diff mbox series

[v6,2/5] linux: Use long time_t __getitimer/__setitimer

Message ID 20200328152249.972428-3-alistair.francis@wdc.com
State New, archived
Headers
Series Always use 32-bit time_t for certain syscalls |

Commit Message

Alistair Francis March 28, 2020, 3:22 p.m. UTC 
  The Linux kernel expects itimerval to use a 32-bit time_t, even on archs
with a 64-bit time_t (like RV32). To address this let's convert
itimerval to/from 32-bit and 64-bit to ensure the kernel always gets
a 32-bit time_t.

While we are converting these functions let's also convert them to be
the y2038 safe versions. This means there is a *64 function that is
called by a backwards compatible wrapper.

Tested-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
---
 include/time.h                        | 15 +++++
 sysdeps/unix/syscalls.list            |  2 -
 sysdeps/unix/sysv/linux/getitimer.c   | 59 +++++++++++++++++
 sysdeps/unix/sysv/linux/setitimer.c   | 94 +++++++++++++++++++++++++++
 sysdeps/unix/sysv/linux/tv32-compat.h | 31 +++++++++
 5 files changed, 199 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/getitimer.c
 create mode 100644 sysdeps/unix/sysv/linux/setitimer.c
 create mode 100644 sysdeps/unix/sysv/linux/tv32-compat.h

Comments

Stepan Golosunov March 29, 2020, 9:59 a.m. UTC | #1 
28.03.2020 в 08:22:46 -0700 Alistair Francis написал:
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/getitimer.c

> +int
> +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
> +{
> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
> +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
> +#else
> +  struct __itimerval32 curr_value_32;
> +
> +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
> +    return -1;
> +
> +  curr_value->it_interval
> +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
> +  curr_value->it_value
> +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
> +  return 0;
> +#endif
> +}
> +
> +#if __TIMESIZE != 64
> +libc_hidden_def (__getitimer64)
> +int
> +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
> +{
> +  struct __itimerval64 val64;
> +
> +  val64.it_interval
> +    = valid_timeval_to_timeval64 (curr_value->it_interval);
> +  val64.it_value
> +    = valid_timeval_to_timeval64 (curr_value->it_value);
> +
> +  return __getitimer64 (which, &val64);
> +}
> +#endif
> +weak_alias (__getitimer, getitimer)

__getitimer treats curr_value as input-only variable, while it's an
output-only one in __getitimer64.  This won't work.
Alistair Francis March 29, 2020, 6:17 p.m. UTC | #2 
On Sun, Mar 29, 2020 at 2:59 AM Stepan Golosunov <stepan@golosunov.pp.ru> wrote:
>
> 28.03.2020 в 08:22:46 -0700 Alistair Francis написал:
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/getitimer.c
>
> > +int
> > +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
> > +{
> > +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
> > +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
> > +#else
> > +  struct __itimerval32 curr_value_32;
> > +
> > +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
> > +    return -1;
> > +
> > +  curr_value->it_interval
> > +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
> > +  curr_value->it_value
> > +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
> > +  return 0;
> > +#endif
> > +}
> > +
> > +#if __TIMESIZE != 64
> > +libc_hidden_def (__getitimer64)
> > +int
> > +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
> > +{
> > +  struct __itimerval64 val64;
> > +
> > +  val64.it_interval
> > +    = valid_timeval_to_timeval64 (curr_value->it_interval);
> > +  val64.it_value
> > +    = valid_timeval_to_timeval64 (curr_value->it_value);
> > +
> > +  return __getitimer64 (which, &val64);
> > +}
> > +#endif
> > +weak_alias (__getitimer, getitimer)
>
> __getitimer treats curr_value as input-only variable, while it's an
> output-only one in __getitimer64.  This won't work.

I'm not sure what you mean here, can you please elaborate?

Alistair
Stepan Golosunov March 29, 2020, 10:19 p.m. UTC | #3 
29.03.2020 в 11:17:17 -0700 Alistair Francis написал:
> On Sun, Mar 29, 2020 at 2:59 AM Stepan Golosunov <stepan@golosunov.pp.ru> wrote:
> >
> > 28.03.2020 в 08:22:46 -0700 Alistair Francis написал:
> > > --- /dev/null
> > > +++ b/sysdeps/unix/sysv/linux/getitimer.c
> >
> > > +int
> > > +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
> > > +{
> > > +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
> > > +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
> > > +#else
> > > +  struct __itimerval32 curr_value_32;
> > > +
> > > +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
> > > +    return -1;
> > > +
> > > +  curr_value->it_interval
> > > +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
> > > +  curr_value->it_value
> > > +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
> > > +  return 0;
> > > +#endif
> > > +}
> > > +
> > > +#if __TIMESIZE != 64
> > > +libc_hidden_def (__getitimer64)
> > > +int
> > > +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
> > > +{
> > > +  struct __itimerval64 val64;
> > > +
> > > +  val64.it_interval
> > > +    = valid_timeval_to_timeval64 (curr_value->it_interval);
> > > +  val64.it_value
> > > +    = valid_timeval_to_timeval64 (curr_value->it_value);
> > > +
> > > +  return __getitimer64 (which, &val64);
> > > +}
> > > +#endif
> > > +weak_alias (__getitimer, getitimer)
> >
> > __getitimer treats curr_value as input-only variable, while it's an
> > output-only one in __getitimer64.  This won't work.
> 
> I'm not sure what you mean here, can you please elaborate?

__getitimer (…, &curr_value) will never write to curr_value (or do
anything useful with it at all); while 
__getitimer64 (…, &curr_value) will write to curr_value as expected.

Conversion in __getitimer shold be in opposite direction and after
__getitimer64 call.
Adhemerval Zanella March 30, 2020, 2:48 p.m. UTC | #4 
On 29/03/2020 19:19, Stepan Golosunov wrote:
> 29.03.2020 в 11:17:17 -0700 Alistair Francis написал:
>> On Sun, Mar 29, 2020 at 2:59 AM Stepan Golosunov <stepan@golosunov.pp.ru> wrote:
>>>
>>> 28.03.2020 в 08:22:46 -0700 Alistair Francis написал:
>>>> --- /dev/null
>>>> +++ b/sysdeps/unix/sysv/linux/getitimer.c
>>>
>>>> +int
>>>> +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
>>>> +{
>>>> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
>>>> +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
>>>> +#else
>>>> +  struct __itimerval32 curr_value_32;
>>>> +
>>>> +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
>>>> +    return -1;
>>>> +
>>>> +  curr_value->it_interval
>>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
>>>> +  curr_value->it_value
>>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
>>>> +  return 0;
>>>> +#endif
>>>> +}
>>>> +
>>>> +#if __TIMESIZE != 64
>>>> +libc_hidden_def (__getitimer64)
>>>> +int
>>>> +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
>>>> +{
>>>> +  struct __itimerval64 val64;
>>>> +
>>>> +  val64.it_interval
>>>> +    = valid_timeval_to_timeval64 (curr_value->it_interval);
>>>> +  val64.it_value
>>>> +    = valid_timeval_to_timeval64 (curr_value->it_value);
>>>> +
>>>> +  return __getitimer64 (which, &val64);
>>>> +}
>>>> +#endif
>>>> +weak_alias (__getitimer, getitimer)
>>>
>>> __getitimer treats curr_value as input-only variable, while it's an
>>> output-only one in __getitimer64.  This won't work.
>>
>> I'm not sure what you mean here, can you please elaborate?
> 
> __getitimer (…, &curr_value) will never write to curr_value (or do
> anything useful with it at all); while 
> __getitimer64 (…, &curr_value) will write to curr_value as expected.
> 
> Conversion in __getitimer shold be in opposite direction and after
> __getitimer64 call.
> 

Indeed, it should be:

  int
  __getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
  {
    [...]
  }

