diff options
| -rw-r--r-- | arch/powerpc/lib/copyuser_64.S | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/arch/powerpc/lib/copyuser_64.S b/arch/powerpc/lib/copyuser_64.S index 2197a35097c5..96c514bee66b 100644 --- a/arch/powerpc/lib/copyuser_64.S +++ b/arch/powerpc/lib/copyuser_64.S @@ -379,8 +379,8 @@ stex; stb r0,0(r3) blr /* - * exception handlers for stores: we just need to work - * out how many bytes weren't copied + * exception handlers for stores: we need to work out how many bytes + * weren't copied, and we may need to copy some more. * Note that the number of bytes of instructions for adjusting r3 needs * to equal the amount of the adjustment, due to the trick of using * .Lst_exc - r3_offset as the handler address. @@ -400,10 +400,27 @@ stex; stb r0,0(r3) /* adjust by 4 */ addi r3,r3,4 .Lst_exc: - ld r6,-24(r1) - ld r5,-8(r1) - add r6,r6,r5 - subf r3,r3,r6 /* #bytes not copied in r3 */ + ld r6,-24(r1) /* original destination pointer */ + ld r4,-16(r1) /* original source pointer */ + ld r5,-8(r1) /* original number of bytes */ + add r7,r6,r5 + /* + * If the destination pointer isn't 8-byte aligned, + * we may have got the exception as a result of a + * store that overlapped a page boundary, so we may be + * able to copy a few more bytes. + */ +17: andi. r0,r3,7 + beq 19f + subf r8,r6,r3 /* #bytes copied */ +100: EX_TABLE(100b,19f) + lbzx r0,r8,r4 +100: EX_TABLE(100b,19f) + stb r0,0(r3) + addi r3,r3,1 + cmpld r3,r7 + blt 17b +19: subf r3,r3,r7 /* #bytes not copied in r3 */ blr /* |