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authorAl Viro <viro@zeniv.linux.org.uk>2020-07-13 05:56:34 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2020-08-20 22:45:16 +0300
commit1d60be3c25edf4b9554fdb02aa6fb6fd75695aa7 (patch)
tree4a7c40fc3b387fa5b4c7ae95ba223cf432f55016 /arch/arm/lib
parentb712139543af98a91300c4e923b85d311cc77c44 (diff)
downloadlinux-1d60be3c25edf4b9554fdb02aa6fb6fd75695aa7.tar.xz
arm: propagate the calling convention changes down to csum_partial_copy_from_user()
... and get rid of the "clean the destination on error" crap. Simplifies the fault handlers and the function itself... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/arm/lib')
-rw-r--r--arch/arm/lib/csumpartialcopy.S1
-rw-r--r--arch/arm/lib/csumpartialcopygeneric.S1
-rw-r--r--arch/arm/lib/csumpartialcopyuser.S26
3 files changed, 7 insertions, 21 deletions
diff --git a/arch/arm/lib/csumpartialcopy.S b/arch/arm/lib/csumpartialcopy.S
index aab914fbc86b..1ca6aadd649c 100644
--- a/arch/arm/lib/csumpartialcopy.S
+++ b/arch/arm/lib/csumpartialcopy.S
@@ -16,7 +16,6 @@
.macro save_regs
stmfd sp!, {r1, r4 - r8, lr}
- mov r3, #0
.endm
.macro load_regs
diff --git a/arch/arm/lib/csumpartialcopygeneric.S b/arch/arm/lib/csumpartialcopygeneric.S
index 0b706a39a677..0fd5c10e90a7 100644
--- a/arch/arm/lib/csumpartialcopygeneric.S
+++ b/arch/arm/lib/csumpartialcopygeneric.S
@@ -86,6 +86,7 @@ sum .req r3
FN_ENTRY
save_regs
+ mov sum, #-1
cmp len, #8 @ Ensure that we have at least
blo .Lless8 @ 8 bytes to copy.
diff --git a/arch/arm/lib/csumpartialcopyuser.S b/arch/arm/lib/csumpartialcopyuser.S
index 6bd3a93eaa3c..6928781e6bee 100644
--- a/arch/arm/lib/csumpartialcopyuser.S
+++ b/arch/arm/lib/csumpartialcopyuser.S
@@ -62,9 +62,9 @@
/*
* unsigned int
- * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
- * r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
- * Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
+ * csum_partial_copy_from_user(const char *src, char *dst, int len)
+ * r0 = src, r1 = dst, r2 = len
+ * Returns : r0 = checksum or 0
*/
#define FN_ENTRY ENTRY(csum_partial_copy_from_user)
@@ -73,25 +73,11 @@
#include "csumpartialcopygeneric.S"
/*
- * FIXME: minor buglet here
- * We don't return the checksum for the data present in the buffer. To do
- * so properly, we would have to add in whatever registers were loaded before
- * the fault, which, with the current asm above is not predictable.
+ * We report fault by returning 0 csum - impossible in normal case, since
+ * we start with 0xffffffff for initial sum.
*/
.pushsection .text.fixup,"ax"
.align 4
-9001: mov r4, #-EFAULT
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
- ldr r5, [sp, #9*4] @ *err_ptr
-#else
- ldr r5, [sp, #8*4] @ *err_ptr
-#endif
- str r4, [r5]
- ldmia sp, {r1, r2} @ retrieve dst, len
- add r2, r2, r1
- mov r0, #0 @ zero the buffer
-9002: teq r2, r1
- strbne r0, [r1], #1
- bne 9002b
+9001: mov r0, #0
load_regs
.popsection