linux-kernel - [PATCH] x86/setup: Deal with "quiet" commandline option earlier

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Date:   Tue,  4 Sep 2018 16:42:25 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H . Peter Anvin" <hpa@...or.com>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Cc:     Hans de Goede <hdegoede@...hat.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org, Steven Rostedt <rostedt@...dmis.org>,
        Petr Mladek <pmladek@...e.com>,
        Maninder Singh <maninder1.s@...sung.com>
Subject: [PATCH] x86/setup: Deal with "quiet" commandline option earlier

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:

[    0.000000] BIOS-provided physical RAM map:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x0000000000057fff] usable
...
[    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@...e.com>
Cc: Maninder Singh <maninder1.s@...sung.com>
Fixes: 375899cddcbb ("printk: make sure to print log on console.")
Signed-off-by: Hans de Goede <hdegoede@...hat.com>
---
 arch/x86/kernel/setup.c | 11 +++++++++++
 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 @@
 #include <asm/processor.h>
 #include <asm/bugs.h>
 #include <asm/kasan.h>
+#include <asm/cmdline.h>
 
 #include <asm/vsyscall.h>
 #include <asm/cpu.h>
@@ -864,6 +865,16 @@ void __init setup_arch(char **cmdline_p)
 	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
 #endif
 
+#if !defined CONFIG_CMDLINE_BOOL || !defined CONFIG_CMDLINE_OVERRIDE
+	/*
+	 * We call parse_early_param() somewhat late, see x86_configure_nx()
+	 * comment. Deal with "quiet" here to suppress printing of early
+	 * boot messages when quiet has been requested.
+	 */
+	if (cmdline_find_option_bool(boot_command_line, "quiet"))
+		console_loglevel = CONSOLE_LOGLEVEL_QUIET;
+#endif
+
 	/*
 	 * If we have OLPC OFW, we might end up relocating the fixmap due to
 	 * reserve_top(), so do this before touching the ioremap area.
-- 
2.19.0.rc0