  #if __TIMESIZE != 64
  libc_hidden_def (__getitimer64)
  
  int
  __getitimer (__itimer_which_t which, struct itimerval *curr_value)
  {
    struct __itimerval64 val64;
    if (__getitimer64 (which, &val64) != 0)
      return -1;

    curr_value->it_interval
      = valid_timeval64_to_timeval (val64->it_interval);
    curr_value->it_value
      = valid_timeval64_to_timeval (val64->it_value);
 
    return 0;
  }
  #endif
Alistair Francis March 30, 2020, 4:17 p.m. UTC | #5 
On Mon, Mar 30, 2020 at 7:49 AM Adhemerval Zanella via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
>
>
> On 29/03/2020 19:19, Stepan Golosunov wrote:
> > 29.03.2020 в 11:17:17 -0700 Alistair Francis написал:
> >> On Sun, Mar 29, 2020 at 2:59 AM Stepan Golosunov <stepan@golosunov.pp.ru> wrote:
> >>>
> >>> 28.03.2020 в 08:22:46 -0700 Alistair Francis написал:
> >>>> --- /dev/null
> >>>> +++ b/sysdeps/unix/sysv/linux/getitimer.c
> >>>
> >>>> +int
> >>>> +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
> >>>> +{
> >>>> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
> >>>> +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
> >>>> +#else
> >>>> +  struct __itimerval32 curr_value_32;
> >>>> +
> >>>> +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
> >>>> +    return -1;
> >>>> +
> >>>> +  curr_value->it_interval
> >>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
> >>>> +  curr_value->it_value
> >>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
> >>>> +  return 0;
> >>>> +#endif
> >>>> +}
> >>>> +
> >>>> +#if __TIMESIZE != 64
> >>>> +libc_hidden_def (__getitimer64)
> >>>> +int
> >>>> +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
> >>>> +{
> >>>> +  struct __itimerval64 val64;
> >>>> +
> >>>> +  val64.it_interval
> >>>> +    = valid_timeval_to_timeval64 (curr_value->it_interval);
> >>>> +  val64.it_value
> >>>> +    = valid_timeval_to_timeval64 (curr_value->it_value);
> >>>> +
> >>>> +  return __getitimer64 (which, &val64);
> >>>> +}
> >>>> +#endif
> >>>> +weak_alias (__getitimer, getitimer)
> >>>
> >>> __getitimer treats curr_value as input-only variable, while it's an
> >>> output-only one in __getitimer64.  This won't work.
> >>
> >> I'm not sure what you mean here, can you please elaborate?
> >
> > __getitimer (…, &curr_value) will never write to curr_value (or do
> > anything useful with it at all); while
> > __getitimer64 (…, &curr_value) will write to curr_value as expected.
> >
> > Conversion in __getitimer shold be in opposite direction and after
> > __getitimer64 call.
> >
>
> Indeed, it should be:
>
>   int
>   __getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
>   {
>     [...]
>   }
>
>   #if __TIMESIZE != 64
>   libc_hidden_def (__getitimer64)
>
>   int
>   __getitimer (__itimer_which_t which, struct itimerval *curr_value)
>   {
>     struct __itimerval64 val64;
>     if (__getitimer64 (which, &val64) != 0)
>       return -1;
>
>     curr_value->it_interval
>       = valid_timeval64_to_timeval (val64->it_interval);
>     curr_value->it_value
>       = valid_timeval64_to_timeval (val64->it_value);
>
>     return 0;
>   }
>   #endif

I changed it to this (which is very similar to above). Good catch on that.

#if __TIMESIZE != 64
libc_hidden_def (__getitimer64)
int
__getitimer (__itimer_which_t which, struct itimerval *curr_value)
{
  struct __itimerval64 val64;
  int ret = __getitimer64 (which, &val64);

  if (ret == 0 && curr_value)
    {
      curr_value->it_interval
        = valid_timeval64_to_timeval (val64.it_interval);
      curr_value->it_value
        = valid_timeval64_to_timeval (val64.it_value);
    }

