318c8114d
Denys Vlasenko
2017-10-05
Subject
free: make it NOFORK
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
NOFORK_NOEXEC.lst+1 -1
| @@ -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 | |
procps/free.c+23 -28
| @@ -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| //config: The shared memory column should be ignored; it is obsolete.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; | |