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authorBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2008-05-26 15:12:01 +0000
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2008-05-26 15:12:01 +0000
commitcf18010ca966aa2be06e0466aeb78b54d15957e2 (patch)
tree3df37379ce244c74b54c04398f31f630e334409e
parentdc5d7fec350532d191ecfef49fa8b9b208b09f9f (diff)
downloadbusybox-cf18010ca966aa2be06e0466aeb78b54d15957e2.tar.gz
- use mmap instead of allocating hundreds of megabytes of RAM. +39b
-rw-r--r--modutils/depmod.c63
1 files changed, 43 insertions, 20 deletions
diff --git a/modutils/depmod.c b/modutils/depmod.c
index 489a0330e..5d51ba450 100644
--- a/modutils/depmod.c
+++ b/modutils/depmod.c
@@ -11,6 +11,12 @@
#include <libbb.h>
#include <sys/utsname.h> /* uname() */
+/*
+ * Theory of operation:
+ * - iterate over all modules and record their full path
+ * - iterate over all modules looking for "depends=" entries
+ * for each depends, look through our list of full paths and emit if found
+ */
struct globals {
llist_t *lst;
};
@@ -25,40 +31,56 @@ static int fill_lst(const char *modulename, struct stat ATTRIBUTE_UNUSED *sb,
return TRUE;
}
-static int fileAction(const char *fname, struct stat ATTRIBUTE_UNUSED *sb,
+static int fileAction(const char *fname, struct stat *sb,
void *data, int ATTRIBUTE_UNUSED depth)
{
- size_t seen = 0;
- size_t len = MAXINT(ssize_t);
- void *the_module = xmalloc_open_read_close(fname, &len), *ptr = the_module;
- const char *deps;
- RESERVE_CONFIG_BUFFER(depends, 512);
- RESERVE_CONFIG_BUFFER(buf1, 512);
-
- memset(depends, 0, sizeof(depends));
+ size_t len = sb->st_size;
+ void *the_module, *ptr;
+ int fd;
+ char *depends, *deps;
+/*XXX: FIXME: does not handle compressed modules!
+ * There should be a function that looks at the extension and sets up
+ * open_transformer for us.
+ */
if (last_char_is(fname, 'o') == NULL) /* not a module */
- goto done;
+ goto skip;
+
+ fd = xopen(fname, O_RDONLY);
+ the_module = mmap(NULL, len, PROT_READ, MAP_SHARED
+#if defined MAP_POPULATE
+ |MAP_POPULATE
+#endif
+ , fd, 0);
+ close(fd);
+ if (the_module == MAP_FAILED)
+ bb_perror_msg_and_die("mmap");
+
+ ptr = the_module;
+
fprintf((FILE*)data, "\n%s:", fname);
-//bb_info_msg("[%d] fname='%s'", (int)data, fname);
+//bb_info_msg("fname='%s'", fname);
do {
/* search for a 'd' */
- ptr = memchr(ptr, 'd', len - seen);
+ ptr = memchr(ptr, 'd', len);
if (ptr == NULL) /* no d left, done */
+ goto done;
+ if (memcmp(ptr, "depends=", sizeof("depends=")-1) == 0)
break;
- if (sscanf(ptr, "depends=%s", depends) == 1)
- break;
- seen = ++ptr - the_module;
+ len -= ++ptr - the_module;
} while (1);
+ deps = depends = strdup (ptr + sizeof("depends=")-1);
//bb_info_msg(" depends='%s'", depends);
- deps = depends;
while (*deps) {
llist_t * _lst = G.lst;
+ char *buf1;
+
ptr = strchr(deps, ',');
if (ptr != NULL)
*(char*)ptr = '\0';
/* remember the length of the current dependency plus eventual 0 byte */
len = strlen(deps) + (ptr != NULL);
+ buf1 = xmalloc(len + 3);
sprintf(buf1, "/%s.", deps); /* make sure we match the correct file */
while (_lst) {
ptr = strstr(_lst->data, buf1);
@@ -66,16 +88,17 @@ static int fileAction(const char *fname, struct stat ATTRIBUTE_UNUSED *sb,
break; /* found it */
_lst = _lst->link;
}
- if (_lst && _lst->data) {
+ free(buf1);
+ if (_lst /*&& _lst->data*/) {
//bb_info_msg("[%s] -> '%s'", deps, _lst->data);
fprintf((FILE*)data, " %s", _lst->data);
deps += len;
}
}
+ free(depends);
done:
- RELEASE_CONFIG_BUFFER(depends);
- RELEASE_CONFIG_BUFFER(buf1);
- free(the_module);
+ munmap(the_module, sb->st_size);
+skip:
return TRUE;
}