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authorRichard Henderson <rth@twiddle.net>2010-07-27 10:25:30 -0700
committerEdgar E. Iglesias <edgar.iglesias@gmail.com>2010-07-29 08:32:28 +0200
commit9955ffac9a31aad346fe7f0fcefebe88da7f9df5 (patch)
tree6717fb9286c007302a39846fd6ecb4be088c0f18 /linux-user/linuxload.c
parentd97ef72eed202460a13dfe4a92fd95ac9e6ddf11 (diff)
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linux-user: Reduce lseek+reads while loading elf files.
Define BPRM_BUF_SIZE to 1k and read that amount initially. If the data we want from the binary is in this buffer, use it instead of reading from the file again. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Diffstat (limited to 'linux-user/linuxload.c')
-rw-r--r--linux-user/linuxload.c17
1 files changed, 7 insertions, 10 deletions
diff --git a/linux-user/linuxload.c b/linux-user/linuxload.c
index 13ad9aa..9ee27c3 100644
--- a/linux-user/linuxload.c
+++ b/linux-user/linuxload.c
@@ -96,18 +96,16 @@ static int prepare_binprm(struct linux_binprm *bprm)
}
}
- retval = lseek(bprm->fd, 0L, SEEK_SET);
- if(retval >= 0) {
- retval = read(bprm->fd, bprm->buf, 128);
- }
- if(retval < 0) {
+ retval = read(bprm->fd, bprm->buf, BPRM_BUF_SIZE);
+ if (retval < 0) {
perror("prepare_binprm");
exit(-1);
- /* return(-errno); */
}
- else {
- return(retval);
+ if (retval < BPRM_BUF_SIZE) {
+ /* Make sure the rest of the loader won't read garbage. */
+ memset(bprm->buf + retval, 0, BPRM_BUF_SIZE - retval);
}
+ return retval;
}
/* Construct the envp and argv tables on the target stack. */
@@ -163,8 +161,7 @@ int loader_exec(const char * filename, char ** argv, char ** envp,
int i;
bprm->p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
- for (i=0 ; i<MAX_ARG_PAGES ; i++) /* clear page-table */
- bprm->page[i] = NULL;
+ memset(bprm->page, 0, sizeof(bprm->page));
retval = open(filename, O_RDONLY);
if (retval < 0)
return retval;