MIPS: Don't clobber personality high bits.
The high bits of current->personality carry settings that we don't want to
clobber on each exec. Only clobber them if the lower bits that indicate
either PER_LINUX or PER_LINUX32 are invalid.
The clobbering prevents us from using useful bits like ADDR_NO_RANDOMIZE.
Reported-by: Camm Maguire <camm@maguirefamily.org>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: Camm Maguire <camm@maguirefamily.org>
Patchwork: https://patchwork.linux-mips.org/patch/1750/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index fd1d39e..455c0ac 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -249,7 +249,8 @@
#define SET_PERSONALITY(ex) \
do { \
- set_personality(PER_LINUX); \
+ if (personality(current->personality) != PER_LINUX) \
+ set_personality(PER_LINUX); \
\
current->thread.abi = &mips_abi; \
} while (0)
@@ -296,6 +297,8 @@
#define SET_PERSONALITY(ex) \
do { \
+ unsigned int p; \
+ \
clear_thread_flag(TIF_32BIT_REGS); \
clear_thread_flag(TIF_32BIT_ADDR); \
\
@@ -304,7 +307,8 @@
else \
current->thread.abi = &mips_abi; \
\
- if (current->personality != PER_LINUX32) \
+ p = personality(current->personality); \
+ if (p != PER_LINUX32 && p != PER_LINUX) \
set_personality(PER_LINUX); \
} while (0)