diff --git a/arch/powerpc/include/asm/fadump-internal.h b/arch/powerpc/include/asm/fadump-internal.h index 27f9e11eda28..5d706a7acc8a 100644 --- a/arch/powerpc/include/asm/fadump-internal.h +++ b/arch/powerpc/include/asm/fadump-internal.h @@ -42,13 +42,38 @@ static inline u64 fadump_str_to_u64(const char *str) #define FADUMP_CPU_UNKNOWN (~((u32)0)) -#define FADUMP_CRASH_INFO_MAGIC fadump_str_to_u64("FADMPINF") +/* + * The introduction of new fields in the fadump crash info header has + * led to a change in the magic key from `FADMPINF` to `FADMPSIG` for + * identifying a kernel crash from an old kernel. + * + * To prevent the need for further changes to the magic number in the + * event of future modifications to the fadump crash info header, a + * version field has been introduced to track the fadump crash info + * header version. + * + * Consider a few points before adding new members to the fadump crash info + * header structure: + * + * - Append new members; avoid adding them in between. + * - Non-primitive members should have a size member as well. + * - For every change in the fadump header, increment the + * fadump header version. This helps the updated kernel decide how to + * handle kernel dumps from older kernels. + */ +#define FADUMP_CRASH_INFO_MAGIC_OLD fadump_str_to_u64("FADMPINF") +#define FADUMP_CRASH_INFO_MAGIC fadump_str_to_u64("FADMPSIG") +#define FADUMP_HEADER_VERSION 1 /* fadump crash info structure */ struct fadump_crash_info_header { u64 magic_number; - u64 elfcorehdr_addr; + u32 version; u32 crashing_cpu; + u64 vmcoreinfo_raddr; + u64 vmcoreinfo_size; + u32 pt_regs_sz; + u32 cpu_mask_sz; struct pt_regs regs; struct cpumask cpu_mask; }; @@ -94,6 +119,8 @@ struct fw_dump { u64 boot_mem_regs_cnt; unsigned long fadumphdr_addr; + u64 elfcorehdr_addr; + u64 elfcorehdr_size; unsigned long cpu_notes_buf_vaddr; unsigned long cpu_notes_buf_size; diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c index 4e768d93c6d4..a020597c065a 100644 --- a/arch/powerpc/kernel/fadump.c +++ b/arch/powerpc/kernel/fadump.c @@ -53,8 +53,6 @@ static struct kobject *fadump_kobj; static atomic_t cpus_in_fadump; static DEFINE_MUTEX(fadump_mutex); -static struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false }; - #define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */ #define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \ sizeof(struct fadump_memory_range)) @@ -373,12 +371,6 @@ static unsigned long __init get_fadump_area_size(void) size = PAGE_ALIGN(size); size += fw_dump.boot_memory_size; size += sizeof(struct fadump_crash_info_header); - size += sizeof(struct elfhdr); /* ELF core header.*/ - size += sizeof(struct elf_phdr); /* place holder for cpu notes */ - /* Program headers for crash memory regions. */ - size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); - - size = PAGE_ALIGN(size); /* This is to hold kernel metadata on platforms that support it */ size += (fw_dump.ops->fadump_get_metadata_size ? @@ -915,36 +907,6 @@ static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info, return 0; } -static int fadump_exclude_reserved_area(u64 start, u64 end) -{ - u64 ra_start, ra_end; - int ret = 0; - - ra_start = fw_dump.reserve_dump_area_start; - ra_end = ra_start + fw_dump.reserve_dump_area_size; - - if ((ra_start < end) && (ra_end > start)) { - if ((start < ra_start) && (end > ra_end)) { - ret = fadump_add_mem_range(&crash_mrange_info, - start, ra_start); - if (ret) - return ret; - - ret = fadump_add_mem_range(&crash_mrange_info, - ra_end, end); - } else if (start < ra_start) { - ret = fadump_add_mem_range(&crash_mrange_info, - start, ra_start); - } else if (ra_end < end) { - ret = fadump_add_mem_range(&crash_mrange_info, - ra_end, end); - } - } else - ret = fadump_add_mem_range(&crash_mrange_info, start, end); - - return ret; -} - static int fadump_init_elfcore_header(char *bufp) { struct elfhdr *elf; @@ -981,52 +943,6 @@ static int fadump_init_elfcore_header(char *bufp) return 0; } -/* - * Traverse through memblock structure and setup crash memory ranges. These - * ranges will be used create PT_LOAD program headers in elfcore header. - */ -static int fadump_setup_crash_memory_ranges(void) -{ - u64 i, start, end; - int ret; - - pr_debug("Setup crash memory ranges.\n"); - crash_mrange_info.mem_range_cnt = 0; - - /* - * Boot memory region(s) registered with firmware are moved to - * different location at the time of crash. Create separate program - * header(s) for this memory chunk(s) with the correct offset. - */ - for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { - start = fw_dump.boot_mem_addr[i]; - end = start + fw_dump.boot_mem_sz[i]; - ret = fadump_add_mem_range(&crash_mrange_info, start, end); - if (ret) - return ret; - } - - for_each_mem_range(i, &start, &end) { - /* - * skip the memory chunk that is already added - * (0 through boot_memory_top). - */ - if (start < fw_dump.boot_mem_top) { - if (end > fw_dump.boot_mem_top) - start = fw_dump.boot_mem_top; - else - continue; - } - - /* add this range excluding the reserved dump area. */ - ret = fadump_exclude_reserved_area(start, end); - if (ret) - return ret; - } - - return 0; -} - /* * If the given physical address falls within the boot memory region then * return the relocated address that points to the dump region reserved @@ -1057,36 +973,50 @@ static inline unsigned long fadump_relocate(unsigned long paddr) return raddr; } -static int fadump_create_elfcore_headers(char *bufp) +static void __init populate_elf_pt_load(struct elf_phdr *phdr, u64 start, + u64 size, unsigned long long offset) { - unsigned long long raddr, offset; - struct elf_phdr *phdr; - struct elfhdr *elf; - int i, j; + phdr->p_align = 0; + phdr->p_memsz = size; + phdr->p_filesz = size; + phdr->p_paddr = start; + phdr->p_offset = offset; + phdr->p_type = PT_LOAD; + phdr->p_flags = PF_R|PF_W|PF_X; + phdr->p_vaddr = (unsigned long)__va(start); +} +static void __init fadump_populate_elfcorehdr(struct fadump_crash_info_header *fdh) +{ + char *bufp; + struct elfhdr *elf; + struct elf_phdr *phdr; + u64 boot_mem_dest_offset; + unsigned long long i, ra_start, ra_end, ra_size, mstart, mend; + + bufp = (char *) fw_dump.elfcorehdr_addr; fadump_init_elfcore_header(bufp); elf = (struct elfhdr *)bufp; bufp += sizeof(struct elfhdr); /* - * setup ELF PT_NOTE, place holder for cpu notes info. The notes info - * will be populated during second kernel boot after crash. Hence - * this PT_NOTE will always be the first elf note. + * Set up ELF PT_NOTE, a placeholder for CPU notes information. + * The notes info will be populated later by platform-specific code. + * Hence, this PT_NOTE will always be the first ELF note. * * NOTE: Any new ELF note addition should be placed after this note. */ phdr = (struct elf_phdr *)bufp; bufp += sizeof(struct elf_phdr); phdr->p_type = PT_NOTE; - phdr->p_flags = 0; - phdr->p_vaddr = 0; - phdr->p_align = 0; - - phdr->p_offset = 0; - phdr->p_paddr = 0; - phdr->p_filesz = 0; - phdr->p_memsz = 0; - + phdr->p_flags = 0; + phdr->p_vaddr = 0; + phdr->p_align = 0; + phdr->p_offset = 0; + phdr->p_paddr = 0; + phdr->p_filesz = 0; + phdr->p_memsz = 0; + /* Increment number of program headers. */ (elf->e_phnum)++; /* setup ELF PT_NOTE for vmcoreinfo */ @@ -1096,55 +1026,66 @@ static int fadump_create_elfcore_headers(char *bufp) phdr->p_flags = 0; phdr->p_vaddr = 0; phdr->p_align = 0; - - phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); - phdr->p_offset = phdr->p_paddr; - phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; - + phdr->p_paddr = phdr->p_offset = fdh->vmcoreinfo_raddr; + phdr->p_memsz = phdr->p_filesz = fdh->vmcoreinfo_size; /* Increment number of program headers. */ (elf->e_phnum)++; - /* setup PT_LOAD sections. */ - j = 0; - offset = 0; - raddr = fw_dump.boot_mem_addr[0]; - for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) { - u64 mbase, msize; - - mbase = crash_mrange_info.mem_ranges[i].base; - msize = crash_mrange_info.mem_ranges[i].size; - if (!msize) - continue; - + /* + * Setup PT_LOAD sections. first include boot memory regions + * and then add rest of the memory regions. + */ + boot_mem_dest_offset = fw_dump.boot_mem_dest_addr; + for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { phdr = (struct elf_phdr *)bufp; bufp += sizeof(struct elf_phdr); - phdr->p_type = PT_LOAD; - phdr->p_flags = PF_R|PF_W|PF_X; - phdr->p_offset = mbase; + populate_elf_pt_load(phdr, fw_dump.boot_mem_addr[i], + fw_dump.boot_mem_sz[i], + boot_mem_dest_offset); + /* Increment number of program headers. */ + (elf->e_phnum)++; + boot_mem_dest_offset += fw_dump.boot_mem_sz[i]; + } - if (mbase == raddr) { - /* - * The entire real memory region will be moved by - * firmware to the specified destination_address. - * Hence set the correct offset. - */ - phdr->p_offset = fw_dump.boot_mem_dest_addr + offset; - if (j < (fw_dump.boot_mem_regs_cnt - 1)) { - offset += fw_dump.boot_mