Merge branch 'x86-kaslr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 kernel address space randomization support from Peter Anvin: "This enables kernel address space randomization for x86" * 'x86-kaslr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, kaslr: Clarify RANDOMIZE_BASE_MAX_OFFSET x86, kaslr: Remove unused including <linux/version.h> x86, kaslr: Use char array to gain sizeof sanity x86, kaslr: Add a circular multiply for better bit diffusion x86, kaslr: Mix entropy sources together as needed x86/relocs: Add percpu fixup for GNU ld 2.23 x86, boot: Rename get_flags() and check_flags() to *_cpuflags() x86, kaslr: Raise the maximum virtual address to -1 GiB on x86_64 x86, kaslr: Report kernel offset on panic x86, kaslr: Select random position from e820 maps x86, kaslr: Provide randomness functions x86, kaslr: Return location from decompress_kernel x86, boot: Move CPU flags out of cpucheck x86, relocs: Add more per-cpu gold special cases
This commit is contained in:
Linus Torvalds
@@ -20,7 +20,7 @@ targets := vmlinux.bin setup.bin setup.elf bzImage
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targets += fdimage fdimage144 fdimage288 image.iso mtools.conf
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subdir- := compressed
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setup-y += a20.o bioscall.o cmdline.o copy.o cpu.o cpucheck.o
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setup-y += a20.o bioscall.o cmdline.o copy.o cpu.o cpuflags.o cpucheck.o
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setup-y += early_serial_console.o edd.o header.o main.o mca.o memory.o
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setup-y += pm.o pmjump.o printf.o regs.o string.o tty.o video.o
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setup-y += video-mode.o version.o
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@@ -26,9 +26,8 @@
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#include <asm/boot.h>
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#include <asm/setup.h>
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#include "bitops.h"
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#include <asm/cpufeature.h>
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#include <asm/processor-flags.h>
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#include "ctype.h"
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#include "cpuflags.h"
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/* Useful macros */
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#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
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@@ -307,14 +306,7 @@ static inline int cmdline_find_option_bool(const char *option)
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return __cmdline_find_option_bool(cmd_line_ptr, option);
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}
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/* cpu.c, cpucheck.c */
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struct cpu_features {
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int level; /* Family, or 64 for x86-64 */
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int model;
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u32 flags[NCAPINTS];
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};
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extern struct cpu_features cpu;
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int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr);
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int validate_cpu(void);
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@@ -28,7 +28,7 @@ HOST_EXTRACFLAGS += -I$(srctree)/tools/include
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VMLINUX_OBJS = $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
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$(obj)/string.o $(obj)/cmdline.o $(obj)/early_serial_console.o \
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$(obj)/piggy.o
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$(obj)/piggy.o $(obj)/cpuflags.o $(obj)/aslr.o
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$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
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316
arch/x86/boot/compressed/aslr.c
Normal file
316
arch/x86/boot/compressed/aslr.c
Normal file
@@ -0,0 +1,316 @@
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#include "misc.h"
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#ifdef CONFIG_RANDOMIZE_BASE
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#include <asm/msr.h>
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#include <asm/archrandom.h>
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#include <asm/e820.h>
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#include <generated/compile.h>
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#include <linux/module.h>
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#include <linux/uts.h>
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#include <linux/utsname.h>
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#include <generated/utsrelease.h>
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/* Simplified build-specific string for starting entropy. */
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static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
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LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
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#define I8254_PORT_CONTROL 0x43
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#define I8254_PORT_COUNTER0 0x40
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#define I8254_CMD_READBACK 0xC0
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#define I8254_SELECT_COUNTER0 0x02
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#define I8254_STATUS_NOTREADY 0x40
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static inline u16 i8254(void)
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{
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u16 status, timer;
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do {
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outb(I8254_PORT_CONTROL,
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I8254_CMD_READBACK | I8254_SELECT_COUNTER0);
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status = inb(I8254_PORT_COUNTER0);
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timer = inb(I8254_PORT_COUNTER0);
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timer |= inb(I8254_PORT_COUNTER0) << 8;
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} while (status & I8254_STATUS_NOTREADY);
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return timer;
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}
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static unsigned long rotate_xor(unsigned long hash, const void *area,
