On Mon, 15 Jun 2020 at 13:58, Philipp Fent <fent@xxxxxxxxx> wrote:
>
> Commit 9302c1bb8e47 ("efi/libstub: Rewrite file I/O routine") introduced a
> regression that made a couple of (badly configured) systems fail to
> boot [1]: Until 5.6, we silently accepted Unix-style file separators in
> EFI paths, which might violate the EFI standard, but are an easy to make
> mistake. This fix restores the pre-5.7 behaviour.
>
> [1] https://bbs.archlinux.org/viewtopic.php?id=256273
>
> Signed-off-by: Philipp Fent <fent@xxxxxxxxx>
Apologies for the breakage. I will queue this as a fix.
> ---
> drivers/firmware/efi/libstub/file.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c
> index 2005e33b33d5..f8a28a6e0bde 100644
> --- a/drivers/firmware/efi/libstub/file.c
> +++ b/drivers/firmware/efi/libstub/file.c
> @@ -102,11 +102,21 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len,
> if (!found)
> return 0;
>
> + /* Skip any leading slashes */
> + while (cmdline[i] == L'/' || cmdline[i] == L'\\')
> + i++;
> +
> while (--result_len > 0 && i < cmdline_len) {
> if (cmdline[i] == L'\0' ||
> cmdline[i] == L'\n' ||
> cmdline[i] == L' ')
> break;
> + /* Replace UNIX dir separators with EFI standard separators */
> + if (cmdline[i] == L'/') {
> + *result++ = L'\\';
> + i++;
> + continue;
> + }
Any objections if I change this to
---%<---
efi_char16_t c = cmdline[i++];
if (c == L'\0' || c == L'\n' || c == L' ')
break;
else if (c == L'/')
/* Replace UNIX dir separators with EFI standard ones */
*result++ = L'\\';
else
*result++ = c;
---%<---
(no need to resend)
> *result++ = cmdline[i++];
> }
> *result = L'\0';
> --
> 2.27.0
>
