I don't have a ppc machine, this patch wasn't even compile tested,
could you please review?
The commit a8a4b03ab95f ("powerpc: Hard wire PT_SOFTE value to 1 in
ptrace & signals") changed ptrace_get_reg(PT_SOFTE) to report 0x1,
but PTRACE_GETREGS still copies pt_regs->softe as is.
This is not consistent and this breaks
http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
Reported-by: Jan Kratochvil <[email protected]>
Signed-off-by: Oleg Nesterov <[email protected]>
---
arch/powerpc/kernel/ptrace.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8c92feb..9e9342c 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -363,11 +363,36 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset,
BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
offsetof(struct pt_regs, msr) + sizeof(long));
+#ifdef CONFIG_PPC64
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.regs->orig_gpr3,
+ offsetof(struct pt_regs, orig_gpr3),
+ offsetof(struct pt_regs, softe));
+
+ if (!ret) {
+ unsigned long softe = 0x1;
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
+ offsetof(struct pt_regs, softe),
+ offsetof(struct pt_regs, softe) +
+ sizeof(softe));
+ }
+
+ BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
+ offsetof(struct pt_regs, softe) + sizeof(long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.regs->trap,
+ offsetof(struct pt_regs, trap),
+ sizeof(struct user_pt_regs));
+#else
if (!ret)
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.regs->orig_gpr3,
offsetof(struct pt_regs, orig_gpr3),
sizeof(struct user_pt_regs));
+#endif
if (!ret)
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
sizeof(struct user_pt_regs), -1);
--
2.5.0
I don't have a ppc machine, this patch wasn't even compile tested,
could you please review?
The commit a8a4b03ab95f ("powerpc: Hard wire PT_SOFTE value to 1 in
ptrace & signals") changed ptrace_get_reg(PT_SOFTE) to report 0x1,
but PTRACE_GETREGS still copies pt_regs->softe as is.
This is not consistent and this breaks
http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
Reported-by: Jan Kratochvil <[email protected]>
Signed-off-by: Oleg Nesterov <[email protected]>
---
arch/powerpc/kernel/ptrace.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8c92feb..291acfb 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -363,11 +363,36 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset,
BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
offsetof(struct pt_regs, msr) + sizeof(long));
+#ifdef CONFIG_PPC64
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.regs->orig_gpr3,
+ offsetof(struct pt_regs, orig_gpr3),
+ offsetof(struct pt_regs, softe));
+
+ if (!ret) {
+ unsigned long softe = 0x1;
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &softe,
+ offsetof(struct pt_regs, softe),
+ offsetof(struct pt_regs, softe) +
+ sizeof(softe));
+ }
+
+ BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
+ offsetof(struct pt_regs, softe) + sizeof(long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.regs->trap,
+ offsetof(struct pt_regs, trap),
+ sizeof(struct user_pt_regs));
+#else
if (!ret)
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.regs->orig_gpr3,
offsetof(struct pt_regs, orig_gpr3),
sizeof(struct user_pt_regs));
+#endif
if (!ret)
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
sizeof(struct user_pt_regs), -1);
--
2.5.0
Hi Oleg,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[cannot apply to v5.3 next-20190916]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Oleg-Nesterov/powerpc-Hard-wire-PT_SOFTE-value-to-1-in-gpr_get-too/20190917-201613
config: powerpc-allmodconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 7.4.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
GCC_VERSION=7.4.0 make.cross ARCH=powerpc
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <[email protected]>
All errors (new ones prefixed by >>):
arch/powerpc/kernel/ptrace.c: In function 'gpr_get':
>> arch/powerpc/kernel/ptrace.c:375:58: error: 'msr' undeclared (first use in this function)
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
^~~
arch/powerpc/kernel/ptrace.c:375:58: note: each undeclared identifier is reported only once for each function it appears in
vim +/msr +375 arch/powerpc/kernel/ptrace.c
336
337 static int gpr_get(struct task_struct *target, const struct user_regset *regset,
338 unsigned int pos, unsigned int count,
339 void *kbuf, void __user *ubuf)
340 {
341 int i, ret;
342
343 if (target->thread.regs == NULL)
344 return -EIO;
345
346 if (!FULL_REGS(target->thread.regs)) {
347 /* We have a partial register set. Fill 14-31 with bogus values */
348 for (i = 14; i < 32; i++)
349 target->thread.regs->gpr[i] = NV_REG_POISON;
350 }
351
352 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
353 target->thread.regs,
354 0, offsetof(struct pt_regs, msr));
355 if (!ret) {
356 unsigned long msr = get_user_msr(target);
357 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
358 offsetof(struct pt_regs, msr),
359 offsetof(struct pt_regs, msr) +
360 sizeof(msr));
361 }
362
363 BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
364 offsetof(struct pt_regs, msr) + sizeof(long));
365
366 #ifdef CONFIG_PPC64
367 if (!ret)
368 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
369 &target->thread.regs->orig_gpr3,
370 offsetof(struct pt_regs, orig_gpr3),
371 offsetof(struct pt_regs, softe));
372
373 if (!ret) {
374 unsigned long softe = 0x1;
> 375 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
376 offsetof(struct pt_regs, softe),
377 offsetof(struct pt_regs, softe) +
378 sizeof(softe));
379 }
380
381 BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
382 offsetof(struct pt_regs, softe) + sizeof(long));
383
384 if (!ret)
385 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
386 &target->thread.regs->trap,
387 offsetof(struct pt_regs, trap),
388 sizeof(struct user_pt_regs));
389 #else
390 if (!ret)
391 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
392 &target->thread.regs->orig_gpr3,
393 offsetof(struct pt_regs, orig_gpr3),
394 sizeof(struct user_pt_regs));
395 #endif
396 if (!ret)
397 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
398 sizeof(struct user_pt_regs), -1);
399
400 return ret;
401 }
402
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi Oleg,
Thanks for the patch.
Oleg Nesterov <[email protected]> writes:
> I don't have a ppc machine, this patch wasn't even compile tested,
> could you please review?
>
> The commit a8a4b03ab95f ("powerpc: Hard wire PT_SOFTE value to 1 in
> ptrace & signals") changed ptrace_get_reg(PT_SOFTE) to report 0x1,
> but PTRACE_GETREGS still copies pt_regs->softe as is.
Ugh, that certainly seems broken. I guess we forgot/didn't-know that
there were two paths through ptrace to get the one register.
> This is not consistent and this breaks
> http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
That's a 404 for me?
Is it this: https://sourceware.org/systemtap/wiki/utrace/tests/
That seems to point me to a CVS repo? Which then didn't build. But now I
have that one test built, and you're right it fails with:
$ ./user-regs-peekpoke
mismatch at offset 0x138: poked 0 but peeked 1
> Reported-by: Jan Kratochvil <[email protected]>
> Signed-off-by: Oleg Nesterov <[email protected]>
> ---
> arch/powerpc/kernel/ptrace.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
> index 8c92feb..9e9342c 100644
> --- a/arch/powerpc/kernel/ptrace.c
> +++ b/arch/powerpc/kernel/ptrace.c
> @@ -363,11 +363,36 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset,
> BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
> offsetof(struct pt_regs, msr) + sizeof(long));
>
> +#ifdef CONFIG_PPC64
> + if (!ret)
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> + &target->thread.regs->orig_gpr3,
> + offsetof(struct pt_regs, orig_gpr3),
> + offsetof(struct pt_regs, softe));
> +
> + if (!ret) {
> + unsigned long softe = 0x1;
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
> + offsetof(struct pt_regs, softe),
> + offsetof(struct pt_regs, softe) +
> + sizeof(softe));
> + }
> +
> + BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
> + offsetof(struct pt_regs, softe) + sizeof(long));
> +
> + if (!ret)
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> + &target->thread.regs->trap,
> + offsetof(struct pt_regs, trap),
> + sizeof(struct user_pt_regs));
> +#else
> if (!ret)
> ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> &target->thread.regs->orig_gpr3,
> offsetof(struct pt_regs, orig_gpr3),
> sizeof(struct user_pt_regs));
> +#endif
> if (!ret)
> ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
> sizeof(struct user_pt_regs), -1);
It would be nice if we could isolate the special logic in once place,
ie. ptrace_get_reg().