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size_t size)
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{
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size_t i;
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unsigned long *ptr = (unsigned long *)area;
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for (i = 0; i < size / sizeof(hash); i++) {
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/* Rotate by odd number of bits and XOR. */
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hash = (hash << ((sizeof(hash) * 8) - 7)) | (hash >> 7);
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hash ^= ptr[i];
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}
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return hash;
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}
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/* Attempt to create a simple but unpredictable starting entropy. */
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static unsigned long get_random_boot(void)
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{
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unsigned long hash = 0;
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hash = rotate_xor(hash, build_str, sizeof(build_str));
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hash = rotate_xor(hash, real_mode, sizeof(*real_mode));
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return hash;
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}
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static unsigned long get_random_long(void)
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{
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#ifdef CONFIG_X86_64
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const unsigned long mix_const = 0x5d6008cbf3848dd3UL;
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#else
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const unsigned long mix_const = 0x3f39e593UL;
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#endif
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unsigned long raw, random = get_random_boot();
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bool use_i8254 = true;
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debug_putstr("KASLR using");
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if (has_cpuflag(X86_FEATURE_RDRAND)) {
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debug_putstr(" RDRAND");
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if (rdrand_long(&raw)) {
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random ^= raw;
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use_i8254 = false;
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}
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}
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if (has_cpuflag(X86_FEATURE_TSC)) {
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debug_putstr(" RDTSC");
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rdtscll(raw);
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random ^= raw;
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use_i8254 = false;
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}
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if (use_i8254) {
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debug_putstr(" i8254");
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random ^= i8254();
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}
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/* Circular multiply for better bit diffusion */
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asm("mul %3"
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: "=a" (random), "=d" (raw)
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: "a" (random), "rm" (mix_const));
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random += raw;
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debug_putstr("...\n");
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return random;
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}
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struct mem_vector {
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unsigned long start;
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unsigned long size;
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};
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#define MEM_AVOID_MAX 5
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struct mem_vector mem_avoid[MEM_AVOID_MAX];
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static bool mem_contains(struct mem_vector *region, struct mem_vector *item)
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{
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/* Item at least partially before region. */
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if (item->start < region->start)
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return false;
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/* Item at least partially after region. */
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if (item->start + item->size > region->start + region->size)
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return false;
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return true;
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}
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static bool mem_overlaps(struct mem_vector *one, struct mem_vector *two)
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{
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/* Item one is entirely before item two. */
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if (one->start + one->size <= two->start)
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return false;
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/* Item one is entirely after item two. */
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if (one->start >= two->start + two->size)
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return false;
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return true;
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}
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static void mem_avoid_init(unsigned long input, unsigned long input_size,
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unsigned long output, unsigned long output_size)
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{
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u64 initrd_start, initrd_size;
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u64 cmd_line, cmd_line_size;
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unsigned long unsafe, unsafe_len;
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char *ptr;
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/*
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* Avoid the region that is unsafe to overlap during
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* decompression (see calculations at top of misc.c).
