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| author | Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> | 2012-01-28 13:42:35 +0200 |
|---|---|---|
| committer | Pekka Enberg <penberg@kernel.org> | 2012-01-28 22:19:45 +0200 |
| commit | 2ffd5b493019fe4e7aa8e2c7b948203291af6a84 (patch) | |
| tree | 6ac9bb4333214fb39cf38ea170b7b04ebbf0ebbe | |
| parent | 1cf0e537d09d5b50a1d94c026871c234bcc982d3 (diff) | |
| download | jato-2ffd5b493019fe4e7aa8e2c7b948203291af6a84.tar.gz | |
x86-64: use %rbp instead of %rsp to retrieve *this for locking
Using %rsp to get *this seems fragile, we can look it up relative to
%rbp if we know the frame size and the stack layout used by prologs.
Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
| -rw-r--r-- | arch/x86/emit_64.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/emit_64.c b/arch/x86/emit_64.c index b150f499..f7ec81ea 100644 --- a/arch/x86/emit_64.c +++ b/arch/x86/emit_64.c @@ -1399,7 +1399,9 @@ void emit_unlock(struct buffer *buf, struct vm_object *obj) void emit_lock_this(struct buffer *buf, unsigned long frame_size) { - __emit64_mov_membase_reg(buf, MACH_REG_RSP, 0x00, MACH_REG_RDI); + unsigned long this_offset = frame_size + 8 * NR_CALLEE_SAVE_REGS + 8; + + __emit64_mov_membase_reg(buf, MACH_REG_RBP, - this_offset, MACH_REG_RDI); emit_save_regparm(buf); __emit_call(buf, vm_object_lock); emit_restore_regparm(buf); @@ -1411,7 +1413,9 @@ void emit_lock_this(struct buffer *buf, unsigned long frame_size) void emit_unlock_this(struct buffer *buf, unsigned long frame_size) { - __emit64_mov_membase_reg(buf, MACH_REG_RSP, 0x00, MACH_REG_RDI); + unsigned long this_offset = frame_size + 8 * NR_CALLEE_SAVE_REGS + 8; + + __emit64_mov_membase_reg(buf, MACH_REG_RBP, - this_offset, MACH_REG_RDI); __emit_push_reg(buf, MACH_REG_RAX); emit_save_regparm(buf); __emit_call(buf, vm_object_unlock); |