free: make it NOFORK

function                                             old     new   delta
parse_cached_kb                                        -      85     +85
free_main                                            580     537     -43
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 85/-43)             Total: 42 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/NOFORK_NOEXEC.lst b/NOFORK_NOEXEC.lst
index 4e53d7204a7551299752844f3f4faeb0d6d0bd00..72c33ddd76e1871b186354c80911caf1d753cbb8 100644 (file)
--- a/NOFORK_NOEXEC.lst
+++ b/NOFORK_NOEXEC.lst
@@ -144,7 +144,7 @@ flash_unlock - hardware
 flashcp - hardware
 flock - spawner, changes state (file locks), let's play safe and not be noexec
 fold - noexec. runner
-free - noexec. nofork candidate(struct globals, needs to close /proc/meminfo fd)
+free - NOFORK
 freeramdisk - noexec. leaks: open+ioctl_or_perror_and_die
 fsck - interactive, longterm
 fsck.minix - needs ^C

diff --git a/procps/free.c b/procps/free.c
index b57e4a322054c9597dce2c21a6684bc96246cc89..fa423cfa5b178c7105e6c0a3c4daf8d89547e09e 100644 (file)
--- a/procps/free.c
+++ b/procps/free.c
@@ -15,7 +15,7 @@
 //config:      memory in the system, as well as the buffers used by the kernel.
 //config:      The shared memory column should be ignored; it is obsolete.
 
-//applet:IF_FREE(APPLET_NOEXEC(free, free, BB_DIR_USR_BIN, BB_SUID_DROP, free))
+//applet:IF_FREE(APPLET_NOFORK(free, free, BB_DIR_USR_BIN, BB_SUID_DROP, free))
 
 //kbuild:lib-$(CONFIG_FREE) += free.o
 
@@ -40,25 +40,21 @@
 struct globals {
        unsigned mem_unit;
 #if ENABLE_DESKTOP
-       unsigned unit_steps;
-# define G_unit_steps G.unit_steps
+       uint8_t unit_steps;
+# define G_unit_steps g->unit_steps
 #else
 # define G_unit_steps 10
 #endif
-} FIX_ALIASING;
-#define G (*(struct globals*)bb_common_bufsiz1)
-#define INIT_G() do { \
-       setup_common_bufsiz(); \
-       /* NB: noexec applet - globals not zeroed */ \
-} while (0)
+};
+/* Because of NOFORK, "globals" are not in global data */
 
-
-static unsigned long long scale(unsigned long d)
+static unsigned long long scale(struct globals *g, unsigned long d)
 {
-       return ((unsigned long long)d * G.mem_unit) >> G_unit_steps;
+       return ((unsigned long long)d * g->mem_unit) >> G_unit_steps;
 }
 
-static unsigned long parse_cached_kb(void)
+/* NOINLINE reduces main() stack usage, which makes code smaller (on x86 at least) */
+static NOINLINE unsigned long parse_cached_kb(void)
 {
        char buf[60]; /* actual lines we expect are ~30 chars or less */
        FILE *fp;
@@ -69,8 +65,8 @@ static unsigned long parse_cached_kb(void)
                if (sscanf(buf, "Cached: %lu %*s\n", &cached) == 1)
                        break;
        }
-       if (ENABLE_FEATURE_CLEAN_UP)
-               fclose(fp);
+       /* Have to close because of NOFORK */
+       fclose(fp);
 
        return cached;
 }
@@ -78,11 +74,10 @@ static unsigned long parse_cached_kb(void)
 int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
 {
+       struct globals G;
        struct sysinfo info;
        unsigned long long cached;
 
-       INIT_G();
-
 #if ENABLE_DESKTOP
        G.unit_steps = 10;
        if (argv[1] && argv[1][0] == '-') {
@@ -123,12 +118,12 @@ int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
 #define FIELDS_2 (FIELDS_6 + 4*6)
 
        printf(FIELDS_6,
-               scale(info.totalram),                //total
-               scale(info.totalram - info.freeram), //used
-               scale(info.freeram),                 //free
-               scale(info.sharedram),               //shared
-               scale(info.bufferram),               //buffers
-               scale(cached)                        //cached
+               scale(&G, info.totalram),                //total
+               scale(&G, info.totalram - info.freeram), //used
+               scale(&G, info.freeram),                 //free
+               scale(&G, info.sharedram),               //shared
+               scale(&G, info.bufferram),               //buffers
+               scale(&G, cached)                        //cached
        );
        /* Show alternate, more meaningful busy/free numbers by counting
         * buffer cache as free memory. */
@@ -136,15 +131,15 @@ int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
        cached += info.freeram;
        cached += info.bufferram;
        printf(FIELDS_2,
-               scale(info.totalram - cached), //used
-               scale(cached)                  //free
+               scale(&G, info.totalram - cached), //used
+               scale(&G, cached)                  //free
        );
 #if BB_MMU
        printf("Swap:  ");
        printf(FIELDS_3,
-               scale(info.totalswap),                 //total
-               scale(info.totalswap - info.freeswap), //used
-               scale(info.freeswap)                   //free
+               scale(&G, info.totalswap),                 //total
+               scale(&G, info.totalswap - info.freeswap), //used
+               scale(&G, info.freeswap)                   //free
        );
 #endif
        return EXIT_SUCCESS;