We could do it like below. I'm 50/50 though on whether it's worth it, or
if we should just go with the big ifdef like in your patch.
cheers
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8c92febf5f44..55510f1a7ec1 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -334,6 +334,11 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
return -EIO;
}
+#ifndef __powerpc64__
+/* Needed on 32-bit to make the SOFTE logic below work without ifdefs */
+#define PT_SOFTE PT_MQ
+#endif
+
static int gpr_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
@@ -367,6 +372,24 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset,
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.regs->orig_gpr3,
offsetof(struct pt_regs, orig_gpr3),
+ PT_SOFTE * sizeof(long));
+
+ /* SOFTE is special on 64-bit, the logic is in ptrace_get_reg() */
+ if (!ret) {
+ unsigned long val = 0;
+ ptrace_get_reg(target, PT_SOFTE, &val);
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &val,
+ PT_SOFTE * sizeof(long),
+ offsetof(struct pt_regs, trap));
+ }
+
+ BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
+ (PT_SOFTE * sizeof(long)) + sizeof(long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.regs->trap,
+ offsetof(struct pt_regs, trap),
sizeof(struct user_pt_regs));
if (!ret)
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
@@ -3384,9 +3407,13 @@ void __init pt_regs_check(void)
#ifdef __powerpc64__
BUILD_BUG_ON(offsetof(struct pt_regs, softe) !=
offsetof(struct user_pt_regs, softe));
+ BUILD_BUG_ON(offsetof(struct pt_regs, softe) !=
+ PT_SOFTE * sizeof(long));
#else
BUILD_BUG_ON(offsetof(struct pt_regs, mq) !=
offsetof(struct user_pt_regs, mq));
+ BUILD_BUG_ON(offsetof(struct pt_regs, mq) !=
+ PT_MQ * sizeof(long));
#endif
BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
offsetof(struct user_pt_regs, trap));
Hi,
looks like this patch was forgotten.
Do you think this should be fixed or should we document that
PTRACE_GETREGS is not consistent with PTRACE_PEEKUSER on ppc64?
On 09/17, Oleg Nesterov wrote:
>
> I don't have a ppc machine, this patch wasn't even compile tested,
> could you please review?
>
> The commit a8a4b03ab95f ("powerpc: Hard wire PT_SOFTE value to 1 in
> ptrace & signals") changed ptrace_get_reg(PT_SOFTE) to report 0x1,
> but PTRACE_GETREGS still copies pt_regs->softe as is.
>
> This is not consistent and this breaks
> http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
>
> Reported-by: Jan Kratochvil <[email protected]>
> Signed-off-by: Oleg Nesterov <[email protected]>
> ---
> arch/powerpc/kernel/ptrace.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
> index 8c92feb..291acfb 100644
> --- a/arch/powerpc/kernel/ptrace.c
> +++ b/arch/powerpc/kernel/ptrace.c
> @@ -363,11 +363,36 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset,
> BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
> offsetof(struct pt_regs, msr) + sizeof(long));
>
> +#ifdef CONFIG_PPC64
> + if (!ret)
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> + &target->thread.regs->orig_gpr3,
> + offsetof(struct pt_regs, orig_gpr3),
> + offsetof(struct pt_regs, softe));
> +
> + if (!ret) {
> + unsigned long softe = 0x1;
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &softe,
> + offsetof(struct pt_regs, softe),
> + offsetof(struct pt_regs, softe) +
> + sizeof(softe));
> + }
> +
> + BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
> + offsetof(struct pt_regs, softe) + sizeof(long));
> +
> + if (!ret)
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> + &target->thread.regs->trap,
> + offsetof(struct pt_regs, trap),
> + sizeof(struct user_pt_regs));
> +#else
> if (!ret)
> ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> &target->thread.regs->orig_gpr3,
> offsetof(struct pt_regs, orig_gpr3),
> sizeof(struct user_pt_regs));
> +#endif
> if (!ret)
> ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
> sizeof(struct user_pt_regs), -1);
> --
> 2.5.0
>
On 6/10/20 8:37 PM, Oleg Nesterov wrote:
> Hi,
>
> looks like this patch was forgotten.
