From 183dedfb90292926cf80c9ddd4b89d5e896736ba Mon Sep 17 00:00:00 2001 From: jhb Date: Fri, 21 Jun 2013 19:30:32 +0000 Subject: [PATCH] MFC 251637: Borrow the algorithm from kvm_getprocs() to fix procstat(1) to handle the case where the process tables grows in between the calls to fetch the size and fetch the table. Note that this is not a true MFC as the libprocstat library doesn't exist in 8.x and the relevant code is in the procstat binary instead. git-svn-id: svn://svn.freebsd.org/base/stable/8@252066 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- usr.bin/procstat/procstat.c | 47 +++++++++++++++++++++++++------------ 1 file changed, 32 insertions(+), 15 deletions(-) diff --git a/usr.bin/procstat/procstat.c b/usr.bin/procstat/procstat.c index ee95ae290..b8f5c9734 100644 --- a/usr.bin/procstat/procstat.c +++ b/usr.bin/procstat/procstat.c @@ -107,7 +107,7 @@ main(int argc, char *argv[]) int ch, interval, name[4], tmp; unsigned int i; struct kinfo_proc *kipp; - size_t len; + size_t len, olen; long l; pid_t pid; char *dummy; @@ -204,13 +204,21 @@ main(int argc, char *argv[]) if (sysctl(name, 3, NULL, &len, NULL, 0) < 0) err(-1, "sysctl: kern.proc.all"); - kipp = malloc(len); - if (kipp == NULL) - err(-1, "malloc"); - - if (sysctl(name, 3, kipp, &len, NULL, 0) < 0) { - free(kipp); - err(-1, "sysctl: kern.proc.all"); + kipp = NULL; + for (;;) { + len += len / 10; + kipp = reallocf(kipp, len); + if (kipp == NULL) + err(-1, "malloc"); + + olen = len; + if (sysctl(name, 3, kipp, &len, NULL, 0) < 0) { + if (errno == ENOMEM && olen == len) + continue; + free(kipp); + err(-1, "sysctl: kern.proc.all"); + } + break; } if (len % sizeof(*kipp) != 0) err(-1, "kinfo_proc mismatch"); @@ -242,13 +250,22 @@ main(int argc, char *argv[]) if (sysctl(name, 4, NULL, &len, NULL, 0) < 0) err(-1, "sysctl: kern.proc.pid: %d", pid); - kipp = malloc(len); - if (kipp == NULL) - err(-1, "malloc"); - - if (sysctl(name, 4, kipp, &len, NULL, 0) < 0) { - free(kipp); - err(-1, "sysctl: kern.proc.pid: %d", pid); + kipp = NULL; + for (;;) { + len += len / 10; + kipp = reallocf(kipp, len); + if (kipp == NULL) + err(-1, "malloc"); + + olen = len; + if (sysctl(name, 4, kipp, &len, NULL, 0) < 0) { + if (errno == ENOMEM && olen == len) + continue; + free(kipp); + err(-1, "sysctl: kern.proc.pid: %d", + pid); + } + break; } if (len != sizeof(*kipp)) err(-1, "kinfo_proc mismatch"); -- 2.45.0