From 901108257e3b1da07033f4e6e053b5be42b1c8b0 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 23 Jul 2015 23:36:34 +0200 Subject: fileio: get_status_field() don't clobber arg on OOM According to our coding style guidelines we shouldn't clobber pass-by-ref arguments on failure, hence don't do so here either. --- src/basic/fileio.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'src/basic') diff --git a/src/basic/fileio.c b/src/basic/fileio.c index d592bf5ac9..2216853777 100644 --- a/src/basic/fileio.c +++ b/src/basic/fileio.c @@ -786,7 +786,7 @@ int executable_is_script(const char *path, char **interpreter) { */ int get_status_field(const char *filename, const char *pattern, char **field) { _cleanup_free_ char *status = NULL; - char *t; + char *t, *f; size_t len; int r; @@ -820,9 +820,10 @@ int get_status_field(const char *filename, const char *pattern, char **field) { len = strcspn(t, WHITESPACE); - *field = strndup(t, len); - if (!*field) + f = strndup(t, len); + if (!f) return -ENOMEM; + *field = f; return 0; } -- cgit v1.2.3-54-g00ecf From a644184a177caa709e1bb784e4f169101194b610 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 23 Jul 2015 23:44:40 +0200 Subject: process: return ESRCH when a PID is not valid anymore so far, when we read something from /proc/$PID we would pass on the ENOENT from the kernel as error, if the process was missing. With this change we systematically convert this to ESRCH, which is the more appropriate error code, and what all the other glibc/syscalls like kill() use. All code that calls these functions should be fine with this change. In fact, one invocation of get_process_exe() in bus-creds.c already assumed ESRCH would be returned if a process is missing, and this assumption is now validated after the change. --- src/basic/process-util.c | 43 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 35 insertions(+), 8 deletions(-) (limited to 'src/basic') diff --git a/src/basic/process-util.c b/src/basic/process-util.c index 2c05f2fee4..66395b7de9 100644 --- a/src/basic/process-util.c +++ b/src/basic/process-util.c @@ -43,7 +43,10 @@ int get_process_state(pid_t pid) { assert(pid >= 0); p = procfs_file_alloca(pid, "stat"); + r = read_one_line_file(p, &line); + if (r == -ENOENT) + return -ESRCH; if (r < 0) return r; @@ -87,8 +90,11 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * p = procfs_file_alloca(pid, "cmdline"); f = fopen(p, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } if (max_length == 0) { size_t len = 0, allocated = 0; @@ -182,8 +188,11 @@ int is_kernel_thread(pid_t pid) { p = procfs_file_alloca(pid, "cmdline"); f = fopen(p, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } count = fread(&c, 1, 1, f); eof = feof(f); @@ -199,13 +208,18 @@ int is_kernel_thread(pid_t pid) { int get_process_capeff(pid_t pid, char **capeff) { const char *p; + int r; assert(capeff); assert(pid >= 0); p = procfs_file_alloca(pid, "status"); - return get_status_field(p, "\nCapEff:", capeff); + r = get_status_field(p, "\nCapEff:", capeff); + if (r == -ENOENT) + return -ESRCH; + + return r; } static int get_process_link_contents(const char *proc_file, char **name) { @@ -215,8 +229,10 @@ static int get_process_link_contents(const char *proc_file, char **name) { assert(name); r = readlink_malloc(proc_file, name); + if (r == -ENOENT) + return -ESRCH; if (r < 0) - return r == -ENOENT ? -ESRCH : r; + return r; return 0; } @@ -253,8 +269,11 @@ static int get_process_id(pid_t pid, const char *field, uid_t *uid) { p = procfs_file_alloca(pid, "status"); f = fopen(p, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } FOREACH_LINE(line, f, return -errno) { char *l; @@ -316,8 +335,11 @@ int get_process_environ(pid_t pid, char **env) { p = procfs_file_alloca(pid, "environ"); f = fopen(p, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } while ((c = fgetc(f)) != EOF) { if (!GREEDY_REALLOC(outcome, allocated, sz + 5)) @@ -355,6 +377,8 @@ int get_parent_of_pid(pid_t pid, pid_t *_ppid) { p = procfs_file_alloca(pid, "stat"); r = read_one_line_file(p, &line); + if (r == -ENOENT) + return -ESRCH; if (r < 0) return r; @@ -475,8 +499,11 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value) { path = procfs_file_alloca(pid, "environ"); f = fopen(path, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } l = strlen(field); r = 0; @@ -535,7 +562,7 @@ bool pid_is_alive(pid_t pid) { return false; r = get_process_state(pid); - if (r == -ENOENT || r == 'Z') + if (r == -ESRCH || r == 'Z') return false; return true; -- cgit v1.2.3-54-g00ecf From 03c55bc0b980e2a6aaf6f166a9271ed8ecce2222 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 23 Jul 2015 23:47:54 +0200 Subject: process: an empty environment block should be returned as such An empty env block is completely valid, hence return it as such, and don't turn it into an error. --- src/basic/process-util.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'src/basic') diff --git a/src/basic/process-util.c b/src/basic/process-util.c index 66395b7de9..61f188467f 100644 --- a/src/basic/process-util.c +++ b/src/basic/process-util.c @@ -351,10 +351,13 @@ int get_process_environ(pid_t pid, char **env) { sz += cescape_char(c, outcome + sz); } - if (sz == 0) - return -ENOENT; + if (!outcome) { + outcome = strdup(""); + if (!outcome) + return -ENOMEM; + } else + outcome[sz] = '\0'; - outcome[sz] = '\0'; *env = outcome; outcome = NULL; -- cgit v1.2.3-54-g00ecf