From abfb7b686a3e5be27bf81db62f9c5c895b76f5d1 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 24 Dec 2016 13:59:23 +0000 Subject: [PATCH 1/3] efi/libstub/arm*: Pass latest memory map to the kernel As reported by James Morse, the current libstub code involving the annotated memory map only works somewhat correctly by accident, due to the fact that a pool allocation happens to be reused immediately, retaining its former contents on most implementations of the UEFI boot services. Instead of juggling memory maps, which makes the code more complex than it needs to be, simply put placeholder values into the FDT for the memory map parameters, and only write the actual values after ExitBootServices() has been called. Reported-by: James Morse Signed-off-by: Ard Biesheuvel Cc: Cc: Jeffrey Hugo Cc: Linus Torvalds Cc: Matt Fleming Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org Fixes: ed9cc156c42f ("efi/libstub: Use efi_exit_boot_services() in FDT") Link: http://lkml.kernel.org/r/1482587963-20183-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar --- drivers/firmware/efi/libstub/efistub.h | 8 --- drivers/firmware/efi/libstub/fdt.c | 87 +++++++++++++++++--------- 2 files changed, 56 insertions(+), 39 deletions(-) diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index b98824e3800a..0e2a96b12cb3 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -39,14 +39,6 @@ efi_status_t efi_file_close(void *handle); unsigned long get_dram_base(efi_system_table_t *sys_table_arg); -efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, - unsigned long orig_fdt_size, - void *fdt, int new_fdt_size, char *cmdline_ptr, - u64 initrd_addr, u64 initrd_size, - efi_memory_desc_t *memory_map, - unsigned long map_size, unsigned long desc_size, - u32 desc_ver); - efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, void *handle, unsigned long *new_fdt_addr, diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index a6a93116a8f0..921dfa047202 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -16,13 +16,10 @@ #include "efistub.h" -efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, - unsigned long orig_fdt_size, - void *fdt, int new_fdt_size, char *cmdline_ptr, - u64 initrd_addr, u64 initrd_size, - efi_memory_desc_t *memory_map, - unsigned long map_size, unsigned long desc_size, - u32 desc_ver) +static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, + unsigned long orig_fdt_size, + void *fdt, int new_fdt_size, char *cmdline_ptr, + u64 initrd_addr, u64 initrd_size) { int node, num_rsv; int status; @@ -101,25 +98,23 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, if (status) goto fdt_set_fail; - fdt_val64 = cpu_to_fdt64((u64)(unsigned long)memory_map); + fdt_val64 = U64_MAX; /* placeholder */ status = fdt_setprop(fdt, node, "linux,uefi-mmap-start", &fdt_val64, sizeof(fdt_val64)); if (status) goto fdt_set_fail; - fdt_val32 = cpu_to_fdt32(map_size); + fdt_val32 = U32_MAX; /* placeholder */ status = fdt_setprop(fdt, node, "linux,uefi-mmap-size", &fdt_val32, sizeof(fdt_val32)); if (status) goto fdt_set_fail; - fdt_val32 = cpu_to_fdt32(desc_size); status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size", &fdt_val32, sizeof(fdt_val32)); if (status) goto fdt_set_fail; - fdt_val32 = cpu_to_fdt32(desc_ver); status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver", &fdt_val32, sizeof(fdt_val32)); if (status) @@ -148,6 +143,43 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, return EFI_LOAD_ERROR; } +static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) +{ + int node = fdt_path_offset(fdt, "/chosen"); + u64 fdt_val64; + u32 fdt_val32; + int err; + + if (node < 0) + return EFI_LOAD_ERROR; + + fdt_val64 = cpu_to_fdt64((unsigned long)*map->map); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-start", + &fdt_val64, sizeof(fdt_val64)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->map_size); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-size", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->desc_size); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-desc-size", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->desc_ver); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-desc-ver", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + return EFI_SUCCESS; +} + #ifndef EFI_FDT_ALIGN #define EFI_FDT_ALIGN EFI_PAGE_SIZE #endif @@ -243,20 +275,10 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, goto fail; } - /* - * Now that we have done our final memory allocation (and free) - * we can get the memory map key needed for - * exit_boot_services(). - */ - status = efi_get_memory_map(sys_table, &map); - if (status != EFI_SUCCESS) - goto fail_free_new_fdt; - status = update_fdt(sys_table, (void *)fdt_addr, fdt_size, (void *)*new_fdt_addr, new_fdt_size, - cmdline_ptr, initrd_addr, initrd_size, - memory_map, map_size, desc_size, desc_ver); + cmdline_ptr, initrd_addr, initrd_size); /* Succeeding the first time is the expected case. */ if (status == EFI_SUCCESS) @@ -266,20 +288,16 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, /* * We need to allocate more space for the new * device tree, so free existing buffer that is - * too small. Also free memory map, as we will need - * to get new one that reflects the free/alloc we do - * on the device tree buffer. + * too small. */ efi_free(sys_table, new_fdt_size, *new_fdt_addr); - sys_table->boottime->free_pool(memory_map); new_fdt_size += EFI_PAGE_SIZE; } else { pr_efi_err(sys_table, "Unable to construct new device tree.\n"); - goto fail_free_mmap; + goto fail_free_new_fdt; } } - sys_table->boottime->free_pool(memory_map); priv.runtime_map = runtime_map; priv.runtime_entry_count = &runtime_entry_count; status = efi_exit_boot_services(sys_table, handle, &map, &priv, @@ -288,6 +306,16 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, if (status == EFI_SUCCESS) { efi_set_virtual_address_map_t *svam; + status = update_fdt_memmap((void *)*new_fdt_addr, &map); + if (status != EFI_SUCCESS) { + /* + * The kernel won't get far without the memory map, but + * may still be able to print something meaningful so + * return success here. + */ + return EFI_SUCCESS; + } + /* Install the new virtual address map */ svam = sys_table->runtime->set_virtual_address_map; status = svam(runtime_entry_count * desc_size, desc_size, @@ -319,9 +347,6 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, pr_efi_err(sys_table, "Exit boot services failed.\n"); -fail_free_mmap: - sys_table->boottime->free_pool(memory_map); - fail_free_new_fdt: efi_free(sys_table, new_fdt_size, *new_fdt_addr); From 20b1e22d01a4b0b11d3a1066e9feb04be38607ec Mon Sep 17 00:00:00 2001 From: Nicolai Stange Date: Thu, 5 Jan 2017 13:51:29 +0100 Subject: [PATCH 2/3] x86/efi: Don't allocate memmap through memblock after mm_init() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With the following commit: 4bc9f92e64c8 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") ... efi_bgrt_init() calls into the memblock allocator through efi_mem_reserve() => efi_arch_mem_reserve() *after* mm_init() has been called. Indeed, KASAN reports a bad read access later on in efi_free_boot_services(): BUG: KASAN: use-after-free in efi_free_boot_services+0xae/0x24c at addr ffff88022de12740 Read of size 4 by task swapper/0/0 page:ffffea0008b78480 count:0 mapcount:-127 mapping: (null) index:0x1 flags: 0x5fff8000000000() [...] Call Trace: dump_stack+0x68/0x9f kasan_report_error+0x4c8/0x500 kasan_report+0x58/0x60 __asan_load4+0x61/0x80 efi_free_boot_services+0xae/0x24c start_kernel+0x527/0x562 x86_64_start_reservations+0x24/0x26 x86_64_start_kernel+0x157/0x17a start_cpu+0x5/0x14 The instruction at the given address is the first read from the memmap's memory, i.e. the read of md->type in efi_free_boot_services(). Note that the writes earlier in efi_arch_mem_reserve() don't splat because they're done through early_memremap()ed addresses. So, after memblock is gone, allocations should be done through the "normal" page allocator. Introduce a helper, efi_memmap_alloc() for this. Use it from