* [PATCH v2 0/2] target/m68k: Reject immediate as destination
@ 2023-03-09 20:16 Richard Henderson
2023-03-09 20:16 ` [PATCH v2 1/2] target/m68k: Reject immediate as destination in gen_ea_mode Richard Henderson
2023-03-09 20:16 ` [PATCH v2 2/2] linux-user/m68k: Handle EXCP_ADDRESS in cpu_loop Richard Henderson
0 siblings, 2 replies; 7+ messages in thread
From: Richard Henderson @ 2023-03-09 20:16 UTC (permalink / raw)
To: qemu-devel; +Cc: laurent
The translate.c fix is extracted from a larger patch set.
I then add a test case and fix cpu_loop to raise the proper signal.
r~
Richard Henderson (2):
target/m68k: Reject immediate as destination in gen_ea_mode
linux-user/m68k: Handle EXCP_ADDRESS in cpu_loop
linux-user/m68k/cpu_loop.c | 5 ++++-
target/m68k/translate.c | 4 ++++
tests/tcg/m68k/excp-address.c | 32 ++++++++++++++++++++++++++++++++
tests/tcg/m68k/Makefile.target | 1 +
4 files changed, 41 insertions(+), 1 deletion(-)
create mode 100644 tests/tcg/m68k/excp-address.c
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2 1/2] target/m68k: Reject immediate as destination in gen_ea_mode
2023-03-09 20:16 [PATCH v2 0/2] target/m68k: Reject immediate as destination Richard Henderson
@ 2023-03-09 20:16 ` Richard Henderson
2023-03-10 10:03 ` Laurent Vivier
2023-03-15 16:41 ` Laurent Vivier
2023-03-09 20:16 ` [PATCH v2 2/2] linux-user/m68k: Handle EXCP_ADDRESS in cpu_loop Richard Henderson
1 sibling, 2 replies; 7+ messages in thread
From: Richard Henderson @ 2023-03-09 20:16 UTC (permalink / raw)
To: qemu-devel; +Cc: laurent
In theory this should never happen, as all such instructions
are illegal. This is checked in e.g. gen_lea_mode and
gen_ea_mode_fp but not here. In case something higher up
isn't checking modes properly, return NULL_QREG. This will
result in an illegal instruction exception being raised.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/m68k/translate.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 422f4652f1..e16c608ef8 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -894,6 +894,10 @@ static TCGv gen_ea_mode(CPUM68KState *env, DisasContext *s, int mode, int reg0,
case 3: /* pc index+displacement. */
goto do_indirect;
case 4: /* Immediate. */
+ /* Should never be used for an output or RMW input. */
+ if (what == EA_STORE || addrp) {
+ return NULL_QREG;
+ }
/* Sign extend values for consistency. */
switch (opsize) {
case OS_BYTE:
--
2.34.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 2/2] linux-user/m68k: Handle EXCP_ADDRESS in cpu_loop
2023-03-09 20:16 [PATCH v2 0/2] target/m68k: Reject immediate as destination Richard Henderson
2023-03-09 20:16 ` [PATCH v2 1/2] target/m68k: Reject immediate as destination in gen_ea_mode Richard Henderson
@ 2023-03-09 20:16 ` Richard Henderson
2023-03-15 18:16 ` Laurent Vivier
1 sibling, 1 reply; 7+ messages in thread
From: Richard Henderson @ 2023-03-09 20:16 UTC (permalink / raw)
To: qemu-devel; +Cc: laurent
This exception can be raised by illegal instructions.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/m68k/cpu_loop.c | 5 ++++-
tests/tcg/m68k/excp-address.c | 32 ++++++++++++++++++++++++++++++++
tests/tcg/m68k/Makefile.target | 1 +
3 files changed, 37 insertions(+), 1 deletion(-)
create mode 100644 tests/tcg/m68k/excp-address.c
diff --git a/linux-user/m68k/cpu_loop.c b/linux-user/m68k/cpu_loop.c
index caead1cb74..84b5d290c0 100644
--- a/linux-user/m68k/cpu_loop.c
+++ b/linux-user/m68k/cpu_loop.c
@@ -35,7 +35,10 @@ void cpu_loop(CPUM68KState *env)
cpu_exec_end(cs);
process_queued_cpu_work(cs);
- switch(trapnr) {
+ switch (trapnr) {
+ case EXCP_ADDRESS:
+ force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, env->pc);
+ break;
case EXCP_ILLEGAL:
case EXCP_LINEA:
case EXCP_LINEF:
diff --git a/tests/tcg/m68k/excp-address.c b/tests/tcg/m68k/excp-address.c
new file mode 100644
index 0000000000..1dbdddef58
--- /dev/null
+++ b/tests/tcg/m68k/excp-address.c
@@ -0,0 +1,32 @@
+/*
+ * Test m68k address exception
+ */
+
+#define _GNU_SOURCE 1
+#include <signal.h>
+#include <stdlib.h>
+
+static void sig_handler(int sig, siginfo_t *si, void *puc)
+{
+ exit(0);
+}
+
+int main(int argc, char **argv)
+{
+ struct sigaction act = {
+ .sa_sigaction = sig_handler,
+ .sa_flags = SA_SIGINFO
+ };
+
+ sigaction(SIGBUS, &act, NULL);
+
+ /*
+ * addl %d0,#0 -- with immediate as destination is illegal.