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*/
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unsafe_len = (output_size >> 12) + 32768 + 18;
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unsafe = (unsigned long)input + input_size - unsafe_len;
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mem_avoid[0].start = unsafe;
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mem_avoid[0].size = unsafe_len;
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/* Avoid initrd. */
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initrd_start = (u64)real_mode->ext_ramdisk_image << 32;
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initrd_start |= real_mode->hdr.ramdisk_image;
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initrd_size = (u64)real_mode->ext_ramdisk_size << 32;
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initrd_size |= real_mode->hdr.ramdisk_size;
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mem_avoid[1].start = initrd_start;
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mem_avoid[1].size = initrd_size;
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/* Avoid kernel command line. */
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cmd_line = (u64)real_mode->ext_cmd_line_ptr << 32;
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cmd_line |= real_mode->hdr.cmd_line_ptr;
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/* Calculate size of cmd_line. */
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ptr = (char *)(unsigned long)cmd_line;
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for (cmd_line_size = 0; ptr[cmd_line_size++]; )
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;
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mem_avoid[2].start = cmd_line;
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mem_avoid[2].size = cmd_line_size;
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/* Avoid heap memory. */
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mem_avoid[3].start = (unsigned long)free_mem_ptr;
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mem_avoid[3].size = BOOT_HEAP_SIZE;
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/* Avoid stack memory. */
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mem_avoid[4].start = (unsigned long)free_mem_end_ptr;
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mem_avoid[4].size = BOOT_STACK_SIZE;
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}
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/* Does this memory vector overlap a known avoided area? */
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bool mem_avoid_overlap(struct mem_vector *img)
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{
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int i;
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for (i = 0; i < MEM_AVOID_MAX; i++) {
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if (mem_overlaps(img, &mem_avoid[i]))
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return true;
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}
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return false;
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}
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unsigned long slots[CONFIG_RANDOMIZE_BASE_MAX_OFFSET / CONFIG_PHYSICAL_ALIGN];
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unsigned long slot_max = 0;
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static void slots_append(unsigned long addr)
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{
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/* Overflowing the slots list should be impossible. */
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if (slot_max >= CONFIG_RANDOMIZE_BASE_MAX_OFFSET /
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CONFIG_PHYSICAL_ALIGN)
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return;
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slots[slot_max++] = addr;
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}
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static unsigned long slots_fetch_random(void)
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{
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/* Handle case of no slots stored. */
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if (slot_max == 0)
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return 0;
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return slots[get_random_long() % slot_max];
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}
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static void process_e820_entry(struct e820entry *entry,
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unsigned long minimum,
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unsigned long image_size)
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{
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struct mem_vector region, img;
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/* Skip non-RAM entries. */
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if (entry->type != E820_RAM)
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return;
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/* Ignore entries entirely above our maximum. */
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if (entry->addr >= CONFIG_RANDOMIZE_BASE_MAX_OFFSET)
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return;
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/* Ignore entries entirely below our minimum. */
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if (entry->addr + entry->size < minimum)
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return;
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region.start = entry->addr;
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region.size = entry->size;
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/* Potentially raise address to minimum location. */
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if (region.start < minimum)
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region.start = minimum;
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/* Potentially raise address to meet alignment requirements. */
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region.start = ALIGN(region.start, CONFIG_PHYSICAL_ALIGN);
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/* Did we raise the address above the bounds of this e820 region? */
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if (region.start > entry->addr + entry->size)
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return;
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/* Reduce size by any delta from the original address. */
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region.size -= region.start - entry->addr;
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/* Reduce maximum size to fit end of image within maximum limit. */
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if (region.start + region.size > CONFIG_RANDOMIZE_BASE_MAX_OFFSET)
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region.size = CONFIG_RANDOMIZE_BASE_MAX_OFFSET - region.start;
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/* Walk each aligned slot and check for avoided areas. */
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for (img.start = region.start, img.size = image_size ;
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mem_contains(®ion, &img) ;
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img.start += CONFIG_PHYSICAL_ALIGN) {
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if (mem_avoid_overlap(&img))
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continue;
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slots_append(img.start);
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}
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}
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static unsigned long find_random_addr(unsigned long minimum,
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unsigned long size)
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{
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int i;
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unsigned long addr;
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|
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/* Make sure minimum is aligned. */
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minimum = ALIGN(minimum, CONFIG_PHYSICAL_ALIGN);
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/* Verify potential e820 positions, appending to slots list. */
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for (i = 0; i < real_mode->e820_entries; i++) {
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process_e820_entry(&real_mode->e820_map[i], minimum, size);
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}
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|
||||
return slots_fetch_random();
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}
|
||||
|
||||
unsigned char *choose_kernel_location(unsigned char *input,
|
||||
unsigned long input_size,
|
||||
unsigned char *output,
|
||||
unsigned long output_size)
|
||||
{
|
||||
unsigned long choice = (unsigned long)output;
|
||||
unsigned long random;
|
||||
|
||||
if (cmdline_find_option_bool("nokaslr")) {
|
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debug_putstr("KASLR disabled...\n");
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* Record the various known unsafe memory ranges. */
|
||||
mem_avoid_init((unsigned long)input, input_size,
|
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(unsigned long)output, output_size);
|
||||
|
||||
/* Walk e820 and find a random address. */
|
||||
random = find_random_addr(choice, output_size);
|
||||
if (!random) {
|
||||
debug_putstr("KASLR could not find suitable E820 region...\n");
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* Always enforce the minimum. */
|
||||
if (random < choice)
|
||||
goto out;
|
||||
|
||||
choice = random;
|
||||
out:
|
||||
return (unsigned char *)choice;
|
||||
}
|
||||
|
||||
#endif /* CONFIG_RANDOMIZE_BASE */
|
||||
@@ -1,6 +1,6 @@
|
||||
#include "misc.h"
|
||||
|
||||
#ifdef CONFIG_EARLY_PRINTK
|
||||
#if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE
|
||||
|
||||
static unsigned long fs;
|
||||
static inline void set_fs(unsigned long seg)
|
||||
|
||||
12
arch/x86/boot/compressed/cpuflags.c
Normal file
12
arch/x86/boot/compressed/cpuflags.c
Normal file
@@ -0,0 +1,12 @@
|
||||
#ifdef CONFIG_RANDOMIZE_BASE
|
||||
|
||||
#include "../cpuflags.c"
|
||||
|
||||
bool has_cpuflag(int flag)
|
||||
{
|
||||
get_cpuflags();
|
||||
|
||||
return test_bit(flag, cpu.flags);
|
||||
}
|
||||
|
||||
#endif
|
||||
@@ -117,9 +117,11 @@ preferred_addr:
|
||||
addl %eax, %ebx
|
||||
notl %eax
|
||||
andl %eax, %ebx
|
||||
#else
|
||||
movl $LOAD_PHYSICAL_ADDR, %ebx
|
||||
cmpl $LOAD_PHYSICAL_ADDR, %ebx
|
||||
jge 1f
|
||||
#endif
|
||||
movl $LOAD_PHYSICAL_ADDR, %ebx
|
||||
1:
|
||||
|
||||
/* Target address to relocate to for decompression */
|
||||
addl $z_extract_offset, %ebx
|
||||
@@ -191,14 +193,14 @@ relocated:
|
||||
leal boot_heap(%ebx), %eax
|
||||
pushl %eax /* heap area */
|
||||
pushl %esi /* real mode pointer */
|
||||
call decompress_kernel
|
||||
call decompress_kernel /* returns kernel location in %eax */
|
||||
addl $24, %esp
|
||||
|
||||
/*
|
||||
* Jump to the decompressed kernel.
|
||||
*/
|
||||
xorl %ebx, %ebx
|
||||
jmp *%ebp
|
||||
jmp *%eax
|
||||
|
||||
/*
|
||||
* Stack and heap for uncompression
|
||||
|
||||
@@ -94,9 +94,11 @@ ENTRY(startup_32)
|
||||
addl %eax, %ebx
|
||||
notl %eax
|
||||
andl %eax, %ebx
|
||||
#else
|
||||
movl $LOAD_PHYSICAL_ADDR, %ebx
|
||||
cmpl $LOAD_PHYSICAL_ADDR, %ebx
|
||||
jge 1f
|
||||
#endif
|
||||
movl $LOAD_PHYSICAL_ADDR, %ebx
|
||||
1:
|
||||
|
||||
/* Target address to relocate to for decompression */
|
||||
addl $z_extract_offset, %ebx
|
||||
@@ -269,9 +271,11 @@ preferred_addr:
|
||||
addq %rax, %rbp
|
||||
notq %rax
|
||||
andq %rax, %rbp
|
||||
#else
|
||||
movq $LOAD_PHYSICAL_ADDR, %rbp
|
||||
cmpq $LOAD_PHYSICAL_ADDR, %rbp
|
||||
jge 1f
|
||||
#endif
|
||||
movq $LOAD_PHYSICAL_ADDR, %rbp
|
||||
1:
|
||||
|
||||
/* Target address to relocate to for decompression */
|
||||
leaq z_extract_offset(%rbp), %rbx
|
||||
@@ -339,13 +343,13 @@ relocated:
|
||||
movl $z_input_len, %ecx /* input_len */
|
||||
movq %rbp, %r8 /* output target address */
|
||||
movq $z_output_len, %r9 /* decompressed length */
|
||||
call decompress_kernel
|
||||
call decompress_kernel /* returns kernel location in %rax */
|
||||
popq %rsi
|
||||
|
||||
/*
|
||||
* Jump to the decompressed kernel.
