diff options
| -rw-r--r-- | libbb/Config.in | 10 | ||||
| -rw-r--r-- | libbb/copyfd.c | 32 |
2 files changed, 34 insertions, 8 deletions
diff --git a/libbb/Config.in b/libbb/Config.in index 5055015cf..6bbeffb43 100644 --- a/libbb/Config.in +++ b/libbb/Config.in @@ -110,6 +110,16 @@ config FEATURE_EDITING_FANCY_PROMPT Setting this option allows for prompts to use things like \w and \$ and escape codes. +config FEATURE_COPYBUF_KB + int "Copy buffer size, in kilobytes" + range 1 1024 + default 4 + help + Size of buffer used by cp, mv, install etc. + Buffers which are 4 kb or less will be allocated on stack. + Bigger buffers will be allocated with mmap, with fallback to 4 kb + stack buffer if mmap fails. + config MONOTONIC_SYSCALL bool "Use clock_gettime(CLOCK_MONOTONIC) syscall" default y diff --git a/libbb/copyfd.c b/libbb/copyfd.c index 3255e424a..ed383ae28 100644 --- a/libbb/copyfd.c +++ b/libbb/copyfd.c @@ -9,31 +9,42 @@ #include "libbb.h" -#if BUFSIZ < 4096 -#undef BUFSIZ -#define BUFSIZ 4096 -#endif - /* Used by NOFORK applets (e.g. cat) - must not use xmalloc */ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) { int status = -1; off_t total = 0; - char buffer[BUFSIZ]; +#if CONFIG_FEATURE_COPYBUF_KB <= 4 + char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024]; + enum { buffer_size = sizeof(buffer) }; +#else + char *buffer; + int buffer_size; + + buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, + /* ignored: */ -1, 0); + buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024; + if (buffer == MAP_FAILED) { + buffer = alloca(4 * 1024); + buffer_size = 4 * 1024; + } +#endif if (src_fd < 0) goto out; if (!size) { - size = BUFSIZ; + size = buffer_size; status = 1; /* copy until eof */ } while (1) { ssize_t rd; - rd = safe_read(src_fd, buffer, size > BUFSIZ ? BUFSIZ : size); + rd = safe_read(src_fd, buffer, size > buffer_size ? buffer_size : size); if (!rd) { /* eof - all done */ status = 0; @@ -62,6 +73,11 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) } } out: + +#if CONFIG_FEATURE_COPYBUF_KB > 4 + if (buffer_size != 4 * 1024) + munmap(buffer, buffer_size); +#endif return status ? -1 : total; } |