Call xbc_prepend_embedded_cmdline() in setup_arch() right after the
CONFIG_CMDLINE merge and before strscpy(command_line, ...) so the
build-time-rendered embedded bootconfig "kernel" subtree is part of
boot_command_line by the time parse_early_param() runs. early_param()
handlers (mem=, earlycon=, loglevel=, ...) now see values supplied via
CONFIG_BOOT_CONFIG_EMBED_FILE without parsing bootconfig at runtime.
Select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG so the user-visible
CONFIG_BOOT_CONFIG_EMBED_CMDLINE option becomes selectable on x86.
With this select in place, setup_boot_config() in init/main.c would
otherwise render the embedded "kernel" subtree a second time via
xbc_make_cmdline("kernel") and prepend it to saved_command_line /
static_command_line through extra_command_line, duplicating every
embedded kernel.* key in /proc/cmdline and causing accumulating
handlers (console=, earlycon=, ...) to register the same value twice.
Track whether the bootconfig data came from the embedded source and
skip the duplicate render in that case.
Signed-off-by: Breno Leitao <leitao@debian.org>
---
arch/x86/Kconfig | 1 +
arch/x86/kernel/setup.c | 3 +++
init/main.c | 19 ++++++++++++++++---
3 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f24810015234..f839795692b4 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -126,6 +126,7 @@ config X86
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
select ARCH_SUPPORTS_CFI if X86_64
+ select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG
select ARCH_USES_CFI_TRAPS if X86_64 && CFI
select ARCH_SUPPORTS_LTO_CLANG
select ARCH_SUPPORTS_LTO_CLANG_THIN
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 46882ce79c3a..592c4c79c974 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -6,6 +6,7 @@
* parts of early kernel initialization.
*/
#include <linux/acpi.h>
+#include <linux/bootconfig.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/crash_dump.h>
@@ -924,6 +925,8 @@ void __init setup_arch(char **cmdline_p)
builtin_cmdline_added = true;
#endif
+ xbc_prepend_embedded_cmdline(boot_command_line, COMMAND_LINE_SIZE);
+
strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
diff --git a/init/main.c b/init/main.c
index e363232b428b..8264bfa97aa2 100644
--- a/init/main.c
+++ b/init/main.c
@@ -378,12 +378,15 @@ static void __init setup_boot_config(void)
int pos, ret;
size_t size;
char *err;
+ bool from_embedded = false;
/* Cut out the bootconfig data even if we have no bootconfig option */
data = get_boot_config_from_initrd(&size);
/* If there is no bootconfig in initrd, try embedded one. */
- if (!data)
+ if (!data) {
data = xbc_get_embedded_bootconfig(&size);
+ from_embedded = true;
+ }
strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,@@ -421,8 +424,18 @@ static void __init setup_boot_config(void)
} else {
xbc_get_info(&ret, NULL);
pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
- /* keys starting with "kernel." are passed via cmdline */
- extra_command_line = xbc_make_cmdline("kernel");
+ /*
+ * keys starting with "kernel." are passed via cmdline. When
+ * BOOT_CONFIG_EMBED_CMDLINE is enabled and this bootconfig
+ * came from the embedded source, setup_arch() already
+ * prepended the rendered "kernel" subtree to
+ * boot_command_line; rendering again here would duplicate
+ * the keys in saved_command_line / static_command_line and
+ * cause accumulating handlers (console=, earlycon=, ...) to
+ * re-register the same value.
+ */
+ if (!IS_ENABLED(CONFIG_BOOT_CONFIG_EMBED_CMDLINE) || !from_embedded)
+ extra_command_line = xbc_make_cmdline("kernel");
/* Also, "init." keys are init arguments */
extra_init_args = xbc_make_cmdline("init");
}
--
2.54.0