|
||||
*/
|
||||
jmp *%rbp
|
||||
jmp *%rax
|
||||
|
||||
.code32
|
||||
no_longmode:
|
||||
|
||||
@@ -112,14 +112,8 @@ struct boot_params *real_mode; /* Pointer to real-mode data */
|
||||
void *memset(void *s, int c, size_t n);
|
||||
void *memcpy(void *dest, const void *src, size_t n);
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
#define memptr long
|
||||
#else
|
||||
#define memptr unsigned
|
||||
#endif
|
||||
|
||||
static memptr free_mem_ptr;
|
||||
static memptr free_mem_end_ptr;
|
||||
memptr free_mem_ptr;
|
||||
memptr free_mem_end_ptr;
|
||||
|
||||
static char *vidmem;
|
||||
static int vidport;
|
||||
@@ -395,7 +389,7 @@ static void parse_elf(void *output)
|
||||
free(phdrs);
|
||||
}
|
||||
|
||||
asmlinkage void decompress_kernel(void *rmode, memptr heap,
|
||||
asmlinkage void *decompress_kernel(void *rmode, memptr heap,
|
||||
unsigned char *input_data,
|
||||
unsigned long input_len,
|
||||
unsigned char *output,
|
||||
@@ -422,6 +416,10 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
|
||||
free_mem_ptr = heap; /* Heap */
|
||||
free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
|
||||
|
||||
output = choose_kernel_location(input_data, input_len,
|
||||
output, output_len);
|
||||
|
||||
/* Validate memory location choices. */
|
||||
if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
|
||||
error("Destination address inappropriately aligned");
|
||||
#ifdef CONFIG_X86_64
|
||||
@@ -441,5 +439,5 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
|
||||
parse_elf(output);
|
||||
handle_relocations(output, output_len);
|
||||
debug_putstr("done.\nBooting the kernel.\n");
|
||||
return;
|
||||
return output;
|
||||
}
|
||||
|
||||
@@ -23,7 +23,15 @@
|
||||
#define BOOT_BOOT_H
|
||||
#include "../ctype.h"
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
#define memptr long
|
||||
#else
|
||||
#define memptr unsigned
|
||||
#endif
|
||||
|
||||
/* misc.c */
|
||||
extern memptr free_mem_ptr;
|
||||
extern memptr free_mem_end_ptr;
|
||||
extern struct boot_params *real_mode; /* Pointer to real-mode data */
|
||||
void __putstr(const char *s);
|
||||
#define error_putstr(__x) __putstr(__x)
|
||||
@@ -39,23 +47,40 @@ static inline void debug_putstr(const char *s)
|
||||
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_EARLY_PRINTK
|
||||
|
||||
#if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE
|
||||
/* cmdline.c */
|
||||
int cmdline_find_option(const char *option, char *buffer, int bufsize);
|
||||
int cmdline_find_option_bool(const char *option);
|
||||
#endif
|
||||
|
||||
|
||||
#if CONFIG_RANDOMIZE_BASE
|
||||
/* aslr.c */
|
||||
unsigned char *choose_kernel_location(unsigned char *input,
|
||||
unsigned long input_size,
|
||||
