x86/efi: Add a "debug" option to the efi= cmdline

... and hide the memory regions dump behind it. Make it default-off.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20141209095843.GA3990@pd.tnic
Acked-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index bfcb1a62a7b48466f3cbe5a08d3e1a632eadc3d2..01aa47d3b6ab607e6a66f2a6a827b4b1afe4da73 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1036,7 +1036,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        Format: {"off" | "on" | "skip[mbr]"}
 
        efi=            [EFI]
-                       Format: { "old_map", "nochunk", "noruntime" }
+                       Format: { "old_map", "nochunk", "noruntime", "debug" }
                        old_map [X86-64]: switch to the old ioremap-based EFI
                        runtime services mapping. 32-bit still uses this one by
                        default.
@@ -1044,6 +1044,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        boot stub, as chunking can cause problems with some
                        firmware implementations.
                        noruntime : disable EFI runtime services support
+                       debug: enable misc debug output
 
        efi_no_storage_paranoia [EFI; X86]
                        Using this parameter you can use more than 50% of

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index dbc8627a5cdf6d569a5f69cbea05ebac924d2279..e859d56ce9f88661963b9ff679cb3f7b8593c9c4 100644 (file)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -491,7 +491,8 @@ void __init efi_init(void)
        if (efi_memmap_init())
                return;
 
-       print_efi_memmap();
+       if (efi_enabled(EFI_DBG))
+               print_efi_memmap();
 }
 
 void __init efi_late_init(void)
@@ -939,6 +940,8 @@ static int __init arch_parse_efi_cmdline(char *str)
 {
        if (parse_option_str(str, "old_map"))
                set_bit(EFI_OLD_MEMMAP, &efi.flags);
+       if (parse_option_str(str, "debug"))
+               set_bit(EFI_DBG, &efi.flags);
 
        return 0;
 }

diff --git a/include/linux/efi.h b/include/linux/efi.h
index cf7e431cbc730dff0ef445dc48989bf5156a09ac..af5be0368dec26c934565e634c0dc803958ed2cc 100644 (file)
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -942,6 +942,7 @@ extern int __init efi_setup_pcdp_console(char *);
 #define EFI_64BIT              5       /* Is the firmware 64-bit? */
 #define EFI_PARAVIRT           6       /* Access is via a paravirt interface */
 #define EFI_ARCH_1             7       /* First arch-specific bit */
+#define EFI_DBG                        8       /* Print additional debug info at runtime */
 
 #ifdef CONFIG_EFI
 /*