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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-19 19:11:10 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-19 19:11:10 -0800
commit5abcd76f5d896de014bd8d1486107c483659d40d (patch)
tree04d960c785e40300e800593826c9b1fa2137d2a5 /arch/x86/include
parenta57ed93600f2dab64e859d524c3320fe0922e99d (diff)
parent5dcd14ecd41ea2b3ae3295a9b30d98769d52165f (diff)
Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 bootup changes from Ingo Molnar: "Deal with bootloaders which fail to initialize unknown fields in boot_params to zero, by sanitizing boot params passed in. This unbreaks versions of kexec-utils. Other bootloaders do not appear to show sensitivity to this change, but it's a possibility for breakage nevertheless." * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, boot: Sanitize boot_params if not zeroed on creation
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/bootparam_utils.h38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h
new file mode 100644
index 000000000000..5b5e9cb774b5
--- /dev/null
+++ b/arch/x86/include/asm/bootparam_utils.h
@@ -0,0 +1,38 @@
+#ifndef _ASM_X86_BOOTPARAM_UTILS_H
+#define _ASM_X86_BOOTPARAM_UTILS_H
+
+#include <asm/bootparam.h>
+
+/*
+ * This file is included from multiple environments. Do not
+ * add completing #includes to make it standalone.
+ */
+
+/*
+ * Deal with bootloaders which fail to initialize unknown fields in
+ * boot_params to zero. The list fields in this list are taken from
+ * analysis of kexec-tools; if other broken bootloaders initialize a
+ * different set of fields we will need to figure out how to disambiguate.
+ *
+ */
+static void sanitize_boot_params(struct boot_params *boot_params)
+{
+ if (boot_params->sentinel) {
+ /*fields in boot_params are not valid, clear them */
+ memset(&boot_params->olpc_ofw_header, 0,
+ (char *)&boot_params->alt_mem_k -
+ (char *)&boot_params->olpc_ofw_header);
+ memset(&boot_params->kbd_status, 0,
+ (char *)&boot_params->hdr -
+ (char *)&boot_params->kbd_status);
+ memset(&boot_params->_pad7[0], 0,
+ (char *)&boot_params->edd_mbr_sig_buffer[0] -
+ (char *)&boot_params->_pad7[0]);
+ memset(&boot_params->_pad8[0], 0,
+ (char *)&boot_params->eddbuf[0] -
+ (char *)&boot_params->_pad8[0]);
+ memset(&boot_params->_pad9[0], 0, sizeof(boot_params->_pad9));
+ }
+}
+
+#endif /* _ASM_X86_BOOTPARAM_UTILS_H */