Patchwork [RFC,v1,05/16] sysdeps/getrlimit: Use __NR_prlimit64 if avaliable

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Submitter Alistair Francis
Date June 22, 2019, 4:37 a.m.
Message ID <6fb166d85bf67a6d49f64064a84156bd10f63225.1561177967.git.alistair.francis@wdc.com>
Download mbox | patch
Permalink /patch/33266/
State New
Headers show

Comments

Alistair Francis - June 22, 2019, 4:37 a.m.
If the __NR_prlimit64 syscall is avaliable let's use that instead of
__NR_ugetrlimit as it isn't always avaliable (they aren't avaliable
on RV32).

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 ChangeLog                           | 1 +
 sysdeps/unix/sysv/linux/getrlimit.c | 4 ++++
 2 files changed, 5 insertions(+)
arnd@arndb.de - June 23, 2019, 7:47 p.m.
On Sat, Jun 22, 2019 at 6:47 AM Alistair Francis
<alistair.francis@wdc.com> wrote:

> diff --git a/sysdeps/unix/sysv/linux/getrlimit.c b/sysdeps/unix/sysv/linux/getrlimit.c
> index 10c0176619..2917029afd 100644
> --- a/sysdeps/unix/sysv/linux/getrlimit.c
> +++ b/sysdeps/unix/sysv/linux/getrlimit.c
> @@ -35,7 +35,11 @@
>  int
>  __new_getrlimit (enum __rlimit_resource resource, struct rlimit *rlim)
>  {
> +#ifdef __NR_prlimit64
> +  return INLINE_SYSCALL_CALL (prlimit64, 0, resource, rlim, NULL);
> +#else
>    return INLINE_SYSCALL_CALL (ugetrlimit, resource, rlim);
> +#endif
>  }
>  weak_alias (__new_getrlimit, __getrlimit)
>  hidden_weak (__getrlimit)

This breaks all other 32-bit architectures, since glibc traditionally uses
32-bit limits even on architectures that always supported the 64-bit
interface.

      Arnd
Alistair Francis - June 23, 2019, 11:33 p.m.
On Sun, Jun 23, 2019 at 12:48 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Sat, Jun 22, 2019 at 6:47 AM Alistair Francis
> <alistair.francis@wdc.com> wrote:
>
> > diff --git a/sysdeps/unix/sysv/linux/getrlimit.c b/sysdeps/unix/sysv/linux/getrlimit.c
> > index 10c0176619..2917029afd 100644
> > --- a/sysdeps/unix/sysv/linux/getrlimit.c
> > +++ b/sysdeps/unix/sysv/linux/getrlimit.c
> > @@ -35,7 +35,11 @@
> >  int
> >  __new_getrlimit (enum __rlimit_resource resource, struct rlimit *rlim)
> >  {
> > +#ifdef __NR_prlimit64
> > +  return INLINE_SYSCALL_CALL (prlimit64, 0, resource, rlim, NULL);
> > +#else
> >    return INLINE_SYSCALL_CALL (ugetrlimit, resource, rlim);
> > +#endif
> >  }
> >  weak_alias (__new_getrlimit, __getrlimit)
> >  hidden_weak (__getrlimit)
>
> This breaks all other 32-bit architectures, since glibc traditionally uses
> 32-bit limits even on architectures that always supported the 64-bit
> interface.

If we just mask out the high bits will that fix the problem?

Alistair

>
>       Arnd

Patch

diff --git a/ChangeLog b/ChangeLog
index 9ed9bea8b1..1f1070ebc3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -8,6 +8,7 @@ 
 	* sysdeps/unix/sysv/linux/wait.c: Use __NR_waitid if avaliable.
 	* sysdeps/unix/sysv/linux/waitpid.c: Likewise.
 	* sysdeps/unix/sysv/linux/waitpid_nocancel.c: Likewise.
+	* sysdeps/unix/sysv/linux/getrlimit.c: Use __NR_prlimit64 if avaliable
 
 2019-06-20  Dmitry V. Levin  <ldv@altlinux.org>
 	    Florian Weimer  <fweimer@redhat.com>
diff --git a/sysdeps/unix/sysv/linux/getrlimit.c b/sysdeps/unix/sysv/linux/getrlimit.c
index 10c0176619..2917029afd 100644
--- a/sysdeps/unix/sysv/linux/getrlimit.c
+++ b/sysdeps/unix/sysv/linux/getrlimit.c
@@ -35,7 +35,11 @@ 
 int
 __new_getrlimit (enum __rlimit_resource resource, struct rlimit *rlim)
 {
+#ifdef __NR_prlimit64
+  return INLINE_SYSCALL_CALL (prlimit64, 0, resource, rlim, NULL);
+#else
   return INLINE_SYSCALL_CALL (ugetrlimit, resource, rlim);
+#endif
 }
 weak_alias (__new_getrlimit, __getrlimit)
 hidden_weak (__getrlimit)