path: root/include/asm-parisc/uaccess.h
diff options
authorCarlos O'Donell <carlos@parisc-linux.org>2006-04-22 14:47:21 -0600
committerKyle McMartin <kyle@hera.kernel.org>2006-06-27 23:28:33 +0000
commit3fd3a74f45c935f7d6d5c2fb48f06324b18826b7 (patch)
tree552033cbdc4e19b667a25c55e642a172a1ec3b2e /include/asm-parisc/uaccess.h
parent[PARISC] Whitespace clean up in asm/pgtable.h (diff)
[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>
Diffstat (limited to '')
1 files changed, 7 insertions, 2 deletions
diff --git a/include/asm-parisc/uaccess.h b/include/asm-parisc/uaccess.h
index f6c417c8c484..d973e8b3466c 100644
--- a/include/asm-parisc/uaccess.h
+++ b/include/asm-parisc/uaccess.h
@@ -172,7 +172,11 @@ struct exception_data {
* 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 @@ struct exception_data {
"\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__ ( \