diff options
| author | Nathan Lynch <nathan_lynch@mentor.com> | 2014-09-11 02:49:08 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-10-13 15:41:07 +0200 |
| commit | 3443c6fd1de2485cbd3e94ac35e54586a8ecc69f (patch) | |
| tree | a21a9b94f871cedc5d9680f31e5f22b65d144820 /arch/arm/kernel/traps.c | |
| parent | 132f8be98a83c38b1c63a8962ce63c31e28fd763 (diff) | |
ARM: 8148/1: flush TLS and thumbee register state during exec
commit fbfb872f5f417cea48760c535e0ff027c88b507a upstream.
The TPIDRURO and TPIDRURW registers need to be flushed during exec;
otherwise TLS information is potentially leaked. TPIDRURO in
particular needs careful treatment. Since flush_thread basically
needs the same code used to set the TLS in arm_syscall, pull that into
a common set_tls helper in tls.h and use it in both places.
Similarly, TEEHBR needs to be cleared during exec as well. Clearing
its save slot in thread_info isn't right as there is no guarantee
that a thread switch will occur before the new program runs. Just
setting the register directly is sufficient.
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'arch/arm/kernel/traps.c')
| -rw-r--r-- | arch/arm/kernel/traps.c | 17 |
1 files changed, 1 insertions, 16 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 1f735aafd5ec..a8dd111ff99a 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -571,7 +571,6 @@ do_cache_op(unsigned long start, unsigned long end, int flags) #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) asmlinkage int arm_syscall(int no, struct pt_regs *regs) { - struct thread_info *thread = current_thread_info(); siginfo_t info; if ((no >> 16) != (__ARM_NR_BASE>> 16)) @@ -622,21 +621,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs) return regs->ARM_r0; case NR(set_tls): - thread->tp_value[0] = regs->ARM_r0; - if (tls_emu) - return 0; - if (has_tls_reg) { - asm ("mcr p15, 0, %0, c13, c0, 3" - : : "r" (regs->ARM_r0)); - } else { - /* - * User space must never try to access this directly. - * Expect your app to break eventually if you do so. - * The user helper at 0xffff0fe0 must be used instead. - * (see entry-armv.S for details) - */ - *((unsigned int *)0xffff0ff0) = regs->ARM_r0; - } + set_tls(regs->ARM_r0); return 0; #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |