From a10aa331aa02e0140e81b31a97b258dae764efcc Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Sun, 4 Nov 2018 01:46:00 -0700 Subject: xtensa: make sure bFLT stack is 16 byte aligned commit 0773495b1f5f1c5e23551843f87b5ff37e7af8f7 upstream. Xtensa ABI requires stack alignment to be at least 16. In noMMU configuration ARCH_SLAB_MINALIGN is used to align stack. Make it at least 16. This fixes the following runtime error in noMMU configuration, caused by interaction between insufficiently aligned stack and alloca function, that results in corruption of on-stack variable in the libc function glob: Caught unhandled exception in 'sh' (pid = 47, pc = 0x02d05d65) - should not happen EXCCAUSE is 15 Cc: stable@vger.kernel.org Signed-off-by: Max Filippov Signed-off-by: Greg Kroah-Hartman --- arch/xtensa/include/asm/processor.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/xtensa') diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h index b42d68bfe3cf..521c1e789e6e 100644 --- a/arch/xtensa/include/asm/processor.h +++ b/arch/xtensa/include/asm/processor.h @@ -24,7 +24,11 @@ # error Linux requires the Xtensa Windowed Registers Option. #endif -#define ARCH_SLAB_MINALIGN XCHAL_DATA_WIDTH +/* Xtensa ABI requires stack alignment to be at least 16 */ + +#define STACK_ALIGN (XCHAL_DATA_WIDTH > 16 ? XCHAL_DATA_WIDTH : 16) + +#define ARCH_SLAB_MINALIGN STACK_ALIGN /* * User space process size: 1 GB. -- cgit v1.2.3