  return ret;
}

Alistair
Alistair Francis March 30, 2020, 4:27 p.m. UTC | #6 
On Mon, Mar 30, 2020 at 9:34 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 30/03/2020 13:17, Alistair Francis wrote:
> > On Mon, Mar 30, 2020 at 7:49 AM Adhemerval Zanella via Libc-alpha
> > <libc-alpha@sourceware.org> wrote:
> >>
> >>
> >>
> >> On 29/03/2020 19:19, Stepan Golosunov wrote:
> >>> 29.03.2020 в 11:17:17 -0700 Alistair Francis написал:
> >>>> On Sun, Mar 29, 2020 at 2:59 AM Stepan Golosunov <stepan@golosunov.pp.ru> wrote:
> >>>>>
> >>>>> 28.03.2020 в 08:22:46 -0700 Alistair Francis написал:
> >>>>>> --- /dev/null
> >>>>>> +++ b/sysdeps/unix/sysv/linux/getitimer.c
> >>>>>
> >>>>>> +int
> >>>>>> +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
> >>>>>> +{
> >>>>>> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
> >>>>>> +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
> >>>>>> +#else
> >>>>>> +  struct __itimerval32 curr_value_32;
> >>>>>> +
> >>>>>> +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
> >>>>>> +    return -1;
> >>>>>> +
> >>>>>> +  curr_value->it_interval
> >>>>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
> >>>>>> +  curr_value->it_value
> >>>>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
> >>>>>> +  return 0;
> >>>>>> +#endif
> >>>>>> +}
> >>>>>> +
> >>>>>> +#if __TIMESIZE != 64
> >>>>>> +libc_hidden_def (__getitimer64)
> >>>>>> +int
> >>>>>> +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
> >>>>>> +{
> >>>>>> +  struct __itimerval64 val64;
> >>>>>> +
> >>>>>> +  val64.it_interval
> >>>>>> +    = valid_timeval_to_timeval64 (curr_value->it_interval);
> >>>>>> +  val64.it_value
> >>>>>> +    = valid_timeval_to_timeval64 (curr_value->it_value);
> >>>>>> +
> >>>>>> +  return __getitimer64 (which, &val64);
> >>>>>> +}
> >>>>>> +#endif
> >>>>>> +weak_alias (__getitimer, getitimer)
> >>>>>
> >>>>> __getitimer treats curr_value as input-only variable, while it's an
> >>>>> output-only one in __getitimer64.  This won't work.
> >>>>
> >>>> I'm not sure what you mean here, can you please elaborate?
> >>>
> >>> __getitimer (…, &curr_value) will never write to curr_value (or do
> >>> anything useful with it at all); while
> >>> __getitimer64 (…, &curr_value) will write to curr_value as expected.
> >>>
> >>> Conversion in __getitimer shold be in opposite direction and after
> >>> __getitimer64 call.
> >>>
> >>
> >> Indeed, it should be:
> >>
> >>   int
> >>   __getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
> >>   {
> >>     [...]
> >>   }
> >>
> >>   #if __TIMESIZE != 64
> >>   libc_hidden_def (__getitimer64)
> >>
> >>   int
> >>   __getitimer (__itimer_which_t which, struct itimerval *curr_value)
> >>   {
> >>     struct __itimerval64 val64;
> >>     if (__getitimer64 (which, &val64) != 0)
> >>       return -1;
> >>
> >>     curr_value->it_interval
> >>       = valid_timeval64_to_timeval (val64->it_interval);
> >>     curr_value->it_value
> >>       = valid_timeval64_to_timeval (val64->it_value);
> >>
> >>     return 0;
> >>   }
> >>   #endif
> >
> > I changed it to this (which is very similar to above). Good catch on that.
> >
> > #if __TIMESIZE != 64
> > libc_hidden_def (__getitimer64)
> > int
> > __getitimer (__itimer_which_t which, struct itimerval *curr_value)
> > {
> >   struct __itimerval64 val64;
> >   int ret = __getitimer64 (which, &val64);
>
> There is no need to actually check the return value, POSIX states it
> return -1 on failure (and __getitimer64 will set errno accordingly).
>
> >
> >   if (ret == 0 && curr_value)
>
> Again there is no need to check if 'curr_value', neither POSIX or
> kernels add such constraints (and kernel does return EFAULT in
> such case).

We don't pass curr_value to the kernel, so this will just segfault if
curr_value is invalid.

I will remove the check though.

