From d5873c6e794d8bd9e68c3675341b80c91030ebae Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 22 Jul 2019 14:02:40 +0200 Subject: nptl: Use uintptr_t for address diagnostic in nptl/tst-pthread-getattr MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. --- ChangeLog | 6 ++++++ nptl/tst-pthread-getattr.c | 11 +++++------ 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/ChangeLog b/ChangeLog index c6dbb2e817..e30cf048b6 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2019-07-22 Florian Weimer + + * nptl/tst-pthread-getattr.c (allocate_and_test): Change return + type to uintptr_t. + (check_stack_top): Adjust. + 2019-07-22 Florian Weimer * sysdeps/unix/sysv/linux/bits/socket.h [__USE_MISC]: Include diff --git a/nptl/tst-pthread-getattr.c b/nptl/tst-pthread-getattr.c index a954778767..e3634ea0a7 100644 --- a/nptl/tst-pthread-getattr.c +++ b/nptl/tst-pthread-getattr.c @@ -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; } -- cgit v1.2.3