AuroraMiddleware/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2024-12-12 14:20:13 +00:00
Code Issues Packages Projects Releases Wiki Activity

nptl: Use uintptr_t for address diagnostic in nptl/tst-pthread-getattr

Browse Source 
Recent GCC versions warn about the attempt to return the address of a
local variable:

tst-pthread-getattr.c: In function ‘allocate_and_test’:
tst-pthread-getattr.c:54:10: error: function returns address of local variable [-Werror=return-local-addr]
   54 |   return mem;
      |          ^~~
In file included from ../include/alloca.h:3,
                 from tst-pthread-getattr.c:26:
../stdlib/alloca.h:35:23: note: declared here
   35 | # define alloca(size) __builtin_alloca (size)
      |                       ^~~~~~~~~~~~~~~~~~~~~~~
tst-pthread-getattr.c:51:9: note: in expansion of macro ‘alloca’
   51 |   mem = alloca ((size_t) (mem - target));
      |         ^~~~~~

The address itself is used in a check in the caller, so using
uintptr_t instead is reasonable.
This commit is contained in:
Florian Weimer 2019-07-22 14:02:40 +02:00
parent c1d1e0c9f2
commit d5873c6e79
2 changed files with 11 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
ChangeLog
View File

@ -1,3 +1,9 @@
2019-07-22 Florian Weimer <fweimer@redhat.com>
* nptl/tst-pthread-getattr.c (allocate_and_test): Change return
type to uintptr_t.
(check_stack_top): Adjust.
2019-07-22 Florian Weimer <fweimer@redhat.com>
* sysdeps/unix/sysv/linux/bits/socket.h [__USE_MISC]: Include

11
nptl/tst-pthread-getattr.c
View File

@ -43,7 +43,7 @@ static size_t pagesize;
/* Check if the page in which TARGET lies is accessible. This will segfault
if it fails. */
static volatile char *
static volatile uintptr_t
allocate_and_test (char *target)
{
volatile char *mem = (char *) &mem;
@ -51,7 +51,7 @@ allocate_and_test (char *target)
mem = alloca ((size_t) (mem - target));
*mem = 42;
return mem;
return (uintptr_t) mem;
}
static int
@ -84,7 +84,6 @@ check_stack_top (void)
{
struct rlimit stack_limit;
void *stackaddr;
volatile void *mem;
size_t stacksize = 0;
int ret;
uintptr_t pagemask = ~(pagesize - 1);
@ -130,14 +129,14 @@ check_stack_top (void)
stack and test access there. It is however sufficient to simply check if
the top page is accessible, so we target our access halfway up the top
page. Thanks Chris Metcalf for this idea. */
mem = allocate_and_test (stackaddr + pagesize / 2);
uintptr_t mem = allocate_and_test (stackaddr + pagesize / 2);
/* Before we celebrate, make sure we actually did test the same page. */
if (((uintptr_t) stackaddr & pagemask) != ((uintptr_t) mem & pagemask))
if (((uintptr_t) stackaddr & pagemask) != (mem & pagemask))
{
printf ("We successfully wrote into the wrong page.\n"
"Expected %#" PRIxPTR ", but got %#" PRIxPTR "\n",
(uintptr_t) stackaddr & pagemask, (uintptr_t) mem & pagemask);
(uintptr_t) stackaddr & pagemask, mem & pagemask);
return 1;
}