Alistair

>
> >     {
> >       curr_value->it_interval
> >         = valid_timeval64_to_timeval (val64.it_interval);
> >       curr_value->it_value
> >         = valid_timeval64_to_timeval (val64.it_value);
> >     }
> >
> >   return ret;
>
Adhemerval Zanella March 30, 2020, 4:34 p.m. UTC | #7 
On 30/03/2020 13:17, Alistair Francis wrote:
> On Mon, Mar 30, 2020 at 7:49 AM Adhemerval Zanella via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
>>
>>
>>
>> On 29/03/2020 19:19, Stepan Golosunov wrote:
>>> 29.03.2020 в 11:17:17 -0700 Alistair Francis написал:
>>>> On Sun, Mar 29, 2020 at 2:59 AM Stepan Golosunov <stepan@golosunov.pp.ru> wrote:
>>>>>
>>>>> 28.03.2020 в 08:22:46 -0700 Alistair Francis написал:
>>>>>> --- /dev/null
>>>>>> +++ b/sysdeps/unix/sysv/linux/getitimer.c
>>>>>
>>>>>> +int
>>>>>> +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
>>>>>> +{
>>>>>> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
>>>>>> +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
>>>>>> +#else
>>>>>> +  struct __itimerval32 curr_value_32;
>>>>>> +
>>>>>> +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
>>>>>> +    return -1;
>>>>>> +
>>>>>> +  curr_value->it_interval
>>>>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
>>>>>> +  curr_value->it_value
>>>>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
>>>>>> +  return 0;
>>>>>> +#endif
>>>>>> +}
>>>>>> +
>>>>>> +#if __TIMESIZE != 64
>>>>>> +libc_hidden_def (__getitimer64)
>>>>>> +int
>>>>>> +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
>>>>>> +{
>>>>>> +  struct __itimerval64 val64;
>>>>>> +
>>>>>> +  val64.it_interval
>>>>>> +    = valid_timeval_to_timeval64 (curr_value->it_interval);
>>>>>> +  val64.it_value
>>>>>> +    = valid_timeval_to_timeval64 (curr_value->it_value);
>>>>>> +
>>>>>> +  return __getitimer64 (which, &val64);
>>>>>> +}
>>>>>> +#endif
>>>>>> +weak_alias (__getitimer, getitimer)
>>>>>
>>>>> __getitimer treats curr_value as input-only variable, while it's an
>>>>> output-only one in __getitimer64.  This won't work.
>>>>
>>>> I'm not sure what you mean here, can you please elaborate?
>>>
>>> __getitimer (…, &curr_value) will never write to curr_value (or do
>>> anything useful with it at all); while
>>> __getitimer64 (…, &curr_value) will write to curr_value as expected.
>>>
>>> Conversion in __getitimer shold be in opposite direction and after
>>> __getitimer64 call.
>>>
>>
>> Indeed, it should be:
>>
>>   int
>>   __getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
>>   {
>>     [...]
>>   }
>>
>>   #if __TIMESIZE != 64
>>   libc_hidden_def (__getitimer64)
>>
>>   int
>>   __getitimer (__itimer_which_t which, struct itimerval *curr_value)
>>   {
>>     struct __itimerval64 val64;
>>     if (__getitimer64 (which, &val64) != 0)
>>       return -1;
>>
>>     curr_value->it_interval
>>       = valid_timeval64_to_timeval (val64->it_interval);
>>     curr_value->it_value
>>       = valid_timeval64_to_timeval (val64->it_value);
>>
>>     return 0;
>>   }
>>   #endif
> 
> I changed it to this (which is very similar to above). Good catch on that.
> 
> #if __TIMESIZE != 64
> libc_hidden_def (__getitimer64)
> int
> __getitimer (__itimer_which_t which, struct itimerval *curr_value)
> {
>   struct __itimerval64 val64;
>   int ret = __getitimer64 (which, &val64);

There is no need to actually check the return value, POSIX states it
return -1 on failure (and __getitimer64 will set errno accordingly).

> 
>   if (ret == 0 && curr_value)

Again there is no need to check if 'curr_value', neither POSIX or
kernels add such constraints (and kernel does return EFAULT in
such case).