yep, I missed this. But mpe did have comments for the patch.
https://lkml.org/lkml/2019/9/19/107
Maddy
>
> Do you think this should be fixed or should we document that
> PTRACE_GETREGS is not consistent with PTRACE_PEEKUSER on ppc64?
>
>
> On 09/17, Oleg Nesterov wrote:
>> I don't have a ppc machine, this patch wasn't even compile tested,
>> could you please review?
>>
>> The commit a8a4b03ab95f ("powerpc: Hard wire PT_SOFTE value to 1 in
>> ptrace & signals") changed ptrace_get_reg(PT_SOFTE) to report 0x1,
>> but PTRACE_GETREGS still copies pt_regs->softe as is.
>>
>> This is not consistent and this breaks
>> http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
>>
>> Reported-by: Jan Kratochvil <[email protected]>
>> Signed-off-by: Oleg Nesterov <[email protected]>
>> ---
>> arch/powerpc/kernel/ptrace.c | 25 +++++++++++++++++++++++++
>> 1 file changed, 25 insertions(+)
>>
>> diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
>> index 8c92feb..291acfb 100644
>> --- a/arch/powerpc/kernel/ptrace.c
>> +++ b/arch/powerpc/kernel/ptrace.c
>> @@ -363,11 +363,36 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset,
>> BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
>> offsetof(struct pt_regs, msr) + sizeof(long));
>>
>> +#ifdef CONFIG_PPC64
>> + if (!ret)
>> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
>> + &target->thread.regs->orig_gpr3,
>> + offsetof(struct pt_regs, orig_gpr3),
>> + offsetof(struct pt_regs, softe));
>> +
>> + if (!ret) {
>> + unsigned long softe = 0x1;
>> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &softe,
>> + offsetof(struct pt_regs, softe),
>> + offsetof(struct pt_regs, softe) +
>> + sizeof(softe));
>> + }
>> +
>> + BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
>> + offsetof(struct pt_regs, softe) + sizeof(long));
>> +
>> + if (!ret)
>> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
>> + &target->thread.regs->trap,
>> + offsetof(struct pt_regs, trap),
>> + sizeof(struct user_pt_regs));
>> +#else
>> if (!ret)
>> ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
>> &target->thread.regs->orig_gpr3,
>> offsetof(struct pt_regs, orig_gpr3),
>> sizeof(struct user_pt_regs));
>> +#endif
>> if (!ret)
>> ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
>> sizeof(struct user_pt_regs), -1);
>> --
>> 2.5.0
>>
On Thu, 11 Jun 2020 12:58:31 +0200, Oleg Nesterov wrote:
> On 06/11, Madhavan Srinivasan wrote:
> > On 6/10/20 8:37 PM, Oleg Nesterov wrote:
> > > > This is not consistent and this breaks
> > > > http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
>
> this is 404.
Attaching the testcase, the CVS web interface no longer works on
sourceware.org.
Jan
On 06/11, Madhavan Srinivasan wrote:
>
>
> On 6/10/20 8:37 PM, Oleg Nesterov wrote:
> >Hi,
> >
> >looks like this patch was forgotten.
>
> yep, I missed this. But mpe did have comments for the patch.
>
> https://lkml.org/lkml/2019/9/19/107
Yes, and I thought that I have replied... apparently not, sorry!
So let me repeat, I am fine either way, I do not understand this
ppc-specific code and I can't really test this change.
Let me quote that email from Michael:
> We could do it like below. I'm 50/50 though on whether it's worth it, or
> if we should just go with the big ifdef like in your patch.
up to you ;)
Hmm. And yes,
> >>This is not consistent and this breaks
> >>http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
this is 404.
Jan, could correct the link above?
Oleg.