On Sat, 27 Apr 2024, Michael Schmitz wrote:
diff --git a/arch/m68k/lib/uaccess.c b/arch/m68k/lib/uaccess.c
index 86b6fed5151c..e3ed893047f8 100644
--- a/arch/m68k/lib/uaccess.c
+++ b/arch/m68k/lib/uaccess.c
@@ -62,35 +62,42 @@ unsigned long __generic_copy_to_user(void __user *to, const void *from,
asm volatile ("\n"
" tst.l %0\n"
- " jeq 4f\n"
+ " jeq 5f\n"
"1: move.l (%1)+,%3\n"
"2: "MOVES".l %3,(%2)+\n"
"3: subq.l #1,%0\n"
- " jne 1b\n"
- "4: btst #1,%5\n"
- " jeq 6f\n"
- " move.w (%1)+,%3\n"
- "5: "MOVES".w %3,(%2)+\n"
- "6: btst #0,%5\n"
+ "4: jne 1b\n"
+ "5: btst #1,%5\n"
" jeq 8f\n"
- " move.b (%1)+,%3\n"
- "7: "MOVES".b %3,(%2)+\n"
- "8:\n"
+ "6: move.w (%1)+,%3\n"
+ "7: "MOVES".w %3,(%2)+\n"
+ "8: btst #0,%5\n"
+ "9: jeq 13f\n"
+ "10: move.b (%1)+,%3\n"
+ "11: "MOVES".b %3,(%2)+\n"
+ "12: nop\n"
+ "13:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"20: lsl.l #2,%0\n"
"50: add.l %5,%0\n"
- " jra 8b\n"
+ " jra 13b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
+ " .long 1b,20b\n"
" .long 2b,20b\n"
" .long 3b,20b\n"
- " .long 5b,50b\n"
+ " .long 4b,20b\n"
+ " .long 5b,20b\n"
" .long 6b,50b\n"
I think a fault at 6b has to get fixed up at 20b.
" .long 7b,50b\n"
" .long 8b,50b\n"
+ " .long 9b,50b\n"
+ " .long 10b,50b\n"
+ " .long 11b,50b\n"
+ " .long 12b,50b\n"
" .previous"
: "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
: "0" (n / 4), "d" (n & 3));
@@ -109,32 +116,35 @@ unsigned long __clear_user(void __user *to, unsigned long n)
asm volatile ("\n"
" tst.l %0\n"
- " jeq 3f\n"
+ " jeq 4f\n"
"1: "MOVES".l %2,(%1)+\n"
"2: subq.l #1,%0\n"
- " jne 1b\n"
- "3: btst #1,%4\n"
- " jeq 5f\n"
- "4: "MOVES".w %2,(%1)+\n"
- "5: btst #0,%4\n"
- " jeq 7f\n"
- "6: "MOVES".b %2,(%1)\n"
- "7:\n"
+ "3: jne 1b\n"
+ "4: btst #1,%4\n"
+ " jeq 6f\n"
+ "5: "MOVES".w %2,(%1)+\n"
+ "6: btst #0,%4\n"
+ "7: jeq 9f\n"
+ "8: "MOVES".b %2,(%1)\n"
+ "9:\n"
Should we put a NOP here to avoid having the unknown next instruction
(label 9) in the exception table? We can't actually fix up a fault there
unless by chance it was the MOVES that caused it.
" .section .fixup,\"ax\"\n"
" .even\n"
"10: lsl.l #2,%0\n"
"40: add.l %4,%0\n"
- " jra 7b\n"
+ " jra 9b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,10b\n"
" .long 2b,10b\n"
- " .long 4b,40b\n"
+ " .long 3b,10b\n"
+ " .long 4b,10b\n"
" .long 5b,40b\n"
" .long 6b,40b\n"
" .long 7b,40b\n"
+ " .long 8b,40b\n"
+ " .long 9b,40b\n"
" .previous"
: "=d" (res), "+a" (to)
: "d" (0), "0" (n / 4), "d" (n & 3));