>     {
>       curr_value->it_interval
>         = valid_timeval64_to_timeval (val64.it_interval);
>       curr_value->it_value
>         = valid_timeval64_to_timeval (val64.it_value);
>     }
> 
>   return ret;
Adhemerval Zanella March 30, 2020, 4:44 p.m. UTC | #8 
On 30/03/2020 13:27, Alistair Francis wrote:
> On Mon, Mar 30, 2020 at 9:34 AM Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
>>
>>
>>
>> On 30/03/2020 13:17, Alistair Francis wrote:
>>> On Mon, Mar 30, 2020 at 7:49 AM Adhemerval Zanella via Libc-alpha
>>> <libc-alpha@sourceware.org> wrote:
>>>>
>>>>
>>>>
>>>> On 29/03/2020 19:19, Stepan Golosunov wrote:
>>>>> 29.03.2020 в 11:17:17 -0700 Alistair Francis написал:
>>>>>> On Sun, Mar 29, 2020 at 2:59 AM Stepan Golosunov <stepan@golosunov.pp.ru> wrote:
>>>>>>>
>>>>>>> 28.03.2020 в 08:22:46 -0700 Alistair Francis написал:
>>>>>>>> --- /dev/null
>>>>>>>> +++ b/sysdeps/unix/sysv/linux/getitimer.c
>>>>>>>
>>>>>>>> +int
>>>>>>>> +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
>>>>>>>> +{
>>>>>>>> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
>>>>>>>> +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
>>>>>>>> +#else
>>>>>>>> +  struct __itimerval32 curr_value_32;
>>>>>>>> +
>>>>>>>> +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
>>>>>>>> +    return -1;
>>>>>>>> +
>>>>>>>> +  curr_value->it_interval
>>>>>>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
>>>>>>>> +  curr_value->it_value
>>>>>>>> +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
>>>>>>>> +  return 0;
>>>>>>>> +#endif
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +#if __TIMESIZE != 64
>>>>>>>> +libc_hidden_def (__getitimer64)
>>>>>>>> +int
>>>>>>>> +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
>>>>>>>> +{
>>>>>>>> +  struct __itimerval64 val64;
>>>>>>>> +
>>>>>>>> +  val64.it_interval
>>>>>>>> +    = valid_timeval_to_timeval64 (curr_value->it_interval);
>>>>>>>> +  val64.it_value
>>>>>>>> +    = valid_timeval_to_timeval64 (curr_value->it_value);
>>>>>>>> +
>>>>>>>> +  return __getitimer64 (which, &val64);
>>>>>>>> +}
>>>>>>>> +#endif
>>>>>>>> +weak_alias (__getitimer, getitimer)
>>>>>>>
>>>>>>> __getitimer treats curr_value as input-only variable, while it's an
>>>>>>> output-only one in __getitimer64.  This won't work.
>>>>>>
>>>>>> I'm not sure what you mean here, can you please elaborate?
>>>>>
>>>>> __getitimer (…, &curr_value) will never write to curr_value (or do
>>>>> anything useful with it at all); while
>>>>> __getitimer64 (…, &curr_value) will write to curr_value as expected.
>>>>>
>>>>> Conversion in __getitimer shold be in opposite direction and after
>>>>> __getitimer64 call.
>>>>>
>>>>
>>>> Indeed, it should be:
>>>>
>>>>   int
>>>>   __getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
>>>>   {
>>>>     [...]
>>>>   }
>>>>
>>>>   #if __TIMESIZE != 64
>>>>   libc_hidden_def (__getitimer64)
>>>>
>>>>   int
>>>>   __getitimer (__itimer_which_t which, struct itimerval *curr_value)
>>>>   {
>>>>     struct __itimerval64 val64;
>>>>     if (__getitimer64 (which, &val64) != 0)
>>>>       return -1;
>>>>
>>>>     curr_value->it_interval
>>>>       = valid_timeval64_to_timeval (val64->it_interval);
>>>>     curr_value->it_value
>>>>       = valid_timeval64_to_timeval (val64->it_value);
>>>>
>>>>     return 0;
>>>>   }
>>>>   #endif
>>>
>>> I changed it to this (which is very similar to above). Good catch on that.
>>>
>>> #if __TIMESIZE != 64
>>> libc_hidden_def (__getitimer64)
>>> int
>>> __getitimer (__itimer_which_t which, struct itimerval *curr_value)
>>> {
>>>   struct __itimerval64 val64;
>>>   int ret = __getitimer64 (which, &val64);
>>
>> There is no need to actually check the return value, POSIX states it
>> return -1 on failure (and __getitimer64 will set errno accordingly).
>>
>>>
>>>   if (ret == 0 && curr_value)
>>
>> Again there is no need to check if 'curr_value', neither POSIX or
>> kernels add such constraints (and kernel does return EFAULT in
>> such case).
> 
> We don't pass curr_value to the kernel, so this will just segfault if
> curr_value is invalid.
> 
> I will remove the check though.

