Patchwork RFC: tunables failure indications...

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Submitter DJ Delorie
Date Dec. 13, 2019, 6:48 p.m.
Message ID <xnr218qcxw.fsf@greed.delorie.com>
Download mbox | patch
Permalink /patch/36836/
State New
Headers show

Comments

DJ Delorie - Dec. 13, 2019, 6:48 p.m.
?

From d64d1ddf3d79a1e51612f8e4ae3ecfd020246275 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
Carlos O'Donell - Dec. 13, 2019, 8:14 p.m.
On 12/13/19 1:48 PM, DJ Delorie wrote:
> 
> ?
> 

Almost. _dl_fatal_printf is noreturn and calls _exit (127).

So all you need is the call to _dl_fatal_printf.

> From d64d1ddf3d79a1e51612f8e4ae3ecfd020246275 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
> 
> 
> diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
> index e625ac1a7d..3a3f8096c2 100644
> --- a/elf/dl-tunables.c
> +++ b/elf/dl-tunables.c
> @@ -45,12 +45,14 @@ 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");
> +      _exit (1);
> +    }
>  
>    i--;
>  
>

Patch

diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
index e625ac1a7d..3a3f8096c2 100644
--- a/elf/dl-tunables.c
+++ b/elf/dl-tunables.c
@@ -45,12 +45,14 @@  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");
+      _exit (1);
+    }
 
   i--;