diff options
| author | markj <markj@FreeBSD.org> | 2017-03-10 18:51:47 +0000 |
|---|---|---|
| committer | markj <markj@FreeBSD.org> | 2017-03-10 18:51:47 +0000 |
| commit | 69b7cc1189f913a712f9fa2f1a908e5d6f2de39a (patch) | |
| tree | aadc869a1073c2978c431abaa5feedb88977c203 /sys/cddl | |
| parent | 8336d2307be89f71848e84072fdcd4bb703b1a9b (diff) | |
| download | FreeBSD-src-69b7cc1189f913a712f9fa2f1a908e5d6f2de39a.zip FreeBSD-src-69b7cc1189f913a712f9fa2f1a908e5d6f2de39a.tar.gz | |
MFC r313841, r313850:
Prevent CPU migration when checking the DTrace nofault flag on x86.
Diffstat (limited to 'sys/cddl')
| -rw-r--r-- | sys/cddl/dev/dtrace/amd64/dtrace_subr.c | 11 | ||||
| -rw-r--r-- | sys/cddl/dev/dtrace/i386/dtrace_subr.c | 11 |
2 files changed, 20 insertions, 2 deletions
diff --git a/sys/cddl/dev/dtrace/amd64/dtrace_subr.c b/sys/cddl/dev/dtrace/amd64/dtrace_subr.c index df39d2e..717f455 100644 --- a/sys/cddl/dev/dtrace/amd64/dtrace_subr.c +++ b/sys/cddl/dev/dtrace/amd64/dtrace_subr.c @@ -41,7 +41,9 @@ #include <sys/dtrace_impl.h> #include <sys/dtrace_bsd.h> #include <machine/clock.h> +#include <machine/cpufunc.h> #include <machine/frame.h> +#include <machine/psl.h> #include <vm/pmap.h> extern void dtrace_getnanotime(struct timespec *tsp); @@ -384,6 +386,8 @@ dtrace_gethrestime(void) int dtrace_trap(struct trapframe *frame, u_int type) { + uint16_t nofault; + /* * A trap can occur while DTrace executes a probe. Before * executing the probe, DTrace blocks re-scheduling and sets @@ -393,7 +397,12 @@ dtrace_trap(struct trapframe *frame, u_int type) * * Check if DTrace has enabled 'no-fault' mode: */ - if ((cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT) != 0) { + sched_pin(); + nofault = cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT; + sched_unpin(); + if (nofault) { + KASSERT((read_rflags() & PSL_I) == 0, ("interrupts enabled")); + /* * There are only a couple of trap types that are expected. * All the rest will be handled in the usual way. diff --git a/sys/cddl/dev/dtrace/i386/dtrace_subr.c b/sys/cddl/dev/dtrace/i386/dtrace_subr.c index b70eab9..3801c1b 100644 --- a/sys/cddl/dev/dtrace/i386/dtrace_subr.c +++ b/sys/cddl/dev/dtrace/i386/dtrace_subr.c @@ -42,7 +42,9 @@ #include <sys/dtrace_impl.h> #include <sys/dtrace_bsd.h> #include <machine/clock.h> +#include <machine/cpufunc.h> #include <machine/frame.h> +#include <machine/psl.h> #include <vm/pmap.h> extern uintptr_t kernelbase; @@ -386,6 +388,8 @@ dtrace_gethrestime(void) int dtrace_trap(struct trapframe *frame, u_int type) { + uint16_t nofault; + /* * A trap can occur while DTrace executes a probe. Before * executing the probe, DTrace blocks re-scheduling and sets @@ -395,7 +399,12 @@ dtrace_trap(struct trapframe *frame, u_int type) * * Check if DTrace has enabled 'no-fault' mode: */ - if ((cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT) != 0) { + sched_pin(); + nofault = cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT; + sched_unpin(); + if (nofault) { + KASSERT((read_eflags() & PSL_I) == 0, ("interrupts enabled")); + /* * There are only a couple of trap types that are expected. * All the rest will be handled in the usual way. |