I meant that kernels also does not check if the input 'curr_value' is
NULL prior issue copy_to_user.  This might leads to failure in invalid
code that checks for EFAULT (LTP is one that actually has regression
for it), but as for getrlimit change (to call prlimit{64}) we can't
guarantee that EFAULT is generated.
diff mbox series

Patch

diff --git a/include/time.h b/include/time.h
index 2523e0ff0d..4522fe9c4f 100644
--- a/include/time.h
+++ b/include/time.h
@@ -6,6 +6,7 @@ 
 # include <bits/types/locale_t.h>
 # include <stdbool.h>
 # include <time/mktime-internal.h>
+# include <sys/time.h>
 # include <endian.h>
 # include <time-clockid.h>
 # include <sys/time.h>
@@ -127,6 +128,20 @@  struct __itimerval64
 };
 #endif
 
+#if __TIMESIZE == 64
+# define __getitimer64 __getitimer
+# define __setitimer64 __setitimer
+#else
+extern int __getitimer64 (enum __itimer_which __which,
+                          struct __itimerval64 *__value);
+
+libc_hidden_proto (__getitimer64)
+extern int __setitimer64 (enum __itimer_which __which,
+                          const struct __itimerval64 *__restrict __new,
+                          struct __itimerval64 *__restrict __old);
+libc_hidden_proto (__setitimer64)
+#endif
+
 #if __TIMESIZE == 64
 # define __ctime64 ctime
 #else
diff --git a/sysdeps/unix/syscalls.list b/sysdeps/unix/syscalls.list
index e28e801c7a..d249049d6e 100644
--- a/sysdeps/unix/syscalls.list
+++ b/sysdeps/unix/syscalls.list
@@ -25,7 +25,6 @@  getgid		-	getgid		Ei:	__getgid	getgid
 getgroups	-	getgroups	i:ip	__getgroups	getgroups
 gethostid	-	gethostid	i:	gethostid
 gethostname	-	gethostname	i:bn	__gethostname	gethostname
-getitimer	-	getitimer	i:ip	__getitimer	getitimer
 getpeername	-	getpeername	i:ibN	__getpeername	getpeername
 getpid		-	getpid		Ei:	__getpid	getpid
 getpriority	-	getpriority	i:ii	__getpriority	getpriority
@@ -67,7 +66,6 @@  setgid		-	setgid		i:i	__setgid	setgid
 setgroups	-	setgroups	i:ip	setgroups
 sethostid	-	sethostid	i:i	sethostid
 sethostname	-	sethostname	i:pi	sethostname
-setitimer	-	setitimer	i:ipp	__setitimer	setitimer
 setpgid		-	setpgrp		i:ii	__setpgid	setpgid
 setpriority	-	setpriority	i:iii	__setpriority	setpriority
 setregid	-	setregid	i:ii	__setregid	setregid
diff --git a/sysdeps/unix/sysv/linux/getitimer.c b/sysdeps/unix/sysv/linux/getitimer.c
new file mode 100644
index 0000000000..7f678042fd
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/getitimer.c
@@ -0,0 +1,59 @@ 
+/* getitimer -- Get the state of an interval timer.  Linux/32 version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <time.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sysdep.h>
+#include <tv32-compat.h>
+
+int
+__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
+{
+#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
+  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
+#else
+  struct __itimerval32 curr_value_32;
+
+  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
+    return -1;
+
+  curr_value->it_interval
+    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
+  curr_value->it_value
+    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
+  return 0;
+#endif
+}
+
+#if __TIMESIZE != 64
+libc_hidden_def (__getitimer64)
+int
+__getitimer (__itimer_which_t which, struct itimerval *curr_value)
+{