efi_arch_mem_reserve(), efi_free_boot_services() and, for the sake of consistency, from efi_fake_memmap() as well. Note that for the latter, the memmap allocations cease to be page aligned. This isn't needed though. Tested-by: Dan Williams Signed-off-by: Nicolai Stange Reviewed-by: Ard Biesheuvel Cc: # v4.9 Cc: Dave Young Cc: Linus Torvalds Cc: Matt Fleming Cc: Mika Penttilä Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Fixes: 4bc9f92e64c8 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") Link: http://lkml.kernel.org/r/20170105125130.2815-1-nicstange@gmail.com Signed-off-by: Ingo Molnar --- arch/x86/platform/efi/quirks.c | 4 ++-- drivers/firmware/efi/fake_mem.c | 3 +-- drivers/firmware/efi/memmap.c | 38 +++++++++++++++++++++++++++++++++ include/linux/efi.h | 1 + 4 files changed, 42 insertions(+), 4 deletions(-) diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index 10aca63a50d7..30031d5293c4 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -214,7 +214,7 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size) new_size = efi.memmap.desc_size * num_entries; - new_phys = memblock_alloc(new_size, 0); + new_phys = efi_memmap_alloc(num_entries); if (!new_phys) { pr_err("Could not allocate boot services memmap\n"); return; @@ -355,7 +355,7 @@ void __init efi_free_boot_services(void) } new_size = efi.memmap.desc_size * num_entries; - new_phys = memblock_alloc(new_size, 0); + new_phys = efi_memmap_alloc(num_entries); if (!new_phys) { pr_err("Failed to allocate new EFI memmap\n"); return; diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c index 520a40e5e0e4..6c7d60c239b5 100644 --- a/drivers/firmware/efi/fake_mem.c +++ b/drivers/firmware/efi/fake_mem.c @@ -71,8 +71,7 @@ void __init efi_fake_memmap(void) } /* allocate memory for new EFI memmap */ - new_memmap_phy = memblock_alloc(efi.memmap.desc_size * new_nr_map, - PAGE_SIZE); + new_memmap_phy = efi_memmap_alloc(new_nr_map); if (!new_memmap_phy) return; diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c index f03ddecd232b..78686443cb37 100644 --- a/drivers/firmware/efi/memmap.c +++ b/drivers/firmware/efi/memmap.c @@ -9,6 +9,44 @@ #include #include #include +#include +#include + +static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size) +{ + return memblock_alloc(size, 0); +} + +static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size) +{ + unsigned int order = get_order(size); + struct page *p = alloc_pages(GFP_KERNEL, order); + + if (!p) + return 0; + + return PFN_PHYS(page_to_pfn(p)); +} + +/** + * efi_memmap_alloc - Allocate memory for the EFI memory map + * @num_entries: Number of entries in the allocated map. + * + * Depending on whether mm_init() has already been invoked or not, + * either memblock or "normal" page allocation is used. + * + * Returns the physical address of the allocated memory map on + * success, zero on failure. + */ +phys_addr_t __init efi_memmap_alloc(unsigned int num_entries) +{ + unsigned long size = num_entries * efi.memmap.desc_size; + + if (slab_is_available()) + return __efi_memmap_alloc_late(size); + + return __efi_memmap_alloc_early(size); +} /** * __efi_memmap_init - Common code for mapping the EFI memory map diff --git a/include/linux/efi.h b/include/linux/efi.h index a07a476178cd..0c5420208c40 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -950,6 +950,7 @@ static inline efi_status_t efi_query_variable_store(u32 attributes, #endif extern void __iomem *efi_lookup_mapped_addr(u64 phys_addr); +extern phys_addr_t __init efi_memmap_alloc(unsigned int num_entries); extern int __init efi_memmap_init_early(struct efi_memory_map_data *data); extern int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size); extern void __init efi_memmap_unmap(void); From 0100a3e67a9cef64d72cd3a1da86f3ddbee50363 Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Mon, 12 Dec 2016 18:42:28 -0500 Subject: [PATCH 3/3] efi/x86: Prune invalid memory map entries and fix boot regression Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW (2.28), include memory map entries