From: H. Peter Anvin <hpa@xxxxxxxxx> Instead of using CONFIG_PHYSICAL_ALIGN and CONFIG_PHYSICAL_START directly, use LOAD_PHYSICAL_ALIGN (CONFIG_PHYSICAL_ALIGN or the smallest valid number, whichever is greater) and LOAD_PHYSICAL_ADDR (CONFIG_PHYSICAL_START rounded up to the nearest alignment datum) for both 32 and 64-bit mode. [ Impact: Avoids problems in case of kernel misconfiguration ] Signed-off-by: H. Peter Anvin <hpa at zytor.com> --- arch/x86/boot/compressed/head_32.S | 4 ++-- arch/x86/boot/compressed/head_64.S | 21 +++++++++------------ arch/x86/boot/header.S | 2 +- arch/x86/include/asm/boot.h | 13 +++++++++++-- 4 files changed, 23 insertions(+), 17 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 31fc6dc..2d7cd0f 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -70,8 +70,8 @@ ENTRY(startup_32) jbe 1f movl %eax, %ebx 1: - addl $(CONFIG_PHYSICAL_ALIGN - 1), %ebx - andl $(~(CONFIG_PHYSICAL_ALIGN - 1)), %ebx + addl $(LOAD_PHYSICAL_ALIGN - 1), %ebx + andl $(~(LOAD_PHYSICAL_ALIGN - 1)), %ebx #else movl $LOAD_PHYSICAL_ADDR, %ebx #endif diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index f4ddd02..201af02 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -22,7 +22,6 @@ #include <linux/linkage.h> #include <asm/segment.h> #include <asm/pgtable_types.h> -#include <asm/page_types.h> #include <asm/boot.h> #include <asm/msr.h> #include <asm/processor-flags.h> @@ -72,19 +71,17 @@ ENTRY(startup_32) * contains the address where we should move the kernel image temporarily * for safe in-place decompression. */ -ALIGN_MASK = (CONFIG_PHYSICAL_ALIGN-1) | (PMD_PAGE_SIZE-1) - #ifdef CONFIG_RELOCATABLE - movl $CONFIG_PHYSICAL_START, %eax + movl $LOAD_PHYSICAL_ADDR, %eax movl %ebp, %ebx - addl $ALIGN_MASK, %ebx - andl $~ALIGN_MASK, %ebx + addl $(LOAD_PHYSICAL_ALIGN - 1), %ebx + andl $~(LOAD_PHYSICAL_ALIGN - 1), %ebx cmpl %ebx, %eax jbe 1f movl %eax, %ebx 1: #else - movl $CONFIG_PHYSICAL_START, %ebx + movl $LOAD_PHYSICAL_ADDR, %ebx #endif /* Replace the compressed data size with the uncompressed size */ @@ -216,21 +213,21 @@ ENTRY(startup_64) * * If it is a relocatable kernel then decompress and run the kernel * from load address aligned to 2MB addr, otherwise decompress and - * run the kernel from CONFIG_PHYSICAL_START + * run the kernel from LOAD_PHYSICAL_ADDR */ /* Start with the delta to where the kernel will run at. */ #ifdef CONFIG_RELOCATABLE leaq startup_32(%rip) /* - $startup_32 */, %rbp - movq $CONFIG_PHYSICAL_START, %rax - addq $ALIGN_MASK, %rbp - andq $~ALIGN_MASK, %rbp + movq $LOAD_PHYSICAL_ADDR, %rax + addq $(LOAD_PHYSICAL_ALIGN - 1), %rbp + andq $~(LOAD_PHYSICAL_ALIGN - 1), %rbp cmpq %rbp, %rax jbe 1f movq %rax, %rbp 1: #else - movq $CONFIG_PHYSICAL_START, %rbp + movq $LOAD_PHYSICAL_ADDR, %rbp #endif movq %rbp, %rbx diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S index 5d84d1c..cfd3bc4 100644 --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -192,7 +192,7 @@ ramdisk_max: .long 0x7fffffff # but leave it at 2 GB to avoid # possible bootloader bugs. -kernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment +kernel_alignment: .long LOAD_PHYSICAL_ALIGN #physical addr alignment #required for protected mode #kernel #ifdef CONFIG_RELOCATABLE diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h index 6ba23dd..641debb 100644 --- a/arch/x86/include/asm/boot.h +++ b/arch/x86/include/asm/boot.h @@ -8,10 +8,19 @@ #ifdef __KERNEL__ +#include <asm/page_types.h> + +/* Permitted physical alignment of the kernel */ +#if defined(CONFIG_X86_64) && CONFIG_PHYSICAL_ALIGN < PMD_PAGE_SIZE +#define LOAD_PHYSICAL_ALIGN PMD_PAGE_SIZE +#else +#define LOAD_PHYSICAL_ALIGN CONFIG_PHYSICAL_ALIGN +#endif + /* Physical address where kernel should be loaded. */ #define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \ - + (CONFIG_PHYSICAL_ALIGN - 1)) \ - & ~(CONFIG_PHYSICAL_ALIGN - 1)) + + (LOAD_PHYSICAL_ALIGN - 1)) \ + & ~(LOAD_PHYSICAL_ALIGN - 1)) #ifdef CONFIG_KERNEL_BZIP2 #define BOOT_HEAP_SIZE 0x400000 -- 1.6.0.6