+ * Buggy qemu interpreted the insn as 5 words: 2 for immediate source
+ * and another 2 for immediate destination. Provide all that padding
+ * so that abort gets called.
+ */
+ asm volatile(".word 0xd1bc,0,0,0,0");
+
+ abort();
+}
diff --git a/tests/tcg/m68k/Makefile.target b/tests/tcg/m68k/Makefile.target
index 1163c7ef03..d3b0bc48a3 100644
--- a/tests/tcg/m68k/Makefile.target
+++ b/tests/tcg/m68k/Makefile.target
@@ -4,6 +4,7 @@
#
VPATH += $(SRC_PATH)/tests/tcg/m68k
+TESTS += excp-address
TESTS += trap
# On m68k Linux supports 4k and 8k pages (but 8k is currently broken)
--
2.34.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] target/m68k: Reject immediate as destination in gen_ea_mode
2023-03-09 20:16 ` [PATCH v2 1/2] target/m68k: Reject immediate as destination in gen_ea_mode Richard Henderson
@ 2023-03-10 10:03 ` Laurent Vivier
2023-03-15 16:41 ` Laurent Vivier
1 sibling, 0 replies; 7+ messages in thread
From: Laurent Vivier @ 2023-03-10 10:03 UTC (permalink / raw)
To: Richard Henderson, qemu-devel
Le 09/03/2023 à 21:16, Richard Henderson a écrit :
> In theory this should never happen, as all such instructions
> are illegal. This is checked in e.g. gen_lea_mode and
> gen_ea_mode_fp but not here. In case something higher up
> isn't checking modes properly, return NULL_QREG. This will
> result in an illegal instruction exception being raised.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> target/m68k/translate.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/target/m68k/translate.c b/target/m68k/translate.c
> index 422f4652f1..e16c608ef8 100644
> --- a/target/m68k/translate.c
> +++ b/target/m68k/translate.c
> @@ -894,6 +894,10 @@ static TCGv gen_ea_mode(CPUM68KState *env, DisasContext *s, int mode, int reg0,
> case 3: /* pc index+displacement. */
> goto do_indirect;
> case 4: /* Immediate. */
> + /* Should never be used for an output or RMW input. */
> + if (what == EA_STORE || addrp) {
> + return NULL_QREG;
> + }
> /* Sign extend values for consistency. */
> switch (opsize) {
> case OS_BYTE:
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] target/m68k: Reject immediate as destination in gen_ea_mode
2023-03-09 20:16 ` [PATCH v2 1/2] target/m68k: Reject immediate as destination in gen_ea_mode Richard Henderson
2023-03-10 10:03 ` Laurent Vivier
@ 2023-03-15 16:41 ` Laurent Vivier
1 sibling, 0 replies; 7+ messages in thread
From: Laurent Vivier @ 2023-03-15 16:41 UTC (permalink / raw)
To: Richard Henderson, qemu-devel
Le 09/03/2023 à 21:16, Richard Henderson a écrit :
> In theory this should never happen, as all such instructions
> are illegal. This is checked in e.g. gen_lea_mode and
> gen_ea_mode_fp but not here. In case something higher up
> isn't checking modes properly, return NULL_QREG. This will
> result in an illegal instruction exception being raised.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> target/m68k/translate.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/target/m68k/translate.c b/target/m68k/translate.c
> index 422f4652f1..e16c608ef8 100644
> --- a/target/m68k/translate.c
> +++ b/target/m68k/translate.c
> @@ -894,6 +894,10 @@ static TCGv gen_ea_mode(CPUM68KState *env, DisasContext *s, int mode, int reg0,
> case 3: /* pc index+displacement. */
> goto do_indirect;
> case 4: /* Immediate. */
> + /* Should never be used for an output or RMW input. */
> + if (what == EA_STORE || addrp) {
> + return NULL_QREG;
> + }
> /* Sign extend values for consistency. */
> switch (opsize) {
> case OS_BYTE:
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] linux-user/m68k: Handle EXCP_ADDRESS in cpu_loop
2023-03-09 20:16 ` [PATCH v2 2/2] linux-user/m68k: Handle EXCP_ADDRESS in cpu_loop Richard Henderson
@ 2023-03-15 18:16 ` Laurent Vivier
2023-03-16 14:23 ` Richard Henderson
0 siblings, 1 reply; 7+ messages in thread
From: Laurent Vivier @ 2023-03-15 18:16 UTC (permalink / raw)
To: Richard Henderson, qemu-devel
Le 09/03/2023 à 21:16, Richard Henderson a écrit :
> This exception can be raised by illegal instructions.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> linux-user/m68k/cpu_loop.c | 5 ++++-
