From 25cfe4996ec967e19283f6b66c45cf220a615528 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sun, 20 Apr 2008 01:27:59 +0000 Subject: [PATCH] libbb: prevent xmalloc_open_read_close from dying on seek failure start_stop_daemon: use open_read_close instead of xmalloc_open_read_close start_stop_daemon: use local structure instead of global one function old new delta check 1620 1661 +41 xmalloc_open_read_close 171 190 +19 start_stop_daemon_main 976 954 -22 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/1 up/down: 60/-22) Total: 38 bytes --- debianutils/start_stop_daemon.c | 40 ++++++++++++++------------------- libbb/read.c | 23 +++++++++++++------ 2 files changed, 33 insertions(+), 30 deletions(-) diff --git a/debianutils/start_stop_daemon.c b/debianutils/start_stop_daemon.c index c5c4059a1..9150763cb 100644 --- a/debianutils/start_stop_daemon.c +++ b/debianutils/start_stop_daemon.c @@ -32,7 +32,6 @@ struct globals { int user_id; smallint quiet; smallint signal_nr; - struct stat execstat; }; #define G (*(struct globals*)&bb_common_bufsiz1) #define found (G.found ) @@ -43,7 +42,6 @@ struct globals { #define user_id (G.user_id ) #define quiet (G.quiet ) #define signal_nr (G.signal_nr ) -#define execstat (G.execstat ) #define INIT_G() \ do { \ user_id = -1; \ @@ -53,12 +51,13 @@ struct globals { static int pid_is_exec(pid_t pid) { - struct stat st; + struct stat st, execstat; char buf[sizeof("/proc//exe") + sizeof(int)*3]; sprintf(buf, "/proc/%u/exe", pid); if (stat(buf, &st) < 0) return 0; + xstat(execname, &execstat); if (st.st_dev == execstat.st_dev && st.st_ino == execstat.st_ino) return 1; @@ -78,24 +77,21 @@ static int pid_is_user(int pid) static int pid_is_cmd(pid_t pid) { - char fname[sizeof("/proc//stat") + sizeof(int)*3]; - char *buf; - int r = 0; - - sprintf(fname, "/proc/%u/stat", pid); - buf = xmalloc_open_read_close(fname, NULL); - if (buf) { - char *p = strchr(buf, '('); - if (p) { - char *pe = strrchr(++p, ')'); - if (pe) { - *pe = '\0'; - r = !strcmp(p, cmdname); - } - } - free(buf); - } - return r; + char buf[256]; /* is it big enough? */ + char *p, *pe; + + sprintf(buf, "/proc/%u/stat", pid); + if (open_read_close(buf, buf, sizeof(buf) - 1) < 0) + return 0; + buf[sizeof(buf) - 1] = '\0'; /* paranoia */ + p = strchr(buf, '('); + if (!p) + return 0; + pe = strrchr(++p, ')'); + if (!pe) + return 0; + *pe = '\0'; + return !strcmp(p, cmdname); } static void check(int pid) @@ -303,8 +299,6 @@ int start_stop_daemon_main(int argc ATTRIBUTE_UNUSED, char **argv) if (errno) user_id = xuname2uid(userspec); } - if (execname) - xstat(execname, &execstat); do_procinit(); /* Both start and stop needs to know current processes */ diff --git a/libbb/read.c b/libbb/read.c index ba366cb97..e5f140f3b 100644 --- a/libbb/read.c +++ b/libbb/read.c @@ -208,25 +208,34 @@ ssize_t open_read_close(const char *filename, void *buf, size_t size) void *xmalloc_open_read_close(const char *filename, size_t *sizep) { char *buf; - size_t size = sizep ? *sizep : INT_MAX; + size_t size; int fd; off_t len; fd = open(filename, O_RDONLY); if (fd < 0) return NULL; + /* /proc/N/stat files report len 0 here */ /* In order to make such files readable, we add small const */ - len = xlseek(fd, 0, SEEK_END) | 0x3ff; /* + up to 1k */ - xlseek(fd, 0, SEEK_SET); - if (len < size) - size = len; + size = 0x3ff; /* read only 1k on unseekable files */ + len = lseek(fd, 0, SEEK_END) | 0x3ff; /* + up to 1k */ + if (len != (off_t)-1) { + xlseek(fd, 0, SEEK_SET); + size = sizep ? *sizep : INT_MAX; + if (len < size) + size = len; + } + buf = xmalloc(size + 1); size = read_close(fd, buf, size); - if ((ssize_t)size < 0) - bb_perror_msg_and_die("'%s'", filename); + if ((ssize_t)size < 0) { + free(buf); + return NULL; + } xrealloc(buf, size + 1); buf[size] = '\0'; + if (sizep) *sizep = size; return buf; -- 2.25.1