unsigned char *output,
|
||||
unsigned long output_size);
|
||||
/* cpuflags.c */
|
||||
bool has_cpuflag(int flag);
|
||||
#else
|
||||
static inline
|
||||
unsigned char *choose_kernel_location(unsigned char *input,
|
||||
unsigned long input_size,
|
||||
unsigned char *output,
|
||||
unsigned long output_size)
|
||||
{
|
||||
return output;
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_EARLY_PRINTK
|
||||
/* early_serial_console.c */
|
||||
extern int early_serial_base;
|
||||
void console_init(void);
|
||||
|
||||
#else
|
||||
|
||||
/* early_serial_console.c */
|
||||
static const int early_serial_base;
|
||||
static inline void console_init(void)
|
||||
{ }
|
||||
|
||||
#endif
|
||||
|
||||
#endif
|
||||
|
||||
@@ -28,8 +28,6 @@
|
||||
#include <asm/required-features.h>
|
||||
#include <asm/msr-index.h>
|
||||
|
||||
struct cpu_features cpu;
|
||||
static u32 cpu_vendor[3];
|
||||
static u32 err_flags[NCAPINTS];
|
||||
|
||||
static const int req_level = CONFIG_X86_MINIMUM_CPU_FAMILY;
|
||||
@@ -69,92 +67,8 @@ static int is_transmeta(void)
|
||||
cpu_vendor[2] == A32('M', 'x', '8', '6');
|
||||
}
|
||||
|
||||
static int has_fpu(void)
|
||||
{
|
||||
u16 fcw = -1, fsw = -1;
|
||||
u32 cr0;
|
||||
|
||||
asm("movl %%cr0,%0" : "=r" (cr0));
|
||||
if (cr0 & (X86_CR0_EM|X86_CR0_TS)) {
|
||||
cr0 &= ~(X86_CR0_EM|X86_CR0_TS);
|
||||
asm volatile("movl %0,%%cr0" : : "r" (cr0));
|
||||
}
|
||||
|
||||
asm volatile("fninit ; fnstsw %0 ; fnstcw %1"
|
||||
: "+m" (fsw), "+m" (fcw));
|
||||
|
||||
return fsw == 0 && (fcw & 0x103f) == 0x003f;
|
||||
}
|
||||
|
||||
static int has_eflag(u32 mask)
|
||||
{
|
||||
u32 f0, f1;
|
||||
|
||||
asm("pushfl ; "
|
||||
"pushfl ; "
|
||||
"popl %0 ; "
|
||||
"movl %0,%1 ; "
|
||||
"xorl %2,%1 ; "
|
||||
"pushl %1 ; "
|
||||
"popfl ; "
|
||||
"pushfl ; "
|
||||
"popl %1 ; "
|
||||
"popfl"
|
||||
: "=&r" (f0), "=&r" (f1)
|
||||
: "ri" (mask));
|
||||
|
||||
return !!((f0^f1) & mask);
|
||||
}
|
||||
|
||||
static void get_flags(void)
|
||||
{
|
||||
u32 max_intel_level, max_amd_level;
|
||||
u32 tfms;
|
||||
|
||||
if (has_fpu())
|
||||
set_bit(X86_FEATURE_FPU, cpu.flags);
|
||||
|
||||
if (has_eflag(X86_EFLAGS_ID)) {
|
||||
asm("cpuid"
|
||||
: "=a" (max_intel_level),
|
||||
"=b" (cpu_vendor[0]),
|
||||
"=d" (cpu_vendor[1]),
|
||||
"=c" (cpu_vendor[2])
|
||||
: "a" (0));
|
||||
|
||||
if (max_intel_level >= 0x00000001 &&
|
||||
max_intel_level <= 0x0000ffff) {
|
||||
asm("cpuid"
|
||||
: "=a" (tfms),
|
||||
"=c" (cpu.flags[4]),
|
||||
"=d" (cpu.flags[0])
|
||||
: "a" (0x00000001)
|
||||
: "ebx");
|
||||
cpu.level = (tfms >> 8) & 15;
|
||||
cpu.model = (tfms >> 4) & 15;
|
||||
if (cpu.level >= 6)
|
||||
cpu.model += ((tfms >> 16) & 0xf) << 4;
|
||||
}
