diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/boot/compressed/eboot.c | 2 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 147 |
2 files changed, 121 insertions, 28 deletions
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index c3e869eaef0c..e007887a33b0 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -767,7 +767,7 @@ static efi_status_t setup_e820(struct boot_params *params, m |= (u64)efi->efi_memmap_hi << 32; #endif - d = (efi_memory_desc_t *)(m + (i * efi->efi_memdesc_size)); + d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); switch (d->type) { case EFI_RESERVED_TYPE: case EFI_RUNTIME_SERVICES_CODE: diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 91f27ab970ef..17818ba6906f 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -37,7 +37,9 @@ #include <linux/uts.h> #include <linux/utsname.h> #include <linux/ctype.h> +#include <linux/efi.h> #include <generated/utsrelease.h> +#include <asm/efi.h> /* Macros used by the included decompressor code below. */ #define STATIC @@ -479,35 +481,31 @@ static unsigned long slots_fetch_random(void) return 0; } -static void process_e820_entry(struct boot_e820_entry *entry, +static void process_mem_region(struct mem_vector *entry, unsigned long minimum, unsigned long image_size) { struct mem_vector region, overlap; struct slot_area slot_area; unsigned long start_orig, end; - struct boot_e820_entry cur_entry; - - /* Skip non-RAM entries. */ - if (entry->type != E820_TYPE_RAM) - return; + struct mem_vector cur_entry; /* On 32-bit, ignore entries entirely above our maximum. */ - if (IS_ENABLED(CONFIG_X86_32) && entry->addr >= KERNEL_IMAGE_SIZE) + if (IS_ENABLED(CONFIG_X86_32) && entry->start >= KERNEL_IMAGE_SIZE) return; /* Ignore entries entirely below our minimum. */ - if (entry->addr + entry->size < minimum) + if (entry->start + entry->size < minimum) return; /* Ignore entries above memory limit */ - end = min(entry->size + entry->addr, mem_limit); - if (entry->addr >= end) + end = min(entry->size + entry->start, mem_limit); + if (entry->start >= end) return; - cur_entry.addr = entry->addr; - cur_entry.size = end - entry->addr; + cur_entry.start = entry->start; + cur_entry.size = end - entry->start; - region.start = cur_entry.addr; + region.start = cur_entry.start; region.size = cur_entry.size; /* Give up if slot area array is full. */ @@ -521,8 +519,8 @@ static void process_e820_entry(struct boot_e820_entry *entry, /* Potentially raise address to meet alignment needs. */ region.start = ALIGN(region.start, CONFIG_PHYSICAL_ALIGN); - /* Did we raise the address above this e820 region? */ - if (region.start > cur_entry.addr + cur_entry.size) + /* Did we raise the address above the passed in memory entry? */ + if (region.start > cur_entry.start + cur_entry.size) return; /* Reduce size by any delta from the original address. */ @@ -562,31 +560,126 @@ static void process_e820_entry(struct boot_e820_entry *entry, } } -static unsigned long find_random_phys_addr(unsigned long minimum, - unsigned long image_size) +#ifdef CONFIG_EFI +/* + * Returns true if mirror region found (and must have been processed + * for slots adding) + */ +static bool +process_efi_entries(unsigned long minimum, unsigned long image_size) { + struct efi_info *e = &boot_params->efi_info; + bool efi_mirror_found = false; + struct mem_vector region; + efi_memory_desc_t *md; + unsigned long pmap; + char *signature; + u32 nr_desc; int i; - unsigned long addr; - /* Check if we had too many memmaps. */ - if (memmap_too_large) { - debug_putstr("Aborted e820 scan (more than 4 memmap= args)!\n"); - return 0; + signature = (char *)&e->efi_loader_signature; + if (strncmp(signature, EFI32_LOADER_SIGNATURE, 4) && + strncmp(signature, EFI64_LOADER_SIGNATURE, 4)) + return false; + +#ifdef CONFIG_X86_32 + /* Can't handle data above 4GB at this time */ + if (e->efi_memmap_hi) { + warn("EFI memmap is above 4GB, can't be handled now on x86_32. EFI should be disabled.\n"); + return false; } + pmap = e->efi_memmap; +#else + pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32)); +#endif - /* Make sure minimum is aligned. */ - minimum = ALIGN(minimum, CONFIG_PHYSICAL_ALIGN); + nr_desc = e->efi_memmap_size / e->efi_memdesc_size; + for (i = 0; i < nr_desc; i++) { + md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i); + if (md->attribute & EFI_MEMORY_MORE_RELIABLE) { + efi_mirror_found = true; + break; + } + } + + for (i = 0; i < nr_desc; i++) { + md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i); + + /* + * Here we are more conservative in picking free memory than + * the EFI spec allows: + * + * According to the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also + * free memory and thus available to place the kernel image into, + * but in practice there's firmware where using that memory leads + * to crashes. + * + * Only EFI_CONVENTIONAL_MEMORY is guaranteed to be free. + */ + if (md->type != EFI_CONVENTIONAL_MEMORY) + continue; + + if (efi_mirror_found && + !(md->attribute & EFI_MEMORY_MORE_RELIABLE)) + continue; + + region.start = md->phys_addr; + region.size = md->num_pages << EFI_PAGE_SHIFT; + process_mem_region(®ion, minimum, image_size); + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted EFI scan (slot_areas full)!\n"); + break; + } + } + return true; +} +#else +static inline bool +process_efi_entries(unsigned long minimum, unsigned long image_size) +{ + return false; +} +#endif + +static void process_e820_entries(unsigned long minimum, + unsigned long image_size) +{ + int i; + struct mem_vector region; + struct boot_e820_entry *entry; /* Verify potential e820 positions, appending to slots list. */ for (i = 0; i < boot_params->e820_entries; i++) { - process_e820_entry(&boot_params->e820_table[i], minimum, - image_size); + entry = &boot_params->e820_table[i]; + /* Skip non-RAM entries. */ + if (entry->type != E820_TYPE_RAM) + continue; + region.start = entry->addr; + region.size = entry->size; + process_mem_region(®ion, minimum, image_size); if (slot_area_index == MAX_SLOT_AREA) { debug_putstr("Aborted e820 scan (slot_areas full)!\n"); break; } } +} + +static unsigned long find_random_phys_addr(unsigned long minimum, + unsigned long image_size) +{ + /* Check if we had too many memmaps. */ + if (memmap_too_large) { + debug_putstr("Aborted memory entries scan (more than 4 memmap= args)!\n"); + return 0; + } + + /* Make sure minimum is aligned. */ + minimum = ALIGN(minimum, CONFIG_PHYSICAL_ALIGN); + + if (process_efi_entries(minimum, image_size)) + return slots_fetch_random(); + process_e820_entries(minimum, image_size); return slots_fetch_random(); } @@ -645,7 +738,7 @@ void choose_random_location(unsigned long input, */ min_addr = min(*output, 512UL << 20); - /* Walk e820 and find a random address. */ + /* Walk available memory entries to find a random address. */ random_addr = find_random_phys_addr(min_addr, output_size); if (!random_addr) { warn("Physical KASLR disabled: no suitable memory region!"); |