2022-07-14 06:31:00

by Qi Hu

Subject: [PATCH] LoongArch: Fix missing fcsr in ptrace's fpr_set

In file ptrace.c, function fpr_set does not copy fcsr data from ubuf
to kbuf. That's the reason why fcsr cannot be modified by ptrace.

This patch fixs this problem and allows users using ptrace to modify
the fcsr.

Signed-off-by: Qi Hu <[email protected]>
Signed-off-by: Xu Li <[email protected]>
---
arch/loongarch/kernel/ptrace.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
index e6ab87948e1d..dc2b82ea894c 100644
--- a/arch/loongarch/kernel/ptrace.c
+++ b/arch/loongarch/kernel/ptrace.c
@@ -193,7 +193,7 @@ static int fpr_set(struct task_struct *target,
const void *kbuf, const void __user *ubuf)
{
const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
- const int fcc_end = fcc_start + sizeof(u64);
+ const int fcsr_start = fcc_start + sizeof(u64);
int err;

BUG_ON(count % sizeof(elf_fpreg_t));
@@ -209,10 +209,12 @@ static int fpr_set(struct task_struct *target,
if (err)
return err;

- if (count > 0)
- err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
- &target->thread.fpu.fcc,
- fcc_start, fcc_end);
+ err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.fpu.fcc, fcc_start,
+ fcc_start + sizeof(u64));
+ err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.fpu.fcsr, fcsr_start,
+ fcsr_start + sizeof(u32));

return err;
}
--
2.37.0

2022-07-14 07:08:23

by Conor Dooley

Subject: Re: [PATCH] LoongArch: Fix missing fcsr in ptrace's fpr_set

On 14/07/2022 07:25, Qi Hu wrote:
> In file ptrace.c, function fpr_set does not copy fcsr data from ubuf
> to kbuf. That's the reason why fcsr cannot be modified by ptrace.
>
> This patch fixs this problem and allows users using ptrace to modify
> the fcsr.
>
> Signed-off-by: Qi Hu <[email protected]>
> Signed-off-by: Xu Li <[email protected]>

Hey Qi Hu,

Why does this have Xu Li's SoB if they're neither the author nor listed
as a Co-developed-by:?

As submitter, your SoB should be last anyway.
Thanks,
Conor.

> ---
> arch/loongarch/kernel/ptrace.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
> index e6ab87948e1d..dc2b82ea894c 100644
> --- a/arch/loongarch/kernel/ptrace.c
> +++ b/arch/loongarch/kernel/ptrace.c
> @@ -193,7 +193,7 @@ static int fpr_set(struct task_struct *target,
> const void *kbuf, const void __user *ubuf)
> {
> const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
> - const int fcc_end = fcc_start + sizeof(u64);
> + const int fcsr_start = fcc_start + sizeof(u64);
> int err;
>
> BUG_ON(count % sizeof(elf_fpreg_t));
> @@ -209,10 +209,12 @@ static int fpr_set(struct task_struct *target,
> if (err)
> return err;
>
> - if (count > 0)
> - err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> - &target->thread.fpu.fcc,
> - fcc_start, fcc_end);
> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> + &target->thread.fpu.fcc, fcc_start,
> + fcc_start + sizeof(u64));
> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> + &target->thread.fpu.fcsr, fcsr_start,
> + fcsr_start + sizeof(u32));
>
> return err;
> }

2022-07-14 07:40:58

by Qi Hu

Subject: Re: [PATCH] LoongArch: Fix missing fcsr in ptrace's fpr_set

On 2022/7/14 14:51, [email protected] wrote:
> On 14/07/2022 07:25, Qi Hu wrote:
>> In file ptrace.c, function fpr_set does not copy fcsr data from ubuf
>> to kbuf. That's the reason why fcsr cannot be modified by ptrace.
>>
>> This patch fixs this problem and allows users using ptrace to modify
>> the fcsr.
>>
>> Signed-off-by: Qi Hu <[email protected]>
>> Signed-off-by: Xu Li <[email protected]>
> Hey Qi Hu,
>
> Why does this have Xu Li's SoB if they're neither the author nor listed
> as a Co-developed-by:?
>
> As submitter, your SoB should be last anyway.
> Thanks,
> Conor.
>
Ops. I realize using SoB here is incorrect. I will change it into
Co-developed-by.

