x86/boot: Pull up cmdline preparation and early param parsing

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

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 49b596d..c410be7 100644 (file)
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -742,6 +742,28 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
        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