Re: [PATCH] x86/setup: Deal with "quiet" commandline option earlier

[Hans de Goede]

Hi,

On 04-09-18 17:25, Hans de Goede wrote:
> Hi,
>
> On 04-09-18 16:42, Hans de Goede wrote:
> > X86's setup_arch() calls parse_early_param() somewhat late, to make
> > sure that everything is setup correcty to deal with earlyprintk over
> > the EHCI debug port.
> >
> > This means that a number of pr_info-s get done before
> > "early_param("quiet", quiet_kernel)" from init/main.c gets processed.
> >
> > Until commit 375899cddcbb ("printk: make sure to print log on console.")
> > this was not a problem because the printk code would evaluate the
> > console_loglevel vs the message-loglevel when flushing the buffer.
> >
> > After this commit the check is done at the time that pr_info is actually
> > called and the console_loglevel at calling time.
> >
> > This causes the following messages to get printed with the "quiet" option:
> >
> > [ÂÂÂ 0.000000] BIOS-provided physical RAM map:
> > [ÂÂÂ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x0000000000057fff] usable
> > ...
> > [ÂÂÂ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x0000000874ffffff] usable
> >
> > This commit fixes this by making x86's setup_arch() explicitly check for
> > quiet early on.
> >
> > Cc: Petr Mladek <pmladek@xxxxxxxx>
> > Cc: Maninder Singh <maninder1.s@xxxxxxxxxxx>
> > Fixes: 375899cddcbb ("printk: make sure to print log on console.")
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>
> Self-nack, I accidentally still had the revert of commit
> 375899cddcbb ("printk: make sure to print log on console.") in
> my tree while testingâ
>
> In order for my approach to work, we need to deal with the quiet
> option even earlier, before the first pr_notice in init/main.c,
> which requires access to the commandline before setup_arch()
> which is the function which fills the boot_command_line on
> several architectures.
>
> So I think we need to look at a different approach.
>
> I have one more idea, if that does not work out I think we
> just need to revert 375899cddcbb ("printk: make sure to print log on console.")

Ok, I have come up with a better, arch neutral fix, which no fully
lives in printk.c. I will keep the To/Cc of the new patch the same
to keep everyone in the loop.

Regards,

Hans


> > ---
> > Â arch/x86/kernel/setup.c | 11 +++++++++++
> > Â 1 file changed, 11 insertions(+)
> >
> > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> > index b4866badb235..38f66b14cf3d 100644
> > --- a/arch/x86/kernel/setup.c
> > +++ b/arch/x86/kernel/setup.c
> > @@ -93,6 +93,7 @@
> > Â #include <asm/processor.h>
> > Â #include <asm/bugs.h>
> > Â #include <asm/kasan.h>
> > +#include <asm/cmdline.h>
> > Â #include <asm/vsyscall.h>
> > Â #include <asm/cpu.h>
> > @@ -864,6 +865,16 @@ void __init setup_arch(char **cmdline_p)
> > ÂÂÂÂÂ boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
> > Â #endif
> > +#if !defined CONFIG_CMDLINE_BOOL || !defined CONFIG_CMDLINE_OVERRIDE
> > +ÂÂÂ /*
> > +ÂÂÂÂ * We call parse_early_param() somewhat late, see x86_configure_nx()
> > +ÂÂÂÂ * comment. Deal with "quiet" here to suppress printing of early
> > +ÂÂÂÂ * boot messages when quiet has been requested.
> > +ÂÂÂÂ */
> > +ÂÂÂ if (cmdline_find_option_bool(boot_command_line, "quiet"))
> > +ÂÂÂÂÂÂÂ console_loglevel = CONSOLE_LOGLEVEL_QUIET;
> > +#endif
> > +
> > ÂÂÂÂÂ /*
> > ÂÂÂÂÂÂ * If we have OLPC OFW, we might end up relocating the fixmap due to
> > ÂÂÂÂÂÂ * reserve_top(), so do this before touching the ioremap area.