diff options
author | Linus Torvalds | 2019-11-26 09:48:19 -0800 |
---|---|---|
committer | Linus Torvalds | 2019-11-26 09:48:19 -0800 |
commit | 24ee25a6da84d83a25d93af52b5fef7407030b20 (patch) | |
tree | 7ffb1f27b7d38134fa2723ef695b59a452a6a17c /arch | |
parent | 64d6a12094f35d644540c15440874723b1887f9d (diff) | |
parent | 9eff303725da6530b615e9258f696149baa51df6 (diff) |
Merge branch 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 kdump updates from Ingo Molnar:
"This solves a kdump artifact where encrypted memory contents are
dumped, instead of unencrypted ones.
The solution also happens to simplify the kdump code, to everyone's
delight"
* 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/crash: Align function arguments on opening braces
x86/kdump: Remove the backup region handling
x86/kdump: Always reserve the low 1M when the crashkernel option is specified
x86/crash: Add a forward declaration of struct kimage
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/include/asm/crash.h | 8 | ||||
-rw-r--r-- | arch/x86/include/asm/kexec.h | 10 | ||||
-rw-r--r-- | arch/x86/include/asm/purgatory.h | 10 | ||||
-rw-r--r-- | arch/x86/kernel/crash.c | 128 | ||||
-rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 47 | ||||
-rw-r--r-- | arch/x86/purgatory/purgatory.c | 19 | ||||
-rw-r--r-- | arch/x86/realmode/init.c | 2 |
7 files changed, 46 insertions, 178 deletions
diff --git a/arch/x86/include/asm/crash.h b/arch/x86/include/asm/crash.h index 089b2850f9d1..f58de66091e5 100644 --- a/arch/x86/include/asm/crash.h +++ b/arch/x86/include/asm/crash.h @@ -2,9 +2,17 @@ #ifndef _ASM_X86_CRASH_H #define _ASM_X86_CRASH_H +struct kimage; + int crash_load_segments(struct kimage *image); int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params); void crash_smp_send_stop(void); +#ifdef CONFIG_KEXEC_CORE +void __init crash_reserve_low_1M(void); +#else +static inline void __init crash_reserve_low_1M(void) { } +#endif + #endif /* _ASM_X86_CRASH_H */ diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index 5e7d6b46de97..6802c59e8252 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -66,10 +66,6 @@ struct kimage; # define KEXEC_ARCH KEXEC_ARCH_X86_64 #endif -/* Memory to backup during crash kdump */ -#define KEXEC_BACKUP_SRC_START (0UL) -#define KEXEC_BACKUP_SRC_END (640 * 1024UL - 1) /* 640K */ - /* * This function is responsible for capturing register states if coming * via panic otherwise just fix up the ss and sp if coming via kernel @@ -154,12 +150,6 @@ struct kimage_arch { pud_t *pud; pmd_t *pmd; pte_t *pte; - /* Details of backup region */ - unsigned long backup_src_start; - unsigned long backup_src_sz; - - /* Physical address of backup segment */ - unsigned long backup_load_addr; /* Core ELF header buffer */ void *elf_headers; diff --git a/arch/x86/include/asm/purgatory.h b/arch/x86/include/asm/purgatory.h index 92c34e517da1..5528e9325049 100644 --- a/arch/x86/include/asm/purgatory.h +++ b/arch/x86/include/asm/purgatory.h @@ -6,16 +6,6 @@ #include <linux/purgatory.h> extern void purgatory(void); -/* - * These forward declarations serve two purposes: - * - * 1) Make sparse happy when checking arch/purgatory - * 2) Document that these are required to be global so the symbol - * lookup in kexec works - */ -extern unsigned long purgatory_backup_dest; -extern unsigned long purgatory_backup_src; -extern unsigned long purgatory_backup_sz; #endif /* __ASSEMBLY__ */ #endif /* _ASM_PURGATORY_H */ diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index eb651fbde92a..00fc55ac7ffa 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -24,6 +24,7 @@ #include <linux/export.h> #include <linux/slab.h> #include <linux/vmalloc.h> +#include <linux/memblock.h> #include <asm/processor.h> #include <asm/hardirq.h> @@ -39,6 +40,7 @@ #include <asm/virtext.h> #include <asm/intel_pt.h> #include <asm/crash.h> +#include <asm/cmdline.h> /* Used while preparing memory map entries for second kernel */ struct crash_memmap_data { @@ -68,6 +70,19 @@ static inline void cpu_crash_vmclear_loaded_vmcss(void) rcu_read_unlock(); } +/* + * When the crashkernel option is specified, only use the low + * 1M for the real mode trampoline. + */ +void __init crash_reserve_low_1M(void) +{ + if (cmdline_find_option(boot_command_line, "crashkernel", NULL, 0) < 0) + return; + + memblock_reserve(0, 1<<20); + pr_info("Reserving the low 1M of memory for crashkernel\n"); +} + #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) static void kdump_nmi_callback(int cpu, struct pt_regs *regs) @@ -173,8 +188,6 @@ void native_machine_crash_shutdown(struct pt_regs *regs) #ifdef CONFIG_KEXEC_FILE -static unsigned long crash_zero_bytes; - static int get_nr_ram_ranges_callback(struct resource *res, void *arg) { unsigned int *nr_ranges = arg; @@ -189,8 +202,7 @@ static struct crash_mem *fill_up_crash_elf_data(void) unsigned int nr_ranges = 0; struct crash_mem *cmem; - walk_system_ram_res(0, -1, &nr_ranges, - get_nr_ram_ranges_callback); + walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); if (!nr_ranges) return NULL; @@ -217,15 +229,19 @@ static int elf_header_exclude_ranges(struct crash_mem *cmem) { int ret = 0; + /* Exclude the low 1M because it is always reserved */ + ret = crash_exclude_mem_range(cmem, 0, 1<<20); + if (ret) + return ret; + /* Exclude crashkernel region */ ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); if (ret) return ret; - if (crashk_low_res.end) { + if (crashk_low_res.end) ret = crash_exclude_mem_range(cmem, crashk_low_res.start, - crashk_low_res.end); - } + crashk_low_res.end); return ret; } @@ -246,16 +262,13 @@ static int prepare_elf_headers(struct kimage *image, void **addr, unsigned long *sz) { struct crash_mem *cmem; - Elf64_Ehdr *ehdr; - Elf64_Phdr *phdr; - int ret, i; + int ret; cmem = fill_up_crash_elf_data(); if (!cmem) return -ENOMEM; - ret = walk_system_ram_res(0, -1, cmem, - prepare_elf64_ram_headers_callback); + ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback); if (ret) goto out; @@ -265,24 +278,8 @@ static int prepare_elf_headers(struct kimage *image, void **addr, goto out; /* By default prepare 64bit headers */ - ret = crash_prepare_elf64_headers(cmem, - IS_ENABLED(CONFIG_X86_64), addr, sz); - if (ret) - goto out; + ret = crash_prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz); - /* - * If a range matches backup region, adjust offset to backup - * segment. - */ - ehdr = (Elf64_Ehdr *)*addr; - phdr = (Elf64_Phdr *)(ehdr + 1); - for (i = 0; i < ehdr->e_phnum; phdr++, i++) - if (phdr->p_type == PT_LOAD && - phdr->p_paddr == image->arch.backup_src_start && - phdr->p_memsz == image->arch.backup_src_sz) { - phdr->p_offset = image->arch.backup_load_addr; - break; - } out: vfree(cmem); return ret; @@ -296,8 +293,7 @@ static int add_e820_entry(struct boot_params *params, struct e820_entry *entry) if (nr_e820_entries >= E820_MAX_ENTRIES_ZEROPAGE) return 1; - memcpy(¶ms->e820_table[nr_e820_entries], entry, - sizeof(struct e820_entry)); + memcpy(¶ms->e820_table[nr_e820_entries], entry, sizeof(struct e820_entry)); params->e820_entries++; return 0; } @@ -321,19 +317,11 @@ static int memmap_exclude_ranges(struct kimage *image, struct crash_mem *cmem, unsigned long long mend) { unsigned long start, end; - int ret = 0; cmem->ranges[0].start = mstart; cmem->ranges[0].end = mend; cmem->nr_ranges = 1; - /* Exclude Backup region */ - start = image->arch.backup_load_addr; - end = start + image->arch.backup_src_sz - 1; - ret = crash_exclude_mem_range(cmem, start, end); - if (ret) - return ret; - /* Exclude elf header region */ start = image->arch.elf_load_addr; end = start + image->arch.elf_headers_sz - 1; @@ -356,28 +344,28 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params) memset(&cmd, 0, sizeof(struct crash_memmap_data)); cmd.params = params; - /* Add first 640K segment */ - ei.addr = image->arch.backup_src_start; - ei.size = image->arch.backup_src_sz; - ei.type = E820_TYPE_RAM; - add_e820_entry(params, &ei); + /* Add the low 1M */ + cmd.type = E820_TYPE_RAM; + flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + walk_iomem_res_desc(IORES_DESC_NONE, flags, 0, (1<<20)-1, &cmd, + memmap_entry_callback); /* Add ACPI tables */ cmd.type = E820_TYPE_ACPI; flags = IORESOURCE_MEM | IORESOURCE_BUSY; walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1, &cmd, - memmap_entry_callback); + memmap_entry_callback); /* Add ACPI Non-volatile Storage */ cmd.type = E820_TYPE_NVS; walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1, &cmd, - memmap_entry_callback); + memmap_entry_callback); /* Add e820 reserved ranges */ cmd.type = E820_TYPE_RESERVED; flags = IORESOURCE_MEM; walk_iomem_res_desc(IORES_DESC_RESERVED, flags, 0, -1, &cmd, - memmap_entry_callback); + memmap_entry_callback); /* Add crashk_low_res region */ if (crashk_low_res.end) { @@ -388,8 +376,7 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params) } /* Exclude some ranges from crashk_res and add rest to memmap */ - ret = memmap_exclude_ranges(image, cmem, crashk_res.start, - crashk_res.end); + ret = memmap_exclude_ranges(image, cmem, crashk_res.start, crashk_res.end); if (ret) goto out; @@ -409,55 +396,12 @@ out: return ret; } -static int determine_backup_region(struct resource *res, void *arg) -{ - struct kimage *image = arg; - - image->arch.backup_src_start = res->start; - image->arch.backup_src_sz = resource_size(res); - - /* Expecting only one range for backup region */ - return 1; -} - int crash_load_segments(struct kimage *image) { int ret; struct kexec_buf kbuf = { .image = image, .buf_min = 0, .buf_max = ULONG_MAX, .top_down = false }; - /* - * Determine and load a segment for backup area. First 640K RAM - * region is backup source - */ - - ret = walk_system_ram_res(KEXEC_BACKUP_SRC_START, KEXEC_BACKUP_SRC_END, - image, determine_backup_region); - - /* Zero or postive return values are ok */ - if (ret < 0) - return ret; - - /* Add backup segment. */ - if (image->arch.backup_src_sz) { - kbuf.buffer = &crash_zero_bytes; - kbuf.bufsz = sizeof(crash_zero_bytes); - kbuf.memsz = image->arch.backup_src_sz; - kbuf.buf_align = PAGE_SIZE; - /* - * Ideally there is no source for backup segment. This is - * copied in purgatory after crash. Just add a zero filled - * segment for now to make sure checksum logic works fine. - */ - ret = kexec_add_buffer(&kbuf); - if (ret) - return ret; - image->arch.backup_load_addr = kbuf.mem; - pr_debug("Loaded backup region at 0x%lx backup_start=0x%lx memsz=0x%lx\n", - image->arch.backup_load_addr, - image->arch.backup_src_start, kbuf.memsz); - } - /* Prepare elf headers and add a segment */ ret = prepare_elf_headers(image, &kbuf.buffer, &kbuf.bufsz); if (ret) diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 5dcd438ad8f2..16e125a50b33 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -298,48 +298,6 @@ static void load_segments(void) ); } -#ifdef CONFIG_KEXEC_FILE -/* Update purgatory as needed after various image segments have been prepared */ -static int arch_update_purgatory(struct kimage *image) -{ - int ret = 0; - - if (!image->file_mode) - return 0; - - /* Setup copying of backup region */ - if (image->type == KEXEC_TYPE_CRASH) { - ret = kexec_purgatory_get_set_symbol(image, - "purgatory_backup_dest", - &image->arch.backup_load_addr, - sizeof(image->arch.backup_load_addr), 0); - if (ret) - return ret; - - ret = kexec_purgatory_get_set_symbol(image, - "purgatory_backup_src", - &image->arch.backup_src_start, - sizeof(image->arch.backup_src_start), 0); - if (ret) - return ret; - - ret = kexec_purgatory_get_set_symbol(image, - "purgatory_backup_sz", - &image->arch.backup_src_sz, - sizeof(image->arch.backup_src_sz), 0); - if (ret) - return ret; - } - - return ret; -} -#else /* !CONFIG_KEXEC_FILE */ -static inline int arch_update_purgatory(struct kimage *image) -{ - return 0; -} -#endif /* CONFIG_KEXEC_FILE */ - int machine_kexec_prepare(struct kimage *image) { unsigned long start_pgtable; @@ -353,11 +311,6 @@ int machine_kexec_prepare(struct kimage *image) if (result) return result; - /* update purgatory as needed */ - result = arch_update_purgatory(image); - if (result) - return result; - return 0; } diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c index 3b95410ff0f8..2961234d0795 100644 --- a/arch/x86/purgatory/purgatory.c +++ b/arch/x86/purgatory/purgatory.c @@ -14,28 +14,10 @@ #include "../boot/string.h" -unsigned long purgatory_backup_dest __section(.kexec-purgatory); -unsigned long purgatory_backup_src __section(.kexec-purgatory); -unsigned long purgatory_backup_sz __section(.kexec-purgatory); - u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(.kexec-purgatory); struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX] __section(.kexec-purgatory); -/* - * On x86, second kernel requries first 640K of memory to boot. Copy - * first 640K to a backup region in reserved memory range so that second - * kernel can use first 640K. - */ -static int copy_backup_region(void) -{ - if (purgatory_backup_dest) { - memcpy((void *)purgatory_backup_dest, - (void *)purgatory_backup_src, purgatory_backup_sz); - } - return 0; -} - static int verify_sha256_digest(void) { struct kexec_sha_region *ptr, *end; @@ -66,7 +48,6 @@ void purgatory(void) for (;;) ; } - copy_backup_region(); } /* diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index 7dce39c8c034..262f83cad355 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -8,6 +8,7 @@ #include <asm/pgtable.h> #include <asm/realmode.h> #include <asm/tlbflush.h> +#include <asm/crash.h> struct real_mode_header *real_mode_header; u32 *trampoline_cr4_features; @@ -34,6 +35,7 @@ void __init reserve_real_mode(void) memblock_reserve(mem, size); set_real_mode_mem(mem); + crash_reserve_low_1M(); } static void __init setup_real_mode(void) |