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| author | jkoshy <jkoshy@FreeBSD.org> | 2008-12-13 13:07:12 +0000 |
|---|---|---|
| committer | jkoshy <jkoshy@FreeBSD.org> | 2008-12-13 13:07:12 +0000 |
| commit | 57939c399f73afce189b6e3f815acf369c90e8f2 (patch) | |
| tree | 83dc6754204d60ec20d93f42fd864d37290d194f /sys/i386 | |
| parent | eea87ca93f64298bf448aef14d2833d79246936e (diff) | |
| download | FreeBSD-src-57939c399f73afce189b6e3f815acf369c90e8f2.zip FreeBSD-src-57939c399f73afce189b6e3f815acf369c90e8f2.tar.gz | |
- Bug fix: prevent a thread from migrating between CPUs between the
time it is marked for user space callchain capture in the NMI
handler and the time the callchain capture callback runs.
- Improve code and control flow clarity by invoking hwpmc(4)'s user
space callchain capture callback directly from low-level code.
Reviewed by: jhb (kern/subr_trap.c)
Testing (various patch revisions): gnn,
Fabien Thomas <fabien dot thomas at netasq dot com>,
Artem Belevich <artemb at gmail dot com>
Diffstat (limited to 'sys/i386')
| -rw-r--r-- | sys/i386/i386/exception.s | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/sys/i386/i386/exception.s b/sys/i386/i386/exception.s index 0ad2597..1451fa8 100644 --- a/sys/i386/i386/exception.s +++ b/sys/i386/i386/exception.s @@ -438,9 +438,18 @@ doreti_nmi: iret outofnmi: /* - * Clear interrupts and jump to AST handling code. + * Call the callchain capture hook after turning interrupts back on. */ + movl pmc_hook,%ecx + orl %ecx,%ecx + jz doreti_exit + pushl %esp /* frame pointer */ + pushl $PMC_FN_USER_CALLCHAIN /* command */ + movl PCPU(CURTHREAD),%eax + pushl %eax /* curthread */ sti + call *%ecx + addl $12,%esp jmp doreti_ast ENTRY(end_exceptions) #endif |