+  struct __itimerval64 val64;
+
+  val64.it_interval
+    = valid_timeval_to_timeval64 (curr_value->it_interval);
+  val64.it_value
+    = valid_timeval_to_timeval64 (curr_value->it_value);
+
+  return __getitimer64 (which, &val64);
+}
+#endif
+weak_alias (__getitimer, getitimer)
diff --git a/sysdeps/unix/sysv/linux/setitimer.c b/sysdeps/unix/sysv/linux/setitimer.c
new file mode 100644
index 0000000000..c7597dfbd3
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/setitimer.c
@@ -0,0 +1,94 @@ 
+/* setitimer -- Set the state of an interval timer.  Linux/32 version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <time.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sysdep.h>
+#include <tv32-compat.h>
+
+int
+__setitimer64 (__itimer_which_t which,
+               const struct __itimerval64 *restrict new_value,
+               struct __itimerval64 *restrict old_value)
+{
+#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
+  return INLINE_SYSCALL_CALL (setitimer, which, new_value, old_value);
+#else
+  struct __itimerval32 new_value_32;
+
+  if (! in_time_t_range (new_value->it_interval.tv_sec))
+  {
+    __set_errno (EOVERFLOW);
+    return -1;
+  }
+  new_value_32.it_interval
+    = valid_timeval64_to_timeval32 (new_value->it_interval);
+
+  if (! in_time_t_range (new_value->it_value.tv_sec))
+  {
+    __set_errno (EOVERFLOW);
+    return -1;
+  }
+  new_value_32.it_value
+    = valid_timeval64_to_timeval32 (new_value->it_value);
+
+  if (old_value == NULL)
+    return INLINE_SYSCALL_CALL (setitimer, which, &new_value_32, NULL);
+
+  struct __itimerval32 old_value_32;
+  if (INLINE_SYSCALL_CALL (setitimer, which, &new_value_32, &old_value_32) == -1)
+    return -1;
+
+  old_value->it_interval
+     = valid_timeval32_to_timeval64 (old_value_32.it_interval);
+  old_value->it_value
+     = valid_timeval32_to_timeval64 (old_value_32.it_value);
+  return 0;
+#endif
+}
+
+#if __TIMESIZE != 64
+libc_hidden_def (__setitimer64)
+int
+__setitimer (__itimer_which_t which,
+             const struct itimerval *restrict new_value,
+             struct itimerval *restrict old_value)
+{
+  int ret;
+  struct __itimerval64 new64, old64;
+
+  new64.it_interval
+    = valid_timeval_to_timeval64 (new_value->it_interval);
+  new64.it_value
+    = valid_timeval_to_timeval64 (new_value->it_value);
+
+  ret = __setitimer64 (which, &new64, old_value ? &old64 : NULL);
+
+  if (ret == 0 && old_value)
+    {
+      old_value->it_interval
+        = valid_timeval64_to_timeval (old64.it_interval);
+      old_value->it_value
+        = valid_timeval64_to_timeval (old64.it_value);
+    }
+
+  return ret;
+}
+#endif
+weak_alias (__setitimer, setitimer)
diff --git a/sysdeps/unix/sysv/linux/tv32-compat.h b/sysdeps/unix/sysv/linux/tv32-compat.h
new file mode 100644
index 0000000000..061a3539e2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tv32-compat.h
@@ -0,0 +1,31 @@ 
+/* Compatibility definitions for 'struct timeval' with 32-bit time_t.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _TV32_COMPAT_H
+#define _TV32_COMPAT_H 1
+
+#include <bits/types/time_t.h>
+
+/* Structures containing 'struct timeval' with 32-bit time_t.  */
+struct __itimerval32
+{
+  struct __timeval32 it_interval;
+  struct __timeval32 it_value;
+};
+
+#endif /* tv32-compat.h */