Thanks.

Qi.

>> ---
>> arch/loongarch/kernel/ptrace.c | 12 +++++++-----
>> 1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
>> index e6ab87948e1d..dc2b82ea894c 100644
>> --- a/arch/loongarch/kernel/ptrace.c
>> +++ b/arch/loongarch/kernel/ptrace.c
>> @@ -193,7 +193,7 @@ static int fpr_set(struct task_struct *target,
>> const void *kbuf, const void __user *ubuf)
>> {
>> const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
>> - const int fcc_end = fcc_start + sizeof(u64);
>> + const int fcsr_start = fcc_start + sizeof(u64);
>> int err;
>>
>> BUG_ON(count % sizeof(elf_fpreg_t));
>> @@ -209,10 +209,12 @@ static int fpr_set(struct task_struct *target,
>> if (err)
>> return err;
>>
>> - if (count > 0)
>> - err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> - &target->thread.fpu.fcc,
>> - fcc_start, fcc_end);
>> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> + &target->thread.fpu.fcc, fcc_start,
>> + fcc_start + sizeof(u64));
>> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> + &target->thread.fpu.fcsr, fcsr_start,
>> + fcsr_start + sizeof(u32));
>>
>> return err;
>> }

2022-07-14 13:49:50

by Huacai Chen

Subject: Re: [PATCH] LoongArch: Fix missing fcsr in ptrace's fpr_set

Hi,

On Thu, Jul 14, 2022 at 2:26 PM Qi Hu <[email protected]> wrote:
>
> In file ptrace.c, function fpr_set does not copy fcsr data from ubuf
> to kbuf. That's the reason why fcsr cannot be modified by ptrace.
>
> This patch fixs this problem and allows users using ptrace to modify
> the fcsr.
>
> Signed-off-by: Qi Hu <[email protected]>
> Signed-off-by: Xu Li <[email protected]>
> ---
> arch/loongarch/kernel/ptrace.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
> index e6ab87948e1d..dc2b82ea894c 100644
> --- a/arch/loongarch/kernel/ptrace.c
> +++ b/arch/loongarch/kernel/ptrace.c
> @@ -193,7 +193,7 @@ static int fpr_set(struct task_struct *target,
> const void *kbuf, const void __user *ubuf)
> {
> const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
> - const int fcc_end = fcc_start + sizeof(u64);
> + const int fcsr_start = fcc_start + sizeof(u64);
> int err;
>
> BUG_ON(count % sizeof(elf_fpreg_t));
> @@ -209,10 +209,12 @@ static int fpr_set(struct task_struct *target,
> if (err)
> return err;
>
> - if (count > 0)
> - err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> - &target->thread.fpu.fcc,
> - fcc_start, fcc_end);
> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> + &target->thread.fpu.fcc, fcc_start,
> + fcc_start + sizeof(u64));
> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> + &target->thread.fpu.fcsr, fcsr_start,
> + fcsr_start + sizeof(u32));
You shouldn't remove (count > 0) here, because the above
user_regset_copyin() will modify count inside, and so "count == 0" is
possible.

