fix double-processing of DT_RELR relocations in ldso relocating itself

[musl] / src / stdio / __stdio_read.c

diff --git a/src/stdio/__stdio_read.c b/src/stdio/__stdio_read.c
index a2e4cd6..ea675da 100644 (file)
--- a/src/stdio/__stdio_read.c
+++ b/src/stdio/__stdio_read.c
@@ -1,22 +1,24 @@
 #include "stdio_impl.h"
+#include <sys/uio.h>
 
 size_t __stdio_read(FILE *f, unsigned char *buf, size_t len)
 {
        struct iovec iov[2] = {
-               { .iov_base = buf, .iov_len = len },
+               { .iov_base = buf, .iov_len = len - !!f->buf_size },
                { .iov_base = f->buf, .iov_len = f->buf_size }
        };
        ssize_t cnt;
 
-       cnt = syscall(SYS_readv, f->fd, iov, 2);
+       cnt = iov[0].iov_len ? syscall(SYS_readv, f->fd, iov, 2)
+               : syscall(SYS_read, f->fd, iov[1].iov_base, iov[1].iov_len);
        if (cnt <= 0) {
-               f->flags |= F_EOF ^ ((F_ERR^F_EOF) & cnt);
-               f->rpos = f->rend = 0;
-               return cnt;
+               f->flags |= cnt ? F_ERR : F_EOF;
+               return 0;
        }
-       if (cnt <= len) return cnt;
-       cnt -= len;
+       if (cnt <= iov[0].iov_len) return cnt;
+       cnt -= iov[0].iov_len;
        f->rpos = f->buf;
        f->rend = f->buf + cnt;
+       if (f->buf_size) buf[len-1] = *f->rpos++;
        return len;
 }