[PARISC] Use FIXUP_BRANCH_CLOBBER to asm clobber list
Joel Soete noticed correctly that the fixup's clobbers must be listed
as the ASM clobbers. FIXUP_BRANCH in unaligned.c has a new macro which
lists all the clobbers in the fixup, we use this throughout the file
to simplify the process of listing clobbers in the future.
A missing "r1" clobber is added to our uaccess.h for the 64-bit
__put_kernel_asm. Interestingly this is a pretty serious bug since gcc
generates pretty good use of r1 as a temporary and the uses of
__put_kernel_asm are varied and dangerous if r1 is scratched during
an invalid write.
Signed-off-by: Joel Soete <soete.joel@tiscali.be>
Signed-off-by: Carlos O'Donell <carlos@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
diff --git a/include/asm-parisc/uaccess.h b/include/asm-parisc/uaccess.h
index f6c417c..d973e8b 100644
--- a/include/asm-parisc/uaccess.h
+++ b/include/asm-parisc/uaccess.h
@@ -172,7 +172,11 @@
/*
* The "__put_user/kernel_asm()" macros tell gcc they read from memory
* instead of writing. This is because they do not write to any memory
- * gcc knows about, so there are no aliasing issues.
+ * gcc knows about, so there are no aliasing issues. These macros must
+ * also be aware that "fixup_put_user_skip_[12]" are executed in the
+ * context of the fault, and any registers used there must be listed
+ * as clobbers. In this case only "r1" is used by the current routines.
+ * r8/r9 are already listed as err/val.
*/
#ifdef __LP64__
@@ -183,7 +187,8 @@
"\t.dword\t1b,fixup_put_user_skip_1\n" \
"\t.previous" \
: "=r"(__pu_err) \
- : "r"(ptr), "r"(x), "0"(__pu_err))
+ : "r"(ptr), "r"(x), "0"(__pu_err) \
+ : "r1")
#define __put_user_asm(stx,x,ptr) \
__asm__ __volatile__ ( \