> tests/tcg/m68k/excp-address.c | 32 ++++++++++++++++++++++++++++++++
> tests/tcg/m68k/Makefile.target | 1 +
> 3 files changed, 37 insertions(+), 1 deletion(-)
> create mode 100644 tests/tcg/m68k/excp-address.c
>
> diff --git a/linux-user/m68k/cpu_loop.c b/linux-user/m68k/cpu_loop.c
> index caead1cb74..84b5d290c0 100644
> --- a/linux-user/m68k/cpu_loop.c
> +++ b/linux-user/m68k/cpu_loop.c
> @@ -35,7 +35,10 @@ void cpu_loop(CPUM68KState *env)
> cpu_exec_end(cs);
> process_queued_cpu_work(cs);
>
> - switch(trapnr) {
> + switch (trapnr) {
> + case EXCP_ADDRESS:
> + force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, env->pc);
> + break;
> case EXCP_ILLEGAL:
> case EXCP_LINEA:
> case EXCP_LINEF:
> diff --git a/tests/tcg/m68k/excp-address.c b/tests/tcg/m68k/excp-address.c
> new file mode 100644
> index 0000000000..1dbdddef58
> --- /dev/null
> +++ b/tests/tcg/m68k/excp-address.c
> @@ -0,0 +1,32 @@
> +/*
> + * Test m68k address exception
> + */
> +
> +#define _GNU_SOURCE 1
> +#include <signal.h>
> +#include <stdlib.h>
> +
> +static void sig_handler(int sig, siginfo_t *si, void *puc)
> +{
> + exit(0);
> +}
> +
> +int main(int argc, char **argv)
> +{
> + struct sigaction act = {
> + .sa_sigaction = sig_handler,
> + .sa_flags = SA_SIGINFO
> + };
> +
> + sigaction(SIGBUS, &act, NULL);
> +
> + /*
> + * addl %d0,#0 -- with immediate as destination is illegal.
> + * Buggy qemu interpreted the insn as 5 words: 2 for immediate source
> + * and another 2 for immediate destination. Provide all that padding
> + * so that abort gets called.
> + */
> + asm volatile(".word 0xd1bc,0,0,0,0");
> +
> + abort();
> +}
> diff --git a/tests/tcg/m68k/Makefile.target b/tests/tcg/m68k/Makefile.target
> index 1163c7ef03..d3b0bc48a3 100644
> --- a/tests/tcg/m68k/Makefile.target
> +++ b/tests/tcg/m68k/Makefile.target
> @@ -4,6 +4,7 @@
> #
>
> VPATH += $(SRC_PATH)/tests/tcg/m68k
> +TESTS += excp-address
> TESTS += trap
>
> # On m68k Linux supports 4k and 8k pages (but 8k is currently broken)
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
I've tested tests/tcg/m68k/excp-address.c on a real hardware (Q800), and the result differs from the
one from QEMU:
On Q800 (etch m68k, kernel 5.14.0):
$ ./excp-address
Illegal instruction
$ strace ./excp-address
...
rt_sigaction(SIGBUS, {0x80000478, [], SA_SIGINFO}, NULL, 8) = 0
--- SIGILL (Illegal instruction) @ 0 (0) ---
+++ killed by SIGILL +++
With QEMU, we have:
# QEMU_STRACE= ./excp-address
...
677354 rt_sigaction(SIGBUS,0x40800454,NULL) = 0
--- SIGBUS {si_signo=SIGBUS, si_code=1, si_addr=0x800004ce} ---
677354 exit_group(0)
Thanks,
Laurent
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] linux-user/m68k: Handle EXCP_ADDRESS in cpu_loop
2023-03-15 18:16 ` Laurent Vivier
@ 2023-03-16 14:23 ` Richard Henderson
0 siblings, 0 replies; 7+ messages in thread
From: Richard Henderson @ 2023-03-16 14:23 UTC (permalink / raw)
To: Laurent Vivier, qemu-devel
On 3/15/23 11:16, Laurent Vivier wrote:
> I've tested tests/tcg/m68k/excp-address.c on a real hardware (Q800), and the result
> differs from the one from QEMU:
>
> On Q800 (etch m68k, kernel 5.14.0):
>
> $ ./excp-address
> Illegal instruction
> $ strace ./excp-address
> ...
> rt_sigaction(SIGBUS, {0x80000478, [], SA_SIGINFO}, NULL, 8) = 0
> --- SIGILL (Illegal instruction) @ 0 (0) ---
> +++ killed by SIGILL +++
Ok, that suggests that we need to do something different in the translator in patch 1.
I'll give it some thought.
r~
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2023-03-16 14:24 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2023-03-09 20:16 [PATCH v2 0/2] target/m68k: Reject immediate as destination Richard Henderson
2023-03-09 20:16 ` [PATCH v2 1/2] target/m68k: Reject immediate as destination in gen_ea_mode Richard Henderson
2023-03-10 10:03 ` Laurent Vivier
2023-03-15 16:41 ` Laurent Vivier
2023-03-09 20:16 ` [PATCH v2 2/2] linux-user/m68k: Handle EXCP_ADDRESS in cpu_loop Richard Henderson
2023-03-15 18:16 ` Laurent Vivier
2023-03-16 14:23 ` Richard Henderson
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