X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=5827f6c7a14dfa3afbebc0e0befd601d5f6ca277;hb=bcb161b0230f;hp=52867a177981bd6206c27ea92b4b65f192595f54;hpb=c84a94883161073239c35d181e25823ff0454f68;p=elogind.git

diff --git a/src/shared/util.c b/src/shared/util.c
index 52867a177..5827f6c7a 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -80,6 +80,16 @@ char **saved_argv = NULL;
 static volatile unsigned cached_columns = 0;
 static volatile unsigned cached_lines = 0;
 
+#define PROCFS_PATH_LEN (sizeof("/proc/")-1 + DECIMAL_STR_MAX(pid_t))
+
+#define FORMAT_PROCFS_PATH(buffer, path, pid)                                                           \
+        do {                                                                                            \
+                assert_cc(sizeof(buffer) == (PROCFS_PATH_LEN + 1 + sizeof(path)));                      \
+                snprintf(buffer, sizeof(buffer) - 1, "/proc/%lu/%s", (unsigned long) pid, path);        \
+                char_array_0(buffer);                                                                   \
+        } while(0)
+
+
 size_t page_size(void) {
         static __thread size_t pgsz = 0;
         long r;
@@ -224,6 +234,17 @@ void close_many(const int fds[], unsigned n_fd) {
                 close_nointr_nofail(fds[i]);
 }
 
+int unlink_noerrno(const char *path) {
+        PROTECT_ERRNO;
+        int r;
+
+        r = unlink(path);
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
 int parse_boolean(const char *v) {
         assert(v);
 
@@ -571,12 +592,9 @@ int get_process_comm(pid_t pid, char **name) {
         if (pid == 0)
                 r = read_one_line_file("/proc/self/comm", name);
         else {
-                char *p;
-                if (asprintf(&p, "/proc/%lu/comm", (unsigned long) pid) < 0)
-                        return -ENOMEM;
-
-                r = read_one_line_file(p, name);
-                free(p);
+                char path[PROCFS_PATH_LEN + sizeof("/comm")];
+                FORMAT_PROCFS_PATH(path, "comm", pid);
+                r = read_one_line_file(path, name);
         }
 
         return r;
@@ -592,12 +610,9 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char *
         if (pid == 0)
                 f = fopen("/proc/self/cmdline", "re");
         else {
-                char *p;
-                if (asprintf(&p, "/proc/%lu/cmdline", (unsigned long) pid) < 0)
-                        return -ENOMEM;
-
-                f = fopen(p, "re");
-                free(p);
+                char path[PROCFS_PATH_LEN + sizeof("/cmdline")];
+                FORMAT_PROCFS_PATH(path, "cmdline", pid);
+                f = fopen(path, "re");
         }
 
         if (!f)
@@ -684,7 +699,7 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char *
 }
 
 int is_kernel_thread(pid_t pid) {
-        char *p;
+        char path[PROCFS_PATH_LEN + sizeof("/cmdline")];
         size_t count;
         char c;
         bool eof;
@@ -693,11 +708,8 @@ int is_kernel_thread(pid_t pid) {
         if (pid == 0)
                 return 0;
 
-        if (asprintf(&p, "/proc/%lu/cmdline", (unsigned long) pid) < 0)
-                return -ENOMEM;
-
-        f = fopen(p, "re");
-        free(p);
+        FORMAT_PROCFS_PATH(path, "cmdline", pid);
+        f = fopen(path, "re");
 
         if (!f)
                 return -errno;
@@ -722,12 +734,9 @@ int get_process_exe(pid_t pid, char **name) {
         if (pid == 0)
                 r = readlink_malloc("/proc/self/exe", name);
         else {
-                char *p;
-                if (asprintf(&p, "/proc/%lu/exe", (unsigned long) pid) < 0)
-                        return -ENOMEM;
-
-                r = readlink_malloc(p, name);
-                free(p);
+                char path[PROCFS_PATH_LEN + sizeof("/exe")];
+                FORMAT_PROCFS_PATH(path, "exe", pid);
+                r = readlink_malloc(path, name);
         }
 
         return r;
@@ -735,7 +744,7 @@ int get_process_exe(pid_t pid, char **name) {
 
 static int get_process_id(pid_t pid, const char *field, uid_t *uid) {
         _cleanup_fclose_ FILE *f = NULL;
-        _cleanup_free_ char *p = NULL;
+        char path[PROCFS_PATH_LEN + sizeof("/status")];
         char line[LINE_MAX];
 
         assert(field);
@@ -744,10 +753,8 @@ static int get_process_id(pid_t pid, const char *field, uid_t *uid) {
         if (pid == 0)
                 return getuid();
 
-        if (asprintf(&p, "/proc/%lu/status", (unsigned long) pid) < 0)
-                return -ENOMEM;
-
-        f = fopen(p, "re");
+        FORMAT_PROCFS_PATH(path, "status", pid);
+        f = fopen(path, "re");
         if (!f)
                 return -errno;
 
@@ -5252,7 +5259,7 @@ int get_home_dir(char **_h) {
         errno = 0;
         p = getpwuid(u);
         if (!p)
-                return errno ? -errno : -ESRCH;
+                return errno > 0 ? -errno : -ESRCH;
 
         if (!path_is_absolute(p->pw_dir))
                 return -EINVAL;