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authorChuck Ebbert <76306.1226@compuserve.com>2005-09-12 18:49:25 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-12 10:50:58 -0700
commitff347b221512a83e7b08356729e3e2c14346e29e (patch)
tree3af9934eecd9ce119a840f53912e657951da9656
parent847815760cc0f41985b3185d780aa4369fcb475d (diff)
downloadlinux-linaro-ff347b221512a83e7b08356729e3e2c14346e29e.tar.gz
[PATCH] x86-64: Fix incorrect FP signals
This is the same patch that went into i386 just before 2.6.13 came out. I still can't build 64-bit user apps, so I tested with program (see below) in 32-bit mode on 64-bit kernel: Before: $ fpsig handler: nr = 8, si = 0x0804bc90, vuc = 0x0804bd10 handler: altstack is at 0x0804b000, ebp = 0x0804bc7c handler: si_signo = 8, si_errno = 0, si_code = 0 [unknown] handler: fpu cwd = 0xb40, fpu swd = 0xbaa0 handler: i387 unmasked precision exception, rounded up After: $ fpsig handler: nr = 8, si = 0x0804bc90, vuc = 0x0804bd10 handler: altstack is at 0x0804b000, ebp = 0x0804bc7c handler: si_signo = 8, si_errno = 0, si_code = 6 [inexact result] handler: fpu cwd = 0xb40, fpu swd = 0xbaa0 handler: i387 unmasked precision exception, rounded up Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/x86_64/kernel/traps.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 64a59cb4941..77658f7f4e8 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -795,13 +795,16 @@ asmlinkage void do_coprocessor_error(struct pt_regs *regs)
*/
cwd = get_fpu_cwd(task);
swd = get_fpu_swd(task);
- switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
+ switch (swd & ~cwd & 0x3f) {
case 0x000:
default:
break;
case 0x001: /* Invalid Op */
- case 0x041: /* Stack Fault */
- case 0x241: /* Stack Fault | Direction */
+ /*
+ * swd & 0x240 == 0x040: Stack Underflow
+ * swd & 0x240 == 0x240: Stack Overflow
+ * User must clear the SF bit (0x40) if set
+ */
info.si_code = FPE_FLTINV;
break;
case 0x002: /* Denormalize */