diff options
| author | Andriy Gapon <avg@FreeBSD.org> | 2024-04-21 10:07:36 +0000 |
|---|---|---|
| committer | Andriy Gapon <avg@FreeBSD.org> | 2024-04-21 12:28:59 +0000 |
| commit | f12a50fed2df3994b05d7c8702f06bb117c156d6 (patch) | |
| tree | 1cf2f356cf32a1a68ed668000f307edf19c76d42 | |
| parent | c61eb1679d6a256db0436c97884e07d14c6d1213 (diff) | |
Revert "dtrace: make 'ring' and 'fill' policies imply 'noswitch' flag"
This reverts commit e92491d95ff3500e140eafa614e88ca84ffb0d26.
It was cherry-picked as f0ed49921c2891733b7ee65679a8dcba5398e3b6.
The general idea looked good to me. In particular, it allowed to save
some memory and avoid memory allocation failures when a large buffer
size was requested along with ring and fill policies.
But I didn't take into account that the second, supposedly unused
buffer, was actually used as the scratch buffer. The scratch buffer is
used as a temporary space for DTrace subroutines like copyin, copyinstr,
and alloca.
I think that the change can be fixed by allocating a separate smaller
buffer for the scratch buffer, but that fix would require more work than
I am able to do now. Hence the revert.
Reported by: Domagoj Stolfa
Diagnosed by: Domagoj Stolfa, markj
(cherry picked from commit b9827c007a7a39c7aeef73f8efc217b7b0099464)
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c index 17d9536b2428..6ae0322ebb0f 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c +++ b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c @@ -12055,6 +12055,7 @@ dtrace_buffer_switch(dtrace_buffer_t *buf) hrtime_t now; ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH)); + ASSERT(!(buf->dtb_flags & DTRACEBUF_RING)); cookie = dtrace_interrupt_disable(); now = dtrace_gethrtime(); @@ -14862,10 +14863,10 @@ dtrace_state_buffer(dtrace_state_t *state, dtrace_buffer_t *buf, int which) if (which == DTRACEOPT_BUFSIZE) { if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_RING) - flags |= DTRACEBUF_RING | DTRACEBUF_NOSWITCH; + flags |= DTRACEBUF_RING; if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_FILL) - flags |= DTRACEBUF_FILL | DTRACEBUF_NOSWITCH; + flags |= DTRACEBUF_FILL; if (state != dtrace_anon.dta_state || state->dts_activity != DTRACE_ACTIVITY_ACTIVE) |