Friendly inactivity ping.
On Thu, 18 Apr 2019 at 17:42, Giuseppe Musacchio <[email protected]> wrote:
>
> Some PT_LOAD sections may be completely zeroed out and their p_filesize
> is zero, in that case the loader should just allocate a page that's at
> least p_memsz bytes large (plus eventual alignment padding).
>
> Calling zero_bss does this job for us, all we have to do is make sure we
> don't try to mmap a zero-length page.
>
> Signed-off-by: Giuseppe Musacchio <[email protected]>
> ---
> linux-user/elfload.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index c1a2602..e9a0951 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -2366,11 +2366,17 @@ static void load_elf_image(const char *image_name,
> int image_fd,
> vaddr_ps = TARGET_ELF_PAGESTART(vaddr);
> vaddr_len = TARGET_ELF_PAGELENGTH(eppnt->p_filesz + vaddr_po);
>
> - error = target_mmap(vaddr_ps, vaddr_len,
> - elf_prot, MAP_PRIVATE | MAP_FIXED,
> - image_fd, eppnt->p_offset - vaddr_po);
> - if (error == -1) {
> - goto exit_perror;
> + /* Some sections may be completely empty without any backing file
> + * segment, in that case just let zero_bss allocate an empty
> buffer
> + * for it. */
> + if (eppnt->p_filesz != 0) {
> + error = target_mmap(vaddr_ps, vaddr_len, elf_prot,
> + MAP_PRIVATE | MAP_FIXED,
> + image_fd, eppnt->p_offset - vaddr_po);
> +
> + if (error == -1) {
> + goto exit_perror;
> + }
> }
>
> vaddr_ef = vaddr + eppnt->p_filesz;
> --
> 2.20.1
>
