[PATCH 16/18] arm: clarify comment about exception stack use

Andrew Jones
2015-02-01T18:35:16Z

Each mode has its own stack, but we only use it as a base pointer
to a private memory region. That region, which has a size of
sizeof(struct pt_regs), is used to store some registers during the
switch to svc mode - which will use the normal svc stack. The switch
to svc mode is done because we handle all exceptions in svc.

Signed-off-by: Andrew Jones <drjones@redhat.com>
---
arm/cstart.S | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arm/cstart.S b/arm/cstart.S
index fd02aaab268d7..08a0b3ecc61f6 100644
--- a/arm/cstart.S
+++ b/arm/cstart.S
@@ -121,8 +121,9 @@ asm_mmu_enable:
* Simplified version of the Linux kernel implementation
* arch/arm/kernel/entry-armv.S
*
- * Each mode has an S_FRAME_SIZE sized stack initialized
- * in exceptions_init
+ * Each mode has an S_FRAME_SIZE sized memory region,
+ * and the mode's stack pointer has been initialized
+ * to the base of that region in exceptions_init.
*/
.macro vector_stub, name, vec, mode, correction=0
.align 5
--
1.9.3