[PATCH 5.15 201/279] x86/boot: Pull up cmdline preparation and early param parsing

Greg Kroah-Hartman
2021-11-24T13:58:45Z

From: Borislav Petkov <bp@suse.de>

commit 8d48bf8206f77aa8687f0e241e901e5197e52423 upstream.

Dan reports that Anjaneya Chagam can no longer use the efi=nosoftreserve
kernel command line parameter to suppress "soft reservation" behavior.

This is due to the fact that the following call-chain happens at boot:

early_reserve_memory
|-> efi_memblock_x86_reserve_range
|-> efi_fake_memmap_early

which does

if (!efi_soft_reserve_enabled())
return;

and that would have set EFI_MEM_NO_SOFT_RESERVE after having parsed
"nosoftreserve".

However, parse_early_param() gets called *after* it, leading to the boot
cmdline not being taken into account.

Therefore, carve out the command line preparation into a separate
function which does the early param parsing too. So that it all goes
together.

And then call that function before early_reserve_memory() so that the
params would have been parsed by then.

Fixes: 8aa83e6395ce ("x86/setup: Call early_reserve_memory() earlier")
Reported-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Anjaneya Chagam <anjaneya.chagam@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/e8dd8993c38702ee6dd73b3c11f158617e665607.camel@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/setup.c | 66 ++++++++++++++++++++++++++++--------------------
1 file changed, 39 insertions(+), 27 deletions(-)

--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -742,6 +742,28 @@ 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
@@ -831,6 +853,23 @@ 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.
*
@@ -863,33 +902,6 @@ 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