|
||||
|
||||
asm("cpuid"
|
||||
: "=a" (max_amd_level)
|
||||
: "a" (0x80000000)
|
||||
: "ebx", "ecx", "edx");
|
||||
|
||||
if (max_amd_level >= 0x80000001 &&
|
||||
max_amd_level <= 0x8000ffff) {
|
||||
u32 eax = 0x80000001;
|
||||
asm("cpuid"
|
||||
: "+a" (eax),
|
||||
"=c" (cpu.flags[6]),
|
||||
"=d" (cpu.flags[1])
|
||||
: : "ebx");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Returns a bitmask of which words we have error bits in */
|
||||
static int check_flags(void)
|
||||
static int check_cpuflags(void)
|
||||
{
|
||||
u32 err;
|
||||
int i;
|
||||
@@ -187,8 +101,8 @@ int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr)
|
||||
if (has_eflag(X86_EFLAGS_AC))
|
||||
cpu.level = 4;
|
||||
|
||||
get_flags();
|
||||
err = check_flags();
|
||||
get_cpuflags();
|
||||
err = check_cpuflags();
|
||||
|
||||
if (test_bit(X86_FEATURE_LM, cpu.flags))
|
||||
cpu.level = 64;
|
||||
@@ -207,8 +121,8 @@ int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr)
|
||||
eax &= ~(1 << 15);
|
||||
asm("wrmsr" : : "a" (eax), "d" (edx), "c" (ecx));
|
||||
|
||||
get_flags(); /* Make sure it really did something */
|
||||
err = check_flags();
|
||||
get_cpuflags(); /* Make sure it really did something */
|
||||
err = check_cpuflags();
|
||||
} else if (err == 0x01 &&
|
||||
!(err_flags[0] & ~(1 << X86_FEATURE_CX8)) &&
|
||||
is_centaur() && cpu.model >= 6) {
|
||||
@@ -223,7 +137,7 @@ int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr)
|
||||
asm("wrmsr" : : "a" (eax), "d" (edx), "c" (ecx));
|
||||
|
||||
set_bit(X86_FEATURE_CX8, cpu.flags);
|
||||
err = check_flags();
|
||||
err = check_cpuflags();
|
||||
} else if (err == 0x01 && is_transmeta()) {
|
||||
/* Transmeta might have masked feature bits in word 0 */
|
||||
|
||||
@@ -238,7 +152,7 @@ int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr)
|
||||
: : "ecx", "ebx");
|
||||
asm("wrmsr" : : "a" (eax), "d" (edx), "c" (ecx));
|
||||
|
||||
err = check_flags();
|
||||
err = check_cpuflags();
|
||||
}
|
||||
|
||||
if (err_flags_ptr)
|
||||
|
||||
104
arch/x86/boot/cpuflags.c
Normal file
104
arch/x86/boot/cpuflags.c
Normal file
@@ -0,0 +1,104 @@
|
||||
#include <linux/types.h>
|
||||
#include "bitops.h"
|
||||
|
||||
#include <asm/processor-flags.h>
|
||||
#include <asm/required-features.h>
|
||||
#include <asm/msr-index.h>
|
||||
#include "cpuflags.h"
|
||||
|
||||
struct cpu_features cpu;
|
||||
u32 cpu_vendor[3];
|
||||
|
||||
static bool loaded_flags;
|
||||
|
||||
static int has_fpu(void)
|
||||
{
|
||||
u16 fcw = -1, fsw = -1;
|
||||
unsigned long cr0;
|
||||
|
||||
asm volatile("mov %%cr0,%0" : "=r" (cr0));
|
||||
if (cr0 & (X86_CR0_EM|X86_CR0_TS)) {
|
||||
cr0 &= ~(X86_CR0_EM|X86_CR0_TS);
|
||||
asm volatile("mov %0,%%cr0" : : "r" (cr0));
