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authorRoland McGrath <roland@gnu.org>2003-09-23 12:06:48 +0000
committerRoland McGrath <roland@gnu.org>2003-09-23 12:06:48 +0000
commitecdeaac05f73c29eca92eecd55ad4fb8513c7771 (patch)
treee0cc585c839b68bc3e698f09d51c1f0b78c3cbef /elf/dl-load.c
parent1deb5779e249255d4247529facd65025c1787cd1 (diff)
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2003-09-23 Roland McGrath <roland@redhat.com>
* sysdeps/generic/ldsodefs.h (struct rtld_global): Add _dl_stack_flags and _dl_make_stack_executable_hook. Declare _dl_make_stack_executable. * elf/rtld.c (_rtld_global): Add initializer for _dl_stack_flags. (dl_main): Reset _dl_stack_flags according to PT_GNU_STACK phdr. Initialize _dl_make_stack_executable_hook. * elf/dl-support.c: Define those new variables. (_dl_non_dynamic_init): Scan phdrs for PT_GNU_STACK. (_dl_phdr): Fix type. * elf/dl-load.c (_dl_map_object_from_fd): Grok PT_GNU_STACK phdr and enable execute permission for the stack if necessary. * sysdeps/generic/dl-execstack.c: New file. * elf/Makefile (dl-routines): Add it. * elf/Versions (ld: GLIBC_PRIVATE): Add _dl_make_stack_executable. * sysdeps/unix/sysv/linux/dl-execstack.c: New file.
Diffstat (limited to 'elf/dl-load.c')
-rw-r--r--elf/dl-load.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 249ef84..0b6e96f 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -904,6 +904,9 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
}
}
+ /* Presumed absent PT_GNU_STACK. */
+ uint_fast16_t stack_flags = PF_R|PF_W|PF_X;
+
{
/* Scan the program header table, collecting its load commands. */
struct loadcmd
@@ -1058,6 +1061,10 @@ cannot allocate TLS data structures for initial thread");
errstring = N_("cannot handle TLS data");
goto call_lose;
break;
+
+ case PT_GNU_STACK:
+ stack_flags = ph->p_flags;
+ break;
}
if (__builtin_expect (nloadcmds == 0, 0))
@@ -1334,6 +1341,19 @@ cannot allocate TLS data structures for initial thread");
l->l_dev = st.st_dev;
l->l_ino = st.st_ino;
+ if (__builtin_expect ((stack_flags &~ GL(dl_stack_flags)) & PF_X, 0))
+ {
+ /* The stack is presently not executable, but this module
+ requires that it be executable. */
+ errval = (*GL(dl_make_stack_executable_hook)) ();
+ if (errval)
+ {
+ errstring = N_("\
+cannot enable executable stack as shared object requires");
+ goto call_lose;
+ }
+ }
+
/* When we profile the SONAME might be needed for something else but
loading. Add it right away. */
if (__builtin_expect (GL(dl_profile) != NULL, 0)