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authorRyan Arnold <ryanarn@etna.rchland.ibm.com>2010-06-11 15:11:10 -0500
committerRyan Arnold <ryanarn@etna.rchland.ibm.com>2010-06-11 15:11:10 -0500
commit91ab06c7447d8e123b6670bc8e595c15c9ed991f (patch)
treebdafad891de236a6791295179f689057639dc855
parent165ab209dffe764f7aea8d6b732f84cf5c0bb02c (diff)
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Experimental patch to default PPC64 to no-execstack support. This will need
to be abstracted to remove the guards from common files and put the stack initialization into a header file that can be overridden. 2010-06-11 Ryan S. Arnold <rsa@us.ibm.com> * elf/dl-load.c (_dl_map_object_from_fd): Set default stack_flags to no-exec for ARCH_PPC64. * elf/dl-support.c [_dl_stack_flags]: Set default stack_flags to no-exec for ARCH_PPC64. * elf/rtld.c (_dl_starting_up): Set default stack_flags to no-exec for ARCH_PPC64.
-rw-r--r--ChangeLog9
-rw-r--r--elf/dl-load.c5
-rw-r--r--elf/dl-support.c7
-rw-r--r--elf/rtld.c5
4 files changed, 26 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 01b1ef6..0e4cdfb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2010-06-11 Ryan S. Arnold <rsa@us.ibm.com>
+
+ * elf/dl-load.c (_dl_map_object_from_fd): Set default stack_flags to
+ no-exec for ARCH_PPC64.
+ * elf/dl-support.c [_dl_stack_flags]: Set default stack_flags to
+ no-exec for ARCH_PPC64.
+ * elf/rtld.c (_dl_starting_up): Set default stack_flags to no-exec for
+ ARCH_PPC64.
+
2010-05-28 Luis Machado <luisgpm@br.ibm.com>
* sysdeps/powerpc/powerpc32/power7/memcpy.S: Exchange srdi for srwi.
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 597193c..ff02fe4 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -996,8 +996,13 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
}
}
+#if (defined (_ARCH_PPC64) || defined (__powerpc64__))
+ /* Default to no-exec stack on PPC64. */
+ uint_fast16_t stack_flags = PF_R|PF_W;
+#else
/* Presumed absent PT_GNU_STACK. */
uint_fast16_t stack_flags = PF_R|PF_W|PF_X;
+#endif
{
/* Scan the program header table, collecting its load commands. */
diff --git a/elf/dl-support.c b/elf/dl-support.c
index bcf0e2a..8d2d616 100644
--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -126,8 +126,15 @@ ElfW(Phdr) *_dl_phdr;
size_t _dl_phnum;
uint64_t _dl_hwcap __attribute__ ((nocommon));
+
+#if (defined (_ARCH_PPC64) || defined (__powerpc64__))
+/* Default to no-exec stack on PPC64. */
+/* Prevailing state of the stack, PF_X indicating it's executable. */
+ElfW(Word) _dl_stack_flags = PF_R|PF_W;
+#else
/* Prevailing state of the stack, PF_X indicating it's executable. */
ElfW(Word) _dl_stack_flags = PF_R|PF_W|PF_X;
+#endif
/* If loading a shared object requires that we make the stack executable
when it was not, we do it by calling this function.
diff --git a/elf/rtld.c b/elf/rtld.c
index 55b84c3..bcaaf90 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -123,7 +123,12 @@ INTVARDEF(_dl_starting_up)
struct rtld_global _rtld_global =
{
/* Default presumption without further information is executable stack. */
+#if (defined (_ARCH_PPC64) || defined (__powerpc64__))
+ /* Default to no-exec stack on PPC64. */
+ ._dl_stack_flags = PF_R|PF_W,
+#else
._dl_stack_flags = PF_R|PF_W|PF_X,
+#endif
#ifdef _LIBC_REENTRANT
._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
#endif