commit c83a9d5e425d4678b05ca058fec6254f18601474
author Fenghua Yu <fenghua.yu@intel.com> Tue Mar 19 08:04:44 2013 -0700
committer H. Peter Anvin <hpa@zytor.com> Tue Mar 19 19:51:08 2013 -0700
tree 9fcab0ae6fa17816496cd7e1a16f0708dee3f660
parent 66db3feb486c01349f767b98ebb10b0c3d2d021b

x86-32, microcode_intel_early: Fix crash with CONFIG_DEBUG_VIRTUAL

In 32-bit, __pa_symbol() in CONFIG_DEBUG_VIRTUAL accesses kernel data
(e.g.  max_low_pfn) that not only hasn't been setup yet in such early
boot phase, but since we are in linear mode, cannot even be detected
as uninitialized.

Thus, use __pa_nodebug() rather than __pa_symbol() to get a global
symbol's physical address.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1363705484-27645-1-git-send-email-fenghua.yu@intel.com
Reported-and-tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/microcode_intel_early.c

diff --git a/arch/x86/kernel/microcode_intel_early.c b/arch/x86/kernel/microcode_intel_early.c
index 7890bc8..5992ee8 100644
--- a/arch/x86/kernel/microcode_intel_early.c
+++ b/arch/x86/kernel/microcode_intel_early.c
@@ -90,13 +90,13 @@
 	struct microcode_intel ***mc_saved;
 
 	mc_saved = (struct microcode_intel ***)
-		   __pa_symbol(&mc_saved_data->mc_saved);
+		   __pa_nodebug(&mc_saved_data->mc_saved);
 	for (i = 0; i < mc_saved_data->mc_saved_count; i++) {
 		struct microcode_intel *p;
 
 		p = *(struct microcode_intel **)
-			__pa(mc_saved_data->mc_saved + i);
-		mc_saved_tmp[i] = (struct microcode_intel *)__pa(p);
+			__pa_nodebug(mc_saved_data->mc_saved + i);
+		mc_saved_tmp[i] = (struct microcode_intel *)__pa_nodebug(p);
 	}
 }
 #endif
@@ -562,7 +562,7 @@
 	struct cpio_data cd;
 	long offset = 0;
 #ifdef CONFIG_X86_32
-	char *p = (char *)__pa_symbol(ucode_name);
+	char *p = (char *)__pa_nodebug(ucode_name);
 #else
 	char *p = ucode_name;
 #endif
@@ -630,8 +630,8 @@
 	if (mc_intel == NULL)
 		return;
 
-	delay_ucode_info_p = (int *)__pa_symbol(&delay_ucode_info);
-	current_mc_date_p = (int *)__pa_symbol(&current_mc_date);
+	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
+	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
 
 	*delay_ucode_info_p = 1;
 	*current_mc_date_p = mc_intel->hdr.date;
@@ -741,15 +741,15 @@
 #ifdef CONFIG_X86_32
 	struct boot_params *boot_params_p;
 
-	boot_params_p = (struct boot_params *)__pa_symbol(&boot_params);
+	boot_params_p = (struct boot_params *)__pa_nodebug(&boot_params);
 	ramdisk_image = boot_params_p->hdr.ramdisk_image;
 	ramdisk_size  = boot_params_p->hdr.ramdisk_size;
 	initrd_start_early = ramdisk_image;
 	initrd_end_early = initrd_start_early + ramdisk_size;
 
 	_load_ucode_intel_bsp(
-		(struct mc_saved_data *)__pa_symbol(&mc_saved_data),
-		(unsigned long *)__pa_symbol(&mc_saved_in_initrd),
+		(struct mc_saved_data *)__pa_nodebug(&mc_saved_data),
+		(unsigned long *)__pa_nodebug(&mc_saved_in_initrd),
 		initrd_start_early, initrd_end_early, &uci);
 #else
 	ramdisk_image = boot_params.hdr.ramdisk_image;
@@ -772,10 +772,10 @@
 	unsigned long *initrd_start_p;
 
 	mc_saved_in_initrd_p =
-		(unsigned long *)__pa_symbol(mc_saved_in_initrd);
-	mc_saved_data_p = (struct mc_saved_data *)__pa_symbol(&mc_saved_data);
-	initrd_start_p = (unsigned long *)__pa_symbol(&initrd_start);
-	initrd_start_addr = (unsigned long)__pa_symbol(*initrd_start_p);
+		(unsigned long *)__pa_nodebug(mc_saved_in_initrd);
+	mc_saved_data_p = (struct mc_saved_data *)__pa_nodebug(&mc_saved_data);
+	initrd_start_p = (unsigned long *)__pa_nodebug(&initrd_start);
+	initrd_start_addr = (unsigned long)__pa_nodebug(*initrd_start_p);
 #else
 	mc_saved_data_p = &mc_saved_data;
 	mc_saved_in_initrd_p = mc_saved_in_initrd;