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authorWill Newton <will.newton@linaro.org>2013-12-10 16:26:38 +0000
committerWill Newton <will.newton@linaro.org>2014-01-14 14:02:34 +0000
commit2f10c4d6901e7a4c4ad294cc5bb8ece6547f4f62 (patch)
tree9694325d2c26b777f46a0e6b68eedc818b731896 /ports/sysdeps/unix
parent497b1e69f9ad6d11341735d81b7c9181d168df90 (diff)
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ARM: Don't apply pointer encryption to the frame pointer
The frame pointer register is rarely used for that purpose on ARM and
applications that look at the contents of the jmp_buf may be relying
on reading an unencrypted value. For example, Ruby uses the contents
of jmp_buf to find the root set for garbage collection so relies on
this pointer value being unencrypted. Without this patch the Ruby
testsuite fails with a segmentation fault.

ports/ChangeLog.arm:

2013-01-14  Will Newton  <will.newton@linaro.org>

	* sysdeps/arm/__longjmp.S: Don't apply pointer encryption
	to fp register.
	* sysdeps/arm/setjmp.S: Likewise.
	* sysdeps/arm/include/bits/setjmp.h (JMP_BUF_REGLIST): Add
	fp to register list, remove a4.
	* sysdeps/unix/sysv/linux/arm/sysdep.h (PTR_MANGLE_LOAD):
	New macro.
Diffstat (limited to 'ports/sysdeps/unix')
-rw-r--r--ports/sysdeps/unix/sysv/linux/arm/sysdep.h8
1 files changed, 6 insertions, 2 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/arm/sysdep.h b/ports/sysdeps/unix/sysv/linux/arm/sysdep.h
index 11d0a1146e..dcd99198cc 100644
--- a/ports/sysdeps/unix/sysv/linux/arm/sysdep.h
+++ b/ports/sysdeps/unix/sysv/linux/arm/sysdep.h
@@ -439,8 +439,10 @@ __local_syscall_error:						\
 #if (defined NOT_IN_libc && defined IS_IN_rtld) || \
   (!defined SHARED && (!defined NOT_IN_libc || defined IS_IN_libpthread))
 # ifdef __ASSEMBLER__
+#  define PTR_MANGLE_LOAD(guard, tmp)					\
+  LDST_PCREL(ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard_local));
 #  define PTR_MANGLE(dst, src, guard, tmp)				\
-  LDST_PCREL(ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard_local)); \
+  PTR_MANGLE_LOAD(guard, tmp);						\
   PTR_MANGLE2(dst, src, guard)
 /* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
 #  define PTR_MANGLE2(dst, src, guard)		\
@@ -457,8 +459,10 @@ extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden;
 # endif
 #else
 # ifdef __ASSEMBLER__
+#  define PTR_MANGLE_LOAD(guard, tmp)					\
+  LDST_GLOBAL(ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard));
 #  define PTR_MANGLE(dst, src, guard, tmp)				\
-  LDST_GLOBAL(ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard));	\
+  PTR_MANGLE_LOAD(guard, tmp);						\
   PTR_MANGLE2(dst, src, guard)
 /* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
 #  define PTR_MANGLE2(dst, src, guard)		\