On Wed, Mar 31, 2021 at 06:10:08PM +0200, Ard Biesheuvel wrote:
> (+ Arvind)
>
> On Tue, 30 Mar 2021 at 19:57, Daniel Walker <danielwa@xxxxxxxxx> wrote:
> >
> > This adds code to handle the generic command line changes.
> > The efi code appears that it doesn't benefit as much from this design
> > as it could.
> >
> > For example, if you had a prepend command line with "nokaslr" then
> > you might be helpful to re-enable it in the boot loader or dts,
> > but there appears to be no way to re-enable kaslr or some of the
> > other options.
> >
> > Cc: xe-linux-external@xxxxxxxxx
> > Signed-off-by: Daniel Walker <danielwa@xxxxxxxxx>
> > ---
> > .../firmware/efi/libstub/efi-stub-helper.c | 35 +++++++++++++++++++
> > drivers/firmware/efi/libstub/efi-stub.c | 7 ++++
> > drivers/firmware/efi/libstub/efistub.h | 1 +
> > drivers/firmware/efi/libstub/x86-stub.c | 13 +++++--
> > 4 files changed, 54 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
> > index aa8da0a49829..c155837cedc9 100644
> > --- a/drivers/firmware/efi/libstub/efi-stub-helper.c
> > +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
> > @@ -13,6 +13,7 @@
> > #include <linux/efi.h>
> > #include <linux/kernel.h>
> > #include <linux/printk.h> /* For CONSOLE_LOGLEVEL_* */
> > +#include <linux/cmdline.h>
> > #include <asm/efi.h>
> > #include <asm/setup.h>
> >
> > @@ -172,6 +173,40 @@ int efi_printk(const char *fmt, ...)
> > return printed;
> > }
> >
> > +/**
> > + * efi_handle_cmdline() - handle adding in building parts of the command line
> > + * @cmdline: kernel command line
> > + *
> > + * Add in the generic parts of the commandline and start the parsing of the
> > + * command line.
> > + *
> > + * Return: status code
> > + */
> > +efi_status_t efi_handle_cmdline(char const *cmdline)
> > +{
> > + efi_status_t status;
> > +
> > + status = efi_parse_options(CMDLINE_PREPEND);
> > + if (status != EFI_SUCCESS) {
> > + efi_err("Failed to parse options\n");
> > + return status;
> > + }
>
> Even though I am not a fan of the 'success handling' pattern,
> duplicating the exact same error handling three times is not great
> either. Could we reuse more of the code here?
How about
efi_status_t status = 0;
status |= efi_parse_options(CMDLINE_PREPEND);
then error checking once ?
> > +
> > + status = efi_parse_options(IS_ENABLED(CONFIG_CMDLINE_OVERRIDE) ? "" : cmdline);
>
> What is the point of calling efi_parse_options() with an empty string?
I could change it to if ((IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) ?
> > --- a/drivers/firmware/efi/libstub/efi-stub.c
> > +++ b/drivers/firmware/efi/libstub/efi-stub.c
> > @@ -172,6 +172,12 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
> > goto fail;
> > }
> >
> > +#ifdef CONFIG_GENERIC_CMDLINE
> > + status = efi_handle_cmdline(cmdline_ptr);
> > + if (status != EFI_SUCCESS) {
> > + goto fail_free_cmdline;
> > + }
> > +#else
> > if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
> > IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
>
> Does this mean CONFIG_GENERIC_CMDLINE does not replace CMDLINE_EXTEND
> / CMDLINE_FORCE etc, but introduces yet another variant on top of
> those?
>
> That does not seem like an improvement to me. I think it is great that
> you are cleaning this up, but only if it means we can get rid of the
> old implementation.
It does replace extend and force. I was under the impression this code was
shared between arm64 and arm32. If that's not the case I can delete the extend
and force section. I haven't submitted a conversion for arm32 yet.
Daniel
