: Riku Voipio
On 30/06/2015 14:18, Leon Alrae wrote:
> On 29/06/2015 11:20, Andrew Bennett wrote:
>> From: Andrew Bennett <andrew.bennett@imgtec.com>
>>
>> For the MIPS N64 ABI when QEMU reads the break/trap instruction so that
>> it can inspect the break/trap code it reads 8 rather than 4 bytes
>> which means it finds the code field from the instruction after the
>> break/trap instruction. This then causes the break/trap handling
>> code to fail because it does not understand the code number.
>>
>> The fix forces QEMU to always read 4 bytes of instruction data rather
>> than deciding how much to read based on the ABI.
>>
>> Signed-off-by: Andrew Bennett <andrew.bennett@imgtec.com>
>> ---
>> linux-user/main.c | 4 ++--
>> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Riku, I'm including this patch in target-mips queue which I'm going to send
out soon for rc1. If you have any objections please let me know.
Thanks,
Leon
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-06-29 10:20 [Qemu-devel] [PATCH] linux-user: Fix MIPS N64 trap and break instruction bug Andrew Bennett
2015-06-30 13:18 ` Leon Alrae
2015-07-15 15:54 ` Leon Alrae
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