|
||||
}
|
||||
|
||||
asm volatile("fninit ; fnstsw %0 ; fnstcw %1"
|
||||
: "+m" (fsw), "+m" (fcw));
|
||||
|
||||
return fsw == 0 && (fcw & 0x103f) == 0x003f;
|
||||
}
|
||||
|
||||
int has_eflag(unsigned long mask)
|
||||
{
|
||||
unsigned long f0, f1;
|
||||
|
||||
asm volatile("pushf \n\t"
|
||||
"pushf \n\t"
|
||||
"pop %0 \n\t"
|
||||
"mov %0,%1 \n\t"
|
||||
"xor %2,%1 \n\t"
|
||||
"push %1 \n\t"
|
||||
"popf \n\t"
|
||||
"pushf \n\t"
|
||||
"pop %1 \n\t"
|
||||
"popf"
|
||||
: "=&r" (f0), "=&r" (f1)
|
||||
: "ri" (mask));
|
||||
|
||||
return !!((f0^f1) & mask);
|
||||
}
|
||||
|
||||
/* Handle x86_32 PIC using ebx. */
|
||||
#if defined(__i386__) && defined(__PIC__)
|
||||
# define EBX_REG "=r"
|
||||
#else
|
||||
# define EBX_REG "=b"
|
||||
#endif
|
||||
|
||||
static inline void cpuid(u32 id, u32 *a, u32 *b, u32 *c, u32 *d)
|
||||
{
|
||||
asm volatile(".ifnc %%ebx,%3 ; movl %%ebx,%3 ; .endif \n\t"
|
||||
"cpuid \n\t"
|
||||
".ifnc %%ebx,%3 ; xchgl %%ebx,%3 ; .endif \n\t"
|
||||
: "=a" (*a), "=c" (*c), "=d" (*d), EBX_REG (*b)
|
||||
: "a" (id)
|
||||
);
|
||||
}
|
||||
|
||||
void get_cpuflags(void)
|
||||
{
|
||||
u32 max_intel_level, max_amd_level;
|
||||
u32 tfms;
|
||||
u32 ignored;
|
||||
|
||||
if (loaded_flags)
|
||||
return;
|
||||
loaded_flags = true;
|
||||
|
||||
if (has_fpu())
|
||||
set_bit(X86_FEATURE_FPU, cpu.flags);
|
||||
|
||||
if (has_eflag(X86_EFLAGS_ID)) {
|
||||
cpuid(0x0, &max_intel_level, &cpu_vendor[0], &cpu_vendor[2],
|
||||
&cpu_vendor[1]);
|
||||
|
||||
if (max_intel_level >= 0x00000001 &&
|
||||
max_intel_level <= 0x0000ffff) {
|
||||
cpuid(0x1, &tfms, &ignored, &cpu.flags[4],
|
||||
&cpu.flags[0]);
|
||||
cpu.level = (tfms >> 8) & 15;
|
||||
cpu.model = (tfms >> 4) & 15;
|
||||
if (cpu.level >= 6)
|
||||
cpu.model += ((tfms >> 16) & 0xf) << 4;
|
||||
}
|
||||
|
||||
cpuid(0x80000000, &max_amd_level, &ignored, &ignored,
|
||||
&ignored);
|
||||
|
||||
if (max_amd_level >= 0x80000001 &&
|
||||
max_amd_level <= 0x8000ffff) {
|
||||
cpuid(0x80000001, &ignored, &ignored, &cpu.flags[6],
|
||||
&cpu.flags[1]);
|
||||
}
|
||||
}
|
||||
}
|
||||
19
arch/x86/boot/cpuflags.h
Normal file
19
arch/x86/boot/cpuflags.h
Normal file
@@ -0,0 +1,19 @@
|
||||
#ifndef BOOT_CPUFLAGS_H
|
||||
#define BOOT_CPUFLAGS_H
|
||||
|
||||
#include <asm/cpufeature.h>
|
||||
#include <asm/processor-flags.h>
|
||||
|
||||
struct cpu_features {
|
||||
int level; /* Family, or 64 for x86-64 */
|
||||
int model;
|
||||
u32 flags[NCAPINTS];
|
||||
};
|
||||
|
||||
extern struct cpu_features cpu;
|
||||
extern u32 cpu_vendor[3];
|
||||
|
||||
int has_eflag(unsigned long mask);
|
||||
void get_cpuflags(void);
|
||||
|
||||
#endif
|
||||
Reference in New Issue
Block a user