On Fri, 11 Jun 2004 cgd@xxxxxxxxxxxx wrote:How about the attached (lightly tested) patch?
Unfortunately, at this point, Linux should probably accept the
divide-by-zero code in both locations.
I think that's not a big trouble for Linux -- the path is rare and not critical for performance.
David Daney.
*** ../linux-avtrex/linux/arch/mips/kernel/traps.c 2004-02-26 11:14:09.000000000 -0800
--- arch/mips/kernel/traps.c 2004-06-11 13:43:00.000000000 -0700
***************
*** 597,615 ****
* There is the ancient bug in the MIPS assemblers that the break
* code starts left to bit 16 instead to bit 6 in the opcode.
* Gas is bug-compatible ...
! */
! bcode = ((opcode >> 16) & ((1 << 20) - 1));
!
! /*
* (A short test says that IRIX 5.3 sends SIGTRAP for all break
* insns, even for break codes that indicate arithmetic failures.
* Weird ...)
* But should we continue the brokenness??? --macro
*/
switch (bcode) {
! case 6:
! case 7:
! if (bcode == 7)
info.si_code = FPE_INTDIV;
else
info.si_code = FPE_INTOVF;
--- 597,621 ----
* There is the ancient bug in the MIPS assemblers that the break
* code starts left to bit 16 instead to bit 6 in the opcode.
* Gas is bug-compatible ...
! *
* (A short test says that IRIX 5.3 sends SIGTRAP for all break
* insns, even for break codes that indicate arithmetic failures.
* Weird ...)
* But should we continue the brokenness??? --macro
+ *
+ * It seems some assemblers (binutils-2.15 for example) assemble
+ * break correctly. So we check for the break code in either
+ * position.
+ *
*/
+
+ bcode = ((opcode >> 6) & ((1 << 20) - 1));
switch (bcode) {
! case 0x0006:
! case 0x0007:
! case 0x1800: /* 6 << 10 */
! case 0x1c00: /* 7 << 10 */
! if (bcode == 0x7 || bcode == 0x1c00)
info.si_code = FPE_INTDIV;
else
info.si_code = FPE_INTOVF;
***************
*** 633,639 ****
/* Immediate versions don't provide a code. */
if (!(opcode & OPCODE))
! tcode = ((opcode >> 6) & ((1 << 20) - 1));
/*
* (A short test says that IRIX 5.3 sends SIGTRAP for all trap
--- 639,645 ----
/* Immediate versions don't provide a code. */
if (!(opcode & OPCODE))
! tcode = ((opcode >> 6) & ((1 << 10) - 1));
/*
* (A short test says that IRIX 5.3 sends SIGTRAP for all trap
