From d840c5d139cfa50fbe4f6f67c178b0edf0c690c8 Mon Sep 17 00:00:00 2001 From: Ron Yorston Date: Sun, 19 Jul 2015 23:05:20 +0200 Subject: [PATCH] libbb: add a function to make a copy of a region of memory Introduce a library routine to package the idiom: p = xmalloc(b, n); memcpy(p, b, n); and use it where possible. The example in traceroute used xzalloc but it didn't need to. function old new delta xmemdup - 32 +32 last_main 834 826 -8 make_device 2321 2311 -10 common_traceroute_main 3698 3685 -13 readtoken1 3182 3168 -14 procps_scan 1222 1206 -16 forkchild 655 638 -17 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/6 up/down: 32/-78) Total: -46 bytes Signed-off-by: Ron Yorston Signed-off-by: Denys Vlasenko --- include/libbb.h | 1 + libbb/procps.c | 3 +-- libbb/xfuncs_printf.c | 5 +++++ miscutils/last_fancy.c | 4 ++-- networking/traceroute.c | 11 +---------- networking/udhcp/d6_dhcpc.c | 2 +- shell/ash.c | 2 +- util-linux/mdev.c | 2 +- 8 files changed, 13 insertions(+), 17 deletions(-) diff --git a/include/libbb.h b/include/libbb.h index f0ac1f50d..54d01b75a 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -673,6 +673,7 @@ uint16_t inet_cksum(uint16_t *addr, int len) FAST_FUNC; char *xstrdup(const char *s) FAST_FUNC RETURNS_MALLOC; char *xstrndup(const char *s, int n) FAST_FUNC RETURNS_MALLOC; +void *xmemdup(const void *s, int n) FAST_FUNC RETURNS_MALLOC; void overlapping_strcpy(char *dst, const char *src) FAST_FUNC; char *safe_strncpy(char *dst, const char *src, size_t size) FAST_FUNC; char *strncpy_IFNAMSIZ(char *dst, const char *src) FAST_FUNC; diff --git a/libbb/procps.c b/libbb/procps.c index 3d335b37b..71ad071e6 100644 --- a/libbb/procps.c +++ b/libbb/procps.c @@ -554,8 +554,7 @@ procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags) break; if (flags & PSSCAN_ARGVN) { sp->argv_len = n; - sp->argv0 = xmalloc(n + 1); - memcpy(sp->argv0, buf, n + 1); + sp->argv0 = xmemdup(buf, n + 1); /* sp->argv0[n] = '\0'; - buf has it */ } else { sp->argv_len = 0; diff --git a/libbb/xfuncs_printf.c b/libbb/xfuncs_printf.c index e4ac6a002..73488908d 100644 --- a/libbb/xfuncs_printf.c +++ b/libbb/xfuncs_printf.c @@ -112,6 +112,11 @@ char* FAST_FUNC xstrndup(const char *s, int n) return memcpy(t, s, n); } +void* FAST_FUNC xmemdup(const void *s, int n) +{ + return memcpy(xmalloc(n), s, n); +} + // Die if we can't open a file and return a FILE* to it. // Notice we haven't got xfread(), This is for use with fscanf() and friends. FILE* FAST_FUNC xfopen(const char *path, const char *mode) diff --git a/miscutils/last_fancy.c b/miscutils/last_fancy.c index 8194e31b5..e56e0ba85 100644 --- a/miscutils/last_fancy.c +++ b/miscutils/last_fancy.c @@ -233,7 +233,7 @@ int last_main(int argc UNUSED_PARAM, char **argv) break; } /* add_entry */ - llist_add_to(&zlist, memcpy(xmalloc(sizeof(ut)), &ut, sizeof(ut))); + llist_add_to(&zlist, xmemdup(&ut, sizeof(ut))); break; case USER_PROCESS: { int show; @@ -275,7 +275,7 @@ int last_main(int argc UNUSED_PARAM, char **argv) show_entry(&ut, state, boot_time); } /* add_entry */ - llist_add_to(&zlist, memcpy(xmalloc(sizeof(ut)), &ut, sizeof(ut))); + llist_add_to(&zlist, xmemdup(&ut, sizeof(ut))); break; } } diff --git a/networking/traceroute.c b/networking/traceroute.c index 97a7a19e0..12ba614e8 100644 --- a/networking/traceroute.c +++ b/networking/traceroute.c @@ -387,15 +387,6 @@ struct globals { #define outudp ((struct udphdr *)(outip + 1)) -/* libbb candidate? tftp uses this idiom too */ -static len_and_sockaddr* dup_sockaddr(const len_and_sockaddr *lsa) -{ - len_and_sockaddr *new_lsa = xzalloc(LSA_LEN_SIZE + lsa->len); - memcpy(new_lsa, lsa, LSA_LEN_SIZE + lsa->len); - return new_lsa; -} - - static int wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms) { @@ -1074,7 +1065,7 @@ common_traceroute_main(int op, char **argv) printf(" from %s", source); printf(", %d hops max, %d byte packets\n", max_ttl, packlen); - from_lsa = dup_sockaddr(dest_lsa); + from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len); lastaddr = xzalloc(dest_lsa->len); to = xzalloc(dest_lsa->len); seq = 0; diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c index 044f04673..4e9b705b9 100644 --- a/networking/udhcp/d6_dhcpc.c +++ b/networking/udhcp/d6_dhcpc.c @@ -118,7 +118,7 @@ static void *d6_copy_option(uint8_t *option, uint8_t *option_end, unsigned code) uint8_t *opt = d6_find_option(option, option_end, code); if (!opt) return opt; - return memcpy(xmalloc(opt[3] + 4), opt, opt[3] + 4); + return xmemdup(opt, opt[3] + 4); } static void *d6_store_blob(void *dst, const void *src, unsigned len) diff --git a/shell/ash.c b/shell/ash.c index f4779ee2b..f6190c3e2 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -4751,7 +4751,7 @@ forkchild(struct job *jp, union node *n, int mode) * Our solution: ONLY bare $(trap) or `trap` is special. */ /* Save trap handler strings for trap builtin to print */ - trap_ptr = memcpy(xmalloc(sizeof(trap)), trap, sizeof(trap)); + trap_ptr = xmemdup(trap, sizeof(trap)); /* Fall through into clearing traps */ } clear_traps(); diff --git a/util-linux/mdev.c b/util-linux/mdev.c index ca4b91510..662e8ab38 100644 --- a/util-linux/mdev.c +++ b/util-linux/mdev.c @@ -471,7 +471,7 @@ static const struct rule *next_rule(void) if (G.parser) { parse_next_rule(); if (G.rule_vec) { /* mdev -s */ - rule = memcpy(xmalloc(sizeof(G.cur_rule)), &G.cur_rule, sizeof(G.cur_rule)); + rule = xmemdup(&G.cur_rule, sizeof(G.cur_rule)); G.rule_vec = xrealloc_vector(G.rule_vec, 4, G.rule_idx); G.rule_vec[G.rule_idx++] = rule; dbg3("> G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]); -- 2.25.1