The first thing I tried to fix this issue was to use the 'memcpy.S' file from 2.4.7 and that actually worked, but that was a step backwards. It was much simpler to just add a 'nop' after the offending branch instruction. It fixes all of my problems with 'copy_from_user'. I have already checked these into both the 2.4 and 2.5 trees. I do have one further question. In 'arch/mips/mm/fault.c' when we need to do a fixup: fixup = search_exception_table(regs->cp0_epc); Why do we not check to see if the EPC is a branch insn before looking in the exception table? -Steve
Index: memcpy.S =================================================================== RCS file: /home/cvs/linux/arch/mips/lib/memcpy.S,v retrieving revision 1.6.2.4 diff -u -r1.6.2.4 memcpy.S --- memcpy.S 19 Sep 2002 14:01:24 -0000 1.6.2.4 +++ memcpy.S 4 Mar 2003 00:09:52 -0000 @@ -357,6 +357,7 @@ beqz len, done and rem, len, NBYTES-1 # rem = len % NBYTES beq rem, len, copy_bytes + nop 1: EXC( LDFIRST t0, FIRST(0)(src), l_exc) EXC( LDREST t0, REST(0)(src), l_exc_copy)
Index: memcpy.S =================================================================== RCS file: /home/cvs/linux/arch/mips/lib/memcpy.S,v retrieving revision 1.11 diff -u -r1.11 memcpy.S --- memcpy.S 19 Sep 2002 14:01:28 -0000 1.11 +++ memcpy.S 4 Mar 2003 00:10:58 -0000 @@ -357,6 +357,7 @@ beqz len, done and rem, len, NBYTES-1 # rem = len % NBYTES beq rem, len, copy_bytes + nop 1: EXC( LDFIRST t0, FIRST(0)(src), l_exc) EXC( LDREST t0, REST(0)(src), l_exc_copy)
