[PATCH 5.15 063/128] Revert "x86/boot: Pull up cmdline preparation and early param parsing"

Greg Kroah-Hartman
2021-12-27T15:52:46Z

From: Borislav Petkov <bp@suse.de>

commit fbe6183998546f8896ee0b620ece86deff5a2fd1 upstream.

This reverts commit 8d48bf8206f77aa8687f0e241e901e5197e52423.

It turned out to be a bad idea as it broke supplying mem= cmdline
parameters due to parse_memopt() requiring preparatory work like setting
up the e820 table in e820__memory_setup() in order to be able to exclude
the range specified by mem=.

Pulling that up would've broken Xen PV again, see threads at

https://lkml.kernel.org/r/20210920120421.29276-1-jgross@suse.com

due to xen_memory_setup() needing the first reservations in
early_reserve_memory() - kernel and initrd - to have happened already.

This could be fixed again by having Xen do those reservations itself...

Long story short, revert this and do a simpler fix in a later patch.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211213112757.2612-3-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/setup.c | 66 +++++++++++++++++++-----------------------------
1 file changed, 27 insertions(+), 39 deletions(-)

--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -742,28 +742,6 @@ dump_kernel_offset(struct notifier_block
return 0;
}

-static char *prepare_command_line(void)
-{
-#ifdef CONFIG_CMDLINE_BOOL
-#ifdef CONFIG_CMDLINE_OVERRIDE
- strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
-#else
- if (builtin_cmdline[0]) {
- /* append boot loader cmdline to builtin */
- strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
- strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
- strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
- }
-#endif
-#endif
-
- strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
-
- parse_early_param();
-
- return command_line;
-}
-
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
@@ -853,23 +831,6 @@ void __init setup_arch(char **cmdline_p)
x86_init.oem.arch_setup();

/*
- * x86_configure_nx() is called before parse_early_param() (called by
- * prepare_command_line()) to detect whether hardware doesn't support
- * NX (so that the early EHCI debug console setup can safely call
- * set_fixmap()). It may then be called again from within noexec_setup()
- * during parsing early parameters to honor the respective command line
- * option.
- */
- x86_configure_nx();
-
- /*
- * This parses early params and it needs to run before
- * early_reserve_memory() because latter relies on such settings
- * supplied as early params.
- */
- *cmdline_p = prepare_command_line();
-
- /*
* Do some memory reservations *before* memory is added to memblock, so
* memblock allocations won't overwrite it.
*
@@ -902,6 +863,33 @@ void __init setup_arch(char **cmdline_p)
bss_resource.start = __pa_symbol(__bss_start);
bss_resource.end = __pa_symbol(__bss_stop)-1;

+#ifdef CONFIG_CMDLINE_BOOL
+#ifdef CONFIG_CMDLINE_OVERRIDE
+ strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+#else
+ if (builtin_cmdline[0]) {
+ /* append boot loader cmdline to builtin */
+ strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
+ strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+ strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+ }
+#endif
+#endif
+
+ strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
+ *cmdline_p = command_line;
+
+ /*
+ * x86_configure_nx() is called before parse_early_param() to detect
+ * whether hardware doesn't support NX (so that the early EHCI debug
+ * console setup can safely call set_fixmap()). It may then be called
+ * again from within noexec_setup() during parsing early parameters
+ * to honor the respective command line option.
+ */
+ x86_configure_nx();
+
+ parse_early_param();
+
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* Memory used by the kernel cannot be hot-removed because Linux