X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=libbb%2Fcopyfd.c;h=c5f8b5b8763a12437be5e74607e5587e67bde9d3;hb=9579d87be4ab9b02195749c15a2112e2a4466ab4;hp=aa8fbb967f61956c77ff4229cf487b9eb8db3498;hpb=335b63d8d1876ce4e172ebcc9d64544785682244;p=oweals%2Fbusybox.git

diff --git a/libbb/copyfd.c b/libbb/copyfd.c
index aa8fbb967..c5f8b5b87 100644
--- a/libbb/copyfd.c
+++ b/libbb/copyfd.c
@@ -9,32 +9,44 @@
 
 #include "libbb.h"
 
-#if BUFSIZ < 4096
-#undef BUFSIZ
-#define BUFSIZ 4096
-#endif
-
-/* Used by NOFORK applets (e.g. cat) - must be very careful
- * when calling xfuncs, allocating memory, with signals, termios, etc... */
+/* 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;
-	RESERVE_CONFIG_BUFFER(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;
+
+	/* We want page-aligned buffer, just in case kernel is clever
+	 * and can do page-aligned io more efficiently */
+	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;
@@ -63,13 +75,17 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
 		}
 	}
  out:
-	RELEASE_CONFIG_BUFFER(buffer);
+
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+	if (buffer_size != 4 * 1024)
+		munmap(buffer, buffer_size);
+#endif
 	return status ? -1 : total;
 }
 
 
 #if 0
-void complain_copyfd_and_die(off_t sz)
+void FAST_FUNC complain_copyfd_and_die(off_t sz)
 {
 	if (sz != -1)
 		bb_error_msg_and_die("short read");
@@ -78,7 +94,7 @@ void complain_copyfd_and_die(off_t sz)
 }
 #endif
 
-off_t bb_copyfd_size(int fd1, int fd2, off_t size)
+off_t FAST_FUNC bb_copyfd_size(int fd1, int fd2, off_t size)
 {
 	if (size) {
 		return bb_full_fd_action(fd1, fd2, size);
@@ -86,7 +102,7 @@ off_t bb_copyfd_size(int fd1, int fd2, off_t size)
 	return 0;
 }
 
-void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
+void FAST_FUNC bb_copyfd_exact_size(int fd1, int fd2, off_t size)
 {
 	off_t sz = bb_copyfd_size(fd1, fd2, size);
 	if (sz == size)
@@ -97,7 +113,7 @@ void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
 	xfunc_die();
 }
 
-off_t bb_copyfd_eof(int fd1, int fd2)
+off_t FAST_FUNC bb_copyfd_eof(int fd1, int fd2)
 {
 	return bb_full_fd_action(fd1, fd2, 0);
 }