Huacai
>
> return err;
> }
> --
> 2.37.0
>

2022-07-14 14:17:07

by Qi Hu

Subject: Re: [PATCH] LoongArch: Fix missing fcsr in ptrace's fpr_set

On 2022/7/14 21:12, Huacai Chen wrote:
> Hi,
>
> On Thu, Jul 14, 2022 at 2:26 PM Qi Hu <[email protected]> wrote:
>> In file ptrace.c, function fpr_set does not copy fcsr data from ubuf
>> to kbuf. That's the reason why fcsr cannot be modified by ptrace.
>>
>> This patch fixs this problem and allows users using ptrace to modify
>> the fcsr.
>>
>> Signed-off-by: Qi Hu <[email protected]>
>> Signed-off-by: Xu Li <[email protected]>
>> ---
>> arch/loongarch/kernel/ptrace.c | 12 +++++++-----
>> 1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
>> index e6ab87948e1d..dc2b82ea894c 100644
>> --- a/arch/loongarch/kernel/ptrace.c
>> +++ b/arch/loongarch/kernel/ptrace.c
>> @@ -193,7 +193,7 @@ static int fpr_set(struct task_struct *target,
>> const void *kbuf, const void __user *ubuf)
>> {
>> const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
>> - const int fcc_end = fcc_start + sizeof(u64);
>> + const int fcsr_start = fcc_start + sizeof(u64);
>> int err;
>>
>> BUG_ON(count % sizeof(elf_fpreg_t));
>> @@ -209,10 +209,12 @@ static int fpr_set(struct task_struct *target,
>> if (err)
>> return err;
>>
>> - if (count > 0)
>> - err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> - &target->thread.fpu.fcc,
>> - fcc_start, fcc_end);
>> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> + &target->thread.fpu.fcc, fcc_start,
>> + fcc_start + sizeof(u64));
>> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> + &target->thread.fpu.fcsr, fcsr_start,
>> + fcsr_start + sizeof(u32));
> You shouldn't remove (count > 0) here, because the above
> user_regset_copyin() will modify count inside, and so "count == 0" is
> possible.
>
> Huacai

Yes, the "count" should be considered. But the "count" is checked at the
beginning of the "user_regset_copyin()".

So "count > 0" is useless, i think.

Also like riscv, "count" is not checked in "riscv_fpr_set()".

>> return err;
>> }
>> --
>> 2.37.0
>>

2022-07-15 03:26:06

by Huacai Chen

Subject: Re: [PATCH] LoongArch: Fix missing fcsr in ptrace's fpr_set

On Thu, Jul 14, 2022 at 10:07 PM Qi Hu <[email protected]> wrote:
>
>
> On 2022/7/14 21:12, Huacai Chen wrote:
> > Hi,
> >
> > On Thu, Jul 14, 2022 at 2:26 PM Qi Hu <[email protected]> wrote:
> >> In file ptrace.c, function fpr_set does not copy fcsr data from ubuf
> >> to kbuf. That's the reason why fcsr cannot be modified by ptrace.
> >>
> >> This patch fixs this problem and allows users using ptrace to modify
> >> the fcsr.
> >>
> >> Signed-off-by: Qi Hu <[email protected]>
> >> Signed-off-by: Xu Li <[email protected]>
> >> ---
> >> arch/loongarch/kernel/ptrace.c | 12 +++++++-----
> >> 1 file changed, 7 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
> >> index e6ab87948e1d..dc2b82ea894c 100644
> >> --- a/arch/loongarch/kernel/ptrace.c
> >> +++ b/arch/loongarch/kernel/ptrace.c
> >> @@ -193,7 +193,7 @@ static int fpr_set(struct task_struct *target,
> >> const void *kbuf, const void __user *ubuf)
> >> {
> >> const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
> >> - const int fcc_end = fcc_start + sizeof(u64);
> >> + const int fcsr_start = fcc_start + sizeof(u64);
> >> int err;
> >>
> >> BUG_ON(count % sizeof(elf_fpreg_t));
> >> @@ -209,10 +209,12 @@ static int fpr_set(struct task_struct *target,
> >> if (err)
> >> return err;
> >>
> >> - if (count > 0)
> >> - err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> >> - &target->thread.fpu.fcc,
> >> - fcc_start, fcc_end);
> >> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> >> + &target->thread.fpu.fcc, fcc_start,
> >> + fcc_start + sizeof(u64));
> >> + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> >> + &target->thread.fpu.fcsr, fcsr_start,
> >> + fcsr_start + sizeof(u32));
> > You shouldn't remove (count > 0) here, because the above
> > user_regset_copyin() will modify count inside, and so "count == 0" is
> > possible.
> >
> > Huacai
>
> Yes, the "count" should be considered. But the "count" is checked at the
> beginning of the "user_regset_copyin()".
>
> So "count > 0" is useless, i think.
Yes, you are right, thanks.

Huacai
>
> Also like riscv, "count" is not checked in "riscv_fpr_set()".
>
> >> return err;
> >> }
> >> --
> >> 2.37.0
> >>
>