Hi,
[snip]
> > > size = stats.st_size;
> > > + if (use_mmap) {
> > > + buf = mmap(NULL, size, PROT_READ|PROT_WRITE,
> > > + MAP_PRIVATE, fd, 0);
> >
> > Probably map it as readonly is enough.
>
> Although I agree with you for the ramdisk case, I nevertheless would
> prefer to keep it writable to have the same semantics as for the
> malloc case.
>
> So do you agree with the patch below?
Michael, it looks good to me.
Reviewed-by: Dave Young <dyoung at redhat.com>
Thanks a lot.
>
> Michael
> ---
> kexec/arch/s390/kexec-image.c | 2 +-
> kexec/kexec.c | 31 ++++++++++++++++++++++++++++---
> kexec/kexec.h | 1 +
> 3 files changed, 30 insertions(+), 4 deletions(-)
>
> --- a/kexec/arch/s390/kexec-image.c
> +++ b/kexec/arch/s390/kexec-image.c
> @@ -101,7 +101,7 @@ image_s390_load(int argc, char **argv, c
> * we load the ramdisk directly behind the image with 1 MiB alignment.
> */
> if (ramdisk) {
> - rd_buffer = slurp_file(ramdisk, &ramdisk_len);
> + rd_buffer = slurp_file_mmap(ramdisk, &ramdisk_len);
> if (rd_buffer == NULL) {
> fprintf(stderr, "Could not read ramdisk.\n");
> return -1;
> --- a/kexec/kexec.c
> +++ b/kexec/kexec.c
> @@ -29,6 +29,7 @@
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <sys/reboot.h>
> +#include <sys/mman.h>
> #include <unistd.h>
> #include <fcntl.h>
> #ifndef _O_BINARY
> @@ -514,7 +515,8 @@ static char *slurp_fd(int fd, const char
> return buf;
> }
>
> -char *slurp_file(const char *filename, off_t *r_size)
> +static char *slurp_file_generic(const char *filename, off_t *r_size,
> + int use_mmap)
> {
> int fd;
> char *buf;
> @@ -552,11 +554,17 @@ char *slurp_file(const char *filename, o
> if (err < 0)
> die("Can not seek to the begin of file %s: %s\n",
> filename, strerror(errno));
> + buf = slurp_fd(fd, filename, size, &nread);
> } else {
> size = stats.st_size;
> + if (use_mmap) {
> + buf = mmap(NULL, size, PROT_READ|PROT_WRITE,
> + MAP_PRIVATE, fd, 0);
> + nread = size;
> + } else {
> + buf = slurp_fd(fd, filename, size, &nread);
> + }
> }
> -
> - buf = slurp_fd(fd, filename, size, &nread);
> if (!buf)
> die("Cannot read %s", filename);
>
> @@ -567,6 +575,23 @@ char *slurp_file(const char *filename, o
> return buf;
> }
>
> +/*
> + * Read file into malloced buffer
> + */
> +char *slurp_file(const char *filename, off_t *r_size)
> +{
> + return slurp_file_generic(filename, r_size, 0);
> +}
> +
> +/*
> + * Map "normal" file or read "character device" into malloced buffer.
> + * You must not use free, realloc, etc. with the returned buffer.
> + */
> +char *slurp_file_mmap(const char *filename, off_t *r_size)
> +{
> + return slurp_file_generic(filename, r_size, 1);
> +}
> +
> /* This functions reads either specified number of bytes from the file or
> lesser if EOF is met. */
>
> --- a/kexec/kexec.h
> +++ b/kexec/kexec.h
> @@ -253,6 +253,7 @@ extern void die(const char *fmt, ...)
> extern void *xmalloc(size_t size);
> extern void *xrealloc(void *ptr, size_t size);
> extern char *slurp_file(const char *filename, off_t *r_size);
> +extern char *slurp_file_mmap(const char *filename, off_t *r_size);
> extern char *slurp_file_len(const char *filename, off_t size, off_t *nread);
> extern char *slurp_decompress_file(const char *filename, off_t *r_size);
> extern unsigned long virt_to_phys(unsigned long addr);
>
