[PATCH v6 7/8] bootconfig: skip runtime kernel.* render once prepended early
From: Breno Leitao <leitao@debian.org>
Date: 2026-06-23 16:17:17
Also in:
bpf, linux-doc, linux-kbuild, lkml, llvm
Subsystem:
the rest · Maintainer:
Linus Torvalds
setup_boot_config() folds the embedded bootconfig "kernel" subtree into
the command line via xbc_make_cmdline("kernel"). A subsequent patch lets
an architecture prepend the build-time-rendered embedded "kernel" keys
to boot_command_line early in setup_arch(); rendering them again here
would then duplicate every key in saved_command_line and make
accumulating handlers (console=, earlycon=, ...) re-register the same
value.
Track whether the bootconfig data came from the embedded source
(from_embedded) and skip the runtime render only when the early prepend
actually happened, as reported by xbc_embedded_cmdline_applied(). On
architectures that do not select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG
that helper is a stub returning false, so this path is unchanged and the
embedded "kernel" keys still reach the cmdline via the runtime parser
exactly as before.
Signed-off-by: Breno Leitao <leitao@debian.org>
---
init/main.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/init/main.c b/init/main.c
index e363232b428b4..260bd5242f94e 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 +424,24 @@ 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 + * this bootconfig came from the embedded source and + * setup_arch() already prepended the rendered "kernel" subtree + * to boot_command_line, rendering again here would duplicate + * the keys in saved_command_line and make accumulating handlers + * (console=, earlycon=, ...) re-register the same value. Skip + * only when the prepend really happened. + * + * On arches that do not select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG, + * CONFIG_CMDLINE_FROM_BOOTCONFIG is unselectable and + * xbc_embedded_cmdline_applied() collapses to a stub returning + * false, so this path still runs and the embedded "kernel" + * keys reach the cmdline via the runtime parser exactly as + * before this series. + */ + if (!from_embedded || !xbc_embedded_cmdline_applied()) + extra_command_line = xbc_make_cmdline("kernel"); /* Also, "init." keys are init arguments */ extra_init_args = xbc_make_cmdline("init"); }
--
2.53.0-Meta