From: David Daney <ddaney@avtrex.com>
To: "Maciej W. Rozycki" <macro@ds2.pg.gda.pl>
Cc: cgd@broadcom.com, Ralf Baechle <ralf@linux-mips.org>,
linux-mips@linux-mips.org, binutils@sources.redhat.com
Subject: Re: [Patch] / 0 should send SIGFPE not SIGTRAP...
Date: Fri, 11 Jun 2004 20:52:00 -0000 [thread overview]
Message-ID: <40CA1B35.6010603@avtrex.com> (raw)
In-Reply-To: <Pine.LNX.4.55.0406112133380.13062@jurand.ds.pg.gda.pl>
[-- Attachment #1: Type: text/plain, Size: 364 bytes --]
Maciej W. Rozycki wrote:
>On Fri, 11 Jun 2004 cgd@broadcom.com wrote:
>
>
>>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.
>
>
>
How about the attached (lightly tested) patch?
David Daney.
[-- Attachment #2: traps.diff --]
[-- Type: text/plain, Size: 2111 bytes --]
*** ../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
next prev parent reply other threads:[~2004-06-11 20:52 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <40C9F5A4.2050606@avtrex.com>
[not found] ` <40C9F5FE.8030607@avtrex.com>
2004-06-11 18:22 ` David Daney
2004-06-11 19:12 ` Maciej W. Rozycki
[not found] ` <mailpost.1086981251.16853@news-sj1-1>
2004-06-11 19:28 ` cgd
2004-06-11 19:50 ` Maciej W. Rozycki
2004-06-11 20:52 ` David Daney [this message]
2004-06-11 21:12 ` [Patch] (revised patch) " David Daney
2004-06-13 8:33 ` Geert Uytterhoeven
2004-06-14 12:52 ` Maciej W. Rozycki
2004-06-22 21:30 ` [Patch] " Maciej W. Rozycki
2004-06-23 19:33 ` David Daney
2004-06-23 19:38 ` Maciej W. Rozycki
2004-06-24 10:39 ` Richard Sandiford
2004-06-24 18:34 ` Maciej W. Rozycki
[not found] ` <mailpost.1088102121.25381@news-sj1-1>
2004-06-24 18:47 ` cgd
2004-06-28 13:46 ` Maciej W. Rozycki
2004-06-28 15:19 cgd
2004-06-28 15:36 ` Maciej W. Rozycki
2004-07-19 14:22 ` Maciej W. Rozycki
[not found] ` <mailpost.1090246948.15046@news-sj1-1>
2004-07-19 15:19 ` cgd
2004-07-19 15:42 ` Maciej W. Rozycki
2004-07-19 23:29 ` Thiemo Seufer
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