with phys_addr=0x0 and num_pages=0. These machines fail to boot after the following commit, commit 8e80632fb23f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()") Fix this by removing such bogus entries from the memory map. Furthermore, currently the log output for this case (with efi=debug) looks like: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[0x0000000000000000-0xffffffffffffffff] (0MB) This is clearly wrong, and also not as informative as it could be. This patch changes it so that if we find obviously invalid memory map entries, we print an error and skip those entries. It also detects the display of the address range calculation overflow, so the new output is: [ 0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[0x0000000000000000-0x0000000000000000] (invalid) It also detects memory map sizes that would overflow the physical address, for example phys_addr=0xfffffffffffff000 and num_pages=0x0200000000000001, and prints: [ 0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[phys_addr=0xfffffffffffff000-0x20ffffffffffffffff] (invalid) It then removes these entries from the memory map. Signed-off-by: Peter Jones Signed-off-by: Ard Biesheuvel [ardb: refactor for clarity with no functional changes, avoid PAGE_SHIFT] Signed-off-by: Matt Fleming [Matt: Include bugzilla info in commit log] Cc: # v4.9+ Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://bugzilla.kernel.org/show_bug.cgi?id=191121 Signed-off-by: Ingo Molnar --- arch/x86/platform/efi/efi.c | 66 +++++++++++++++++++++++++++++++++++++ include/linux/efi.h | 1 + 2 files changed, 67 insertions(+) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 936a488d6cf6..274dfc481849 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -210,6 +210,70 @@ int __init efi_memblock_x86_reserve_range(void) return 0; } +#define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT) +#define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT) +#define U64_HIGH_BIT (~(U64_MAX >> 1)) + +static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i) +{ + u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1; + u64 end_hi = 0; + char buf[64]; + + if (md->num_pages == 0) { + end = 0; + } else if (md->num_pages > EFI_PAGES_MAX || + EFI_PAGES_MAX - md->num_pages < + (md->phys_addr >> EFI_PAGE_SHIFT)) { + end_hi = (md->num_pages & OVERFLOW_ADDR_MASK) + >> OVERFLOW_ADDR_SHIFT; + + if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT)) + end_hi += 1; + } else { + return true; + } + + pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n"); + + if (end_hi) { + pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n", + i, efi_md_typeattr_format(buf, sizeof(buf), md), + md->phys_addr, end_hi, end); + } else { + pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n", + i, efi_md_typeattr_format(buf, sizeof(buf), md), + md->phys_addr, end); + } + return false; +} + +static void __init efi_clean_memmap(void) +{ + efi_memory_desc_t *out = efi.memmap.map; + const efi_memory_desc_t *in = out; + const efi_memory_desc_t *end = efi.memmap.map_end; + int i, n_removal; + + for (i = n_removal = 0; in < end; i++) { + if (efi_memmap_entry_valid(in, i)) { + if (out != in) + memcpy(out, in, efi.memmap.desc_size); + out = (void *)out + efi.memmap.desc_size; + } else { + n_removal++; + } + in = (void *)in + efi.memmap.desc_size; + } + + if (n_removal > 0) { + u64 size = efi.memmap.nr_map - n_removal; + + pr_warn("Removing %d invalid memory map entries.\n", n_removal); + efi_memmap_install(efi.memmap.phys_map, size); + } +} + void __init efi_print_memmap(void) { efi_memory_desc_t *md; @@ -472,6 +536,8 @@ void __init efi_init(void) } } + efi_clean_memmap(); + if (efi_enabled(EFI_DBG)) efi_print_memmap(); } diff --git a/include/linux/efi.h b/include/linux/efi.h index 0c5420208c40..5b1af30ece55 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -103,6 +103,7 @@ typedef struct { #define EFI_PAGE_SHIFT 12 #define EFI_PAGE_SIZE (1UL << EFI_PAGE_SHIFT) +#define EFI_PAGES_MAX (U64_MAX >> EFI_PAGE_SHIFT) typedef struct { u32 type;