Mercurial > illumos > illumos-gate
changeset 13356:ae254853587f
789 dtrace may drop instructions when rapidly signalled
Reviewed by: Robert Mustacchi <robert.mustacchi@joyent.com>
Reviewed by: David Pacheco <dap@joyent.com>
Approved by: Garrett D'Amore <garrett@nexenta.com>
| author | Bryan Cantrill <bryan@joyent.com> |
|---|---|
| date | Wed, 09 Mar 2011 23:33:10 -0800 |
| parents | 15b74a2a9a9d |
| children | af2b8df56c61 |
| files | usr/src/uts/i86pc/os/dtrace_subr.c |
| diffstat | 1 files changed, 12 insertions(+), 7 deletions(-) [+] |
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--- a/usr/src/uts/i86pc/os/dtrace_subr.c Tue Feb 08 01:46:16 2011 -0800 +++ b/usr/src/uts/i86pc/os/dtrace_subr.c Wed Mar 09 23:33:10 2011 -0800 @@ -24,6 +24,10 @@ * Use is subject to license terms. */ +/* + * Copyright (c) 2011, Joyent, Inc. All rights reserved. + */ + #include <sys/dtrace.h> #include <sys/fasttrap.h> #include <sys/x_call.h> @@ -332,14 +336,15 @@ } /* - * If we've executed the original instruction, but haven't performed - * the jmp back to t->t_dtrace_npc or the clean up of any registers - * used to emulate %rip-relative instructions in 64-bit mode, do that - * here and take the signal right away. We detect this condition by - * seeing if the program counter is the range [scrpc + isz, astpc). + * If we have executed the original instruction, but we have performed + * neither the jmp back to t->t_dtrace_npc nor the clean up of any + * registers used to emulate %rip-relative instructions in 64-bit mode, + * we'll save ourselves some effort by doing that here and taking the + * signal right away. We detect this condition by seeing if the program + * counter is the range [scrpc + isz, astpc). */ - if (t->t_dtrace_astpc - rp->r_pc < - t->t_dtrace_astpc - t->t_dtrace_scrpc - isz) { + if (rp->r_pc >= t->t_dtrace_scrpc + isz && + rp->r_pc < t->t_dtrace_astpc) { #ifdef __amd64 /* * If there is a scratch register and we're on the