busybox/include/busybox.h

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/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#ifndef BUSYBOX_H
#define BUSYBOX_H 1
#include "libbb.h"
/* BB_DIR_foo and BB_SUID_bar constants: */
#include "applet_metadata.h"
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PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
/* Defined in appletlib.c (by including generated applet_tables.h) */
/* Keep in sync with applets/applet_tables.c! */
extern const char applet_names[] ALIGN1;
extern int (*const applet_main[])(int argc, char **argv);
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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extern const uint8_t applet_flags[] ALIGN1;
extern const uint8_t applet_suid[] ALIGN1;
extern const uint8_t applet_install_loc[] ALIGN1;
#if ENABLE_FEATURE_PREFER_APPLETS
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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# define APPLET_IS_NOFORK(i) (applet_flags[(i)/4] & (1 << (2 * ((i)%4))))
# define APPLET_IS_NOEXEC(i) (applet_flags[(i)/4] & (1 << ((2 * ((i)%4))+1)))
#else
# define APPLET_IS_NOFORK(i) 0
# define APPLET_IS_NOEXEC(i) 0
#endif
#if ENABLE_FEATURE_SUID
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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# define APPLET_SUID(i) ((applet_suid[(i)/4] >> (2 * ((i)%4)) & 3))
#endif
#if ENABLE_FEATURE_INSTALLER
#define APPLET_INSTALL_LOC(i) ({ \
unsigned v = (i); \
if (v & 1) v = applet_install_loc[v/2] >> 4; \
else v = applet_install_loc[v/2] & 0xf; \
v; })
#endif
/* Length of these names has effect on size of libbusybox
* and "individual" binaries. Keep them short.
*/
#if ENABLE_BUILD_LIBBUSYBOX
#if ENABLE_FEATURE_SHARED_BUSYBOX
int lbb_main(char **argv) EXTERNALLY_VISIBLE;
#else
int lbb_main(char **argv);
#endif
#endif
POP_SAVED_FUNCTION_VISIBILITY
#endif