RFC: tunables failure indications...
Commit Message
"Carlos O'Donell" <codonell@redhat.com> writes:
> Almost. _dl_fatal_printf is noreturn and calls _exit (127).
Done.
From b50d6a577bf2f118923ce0e1b159c4d659815405 Mon Sep 17 00:00:00 2001
From: DJ Delorie <dj@redhat.com>
Date: Fri, 13 Dec 2019 13:36:58 -0500
Subject: tunables: report sbrk() failure
Comments
On 12/13/19 3:21 PM, DJ Delorie wrote:
> "Carlos O'Donell" <codonell@redhat.com> writes:
>> Almost. _dl_fatal_printf is noreturn and calls _exit (127).
>
> Done.
>
> From b50d6a577bf2f118923ce0e1b159c4d659815405 Mon Sep 17 00:00:00 2001
> From: DJ Delorie <dj@redhat.com>
> Date: Fri, 13 Dec 2019 13:36:58 -0500
> Subject: tunables: report sbrk() failure
>
LGTM for master if you proved this works by using gdb to set out to void
and confirmed it exits with the right error code and exits via _exit
(had a breakpoint on _exit and it triggers without showing exit on the
call chain).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
> index e625ac1a7d..f0d7d42770 100644
> --- a/elf/dl-tunables.c
> +++ b/elf/dl-tunables.c
> @@ -45,12 +45,11 @@ tunables_strdup (const char *in)
> while (in[i++] != '\0');
> char *out = __sbrk (i);
>
> - /* FIXME: In reality if the allocation fails, __sbrk will crash attempting to
> - set the thread-local errno since the TCB has not yet been set up. This
> - needs to be fixed with an __sbrk implementation that does not set
> - errno. */
> + /* For most of the tunables code, we ignore user errors. However,
> + this is a system error - and running out of memory at program
> + startup should be reported, so we do. */
> if (out == (void *)-1)
> - return NULL;
> + _dl_fatal_printf ("sbrk() failure while processing tunables\n");
>
> i--;
>
>
@@ -45,12 +45,11 @@ tunables_strdup (const char *in)
while (in[i++] != '\0');
char *out = __sbrk (i);
- /* FIXME: In reality if the allocation fails, __sbrk will crash attempting to
- set the thread-local errno since the TCB has not yet been set up. This
- needs to be fixed with an __sbrk implementation that does not set
- errno. */
+ /* For most of the tunables code, we ignore user errors. However,
+ this is a system error - and running out of memory at program
+ startup should be reported, so we do. */
if (out == (void *)-1)
- return NULL;
+ _dl_fatal_printf ("sbrk() failure while processing tunables\n");
i--;