diff options
| author | Niels Provos <provos@cvs.openbsd.org> | 2002-08-02 02:26:28 +0000 |
|---|---|---|
| committer | Niels Provos <provos@cvs.openbsd.org> | 2002-08-02 02:26:28 +0000 |
| commit | ad299a67a4d5c3ad2ad69163233b6c5190d5ef19 (patch) | |
| tree | d02f82a46c038dfe8a4160c4220b0e24135f539a /bin/systrace | |
| parent | 638c22010bfbb8321b9df281db1f6cc474560412 (diff) | |
performance improvement, reduces number of ioctl calls
Diffstat (limited to 'bin/systrace')
| -rw-r--r-- | bin/systrace/intercept.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/bin/systrace/intercept.c b/bin/systrace/intercept.c index 6208d87be70..496505c2640 100644 --- a/bin/systrace/intercept.c +++ b/bin/systrace/intercept.c @@ -1,4 +1,4 @@ -/* $OpenBSD: intercept.c,v 1.22 2002/08/01 20:50:17 provos Exp $ */ +/* $OpenBSD: intercept.c,v 1.23 2002/08/02 02:26:27 provos Exp $ */ /* * Copyright 2002 Niels Provos <provos@citi.umich.edu> * All rights reserved. @@ -487,21 +487,28 @@ char * intercept_get_string(int fd, pid_t pid, void *addr) { static char name[_POSIX2_LINE_MAX]; - int off = 0, done = 0; + int off = 0, done = 0, stride; + stride = 32; do { if (intercept.io(fd, pid, INTERCEPT_READ, (char *)addr + off, - &name[off], 4) == -1) { - warn("%s: ioctl", __func__); - return (NULL); + &name[off], stride) == -1) { + if (errno != EINVAL || stride == 4) { + warn("%s: ioctl", __func__); + return (NULL); + } + + /* Try smaller stride */ + stride /= 2; + continue; } - off += 4; + off += stride; name[off] = '\0'; if (strlen(name) < off) done = 1; - } while (!done && off + 5 < sizeof(name)); + } while (!done && off + stride + 1 < sizeof(name)); if (!done) { warnx("%s: string too long", __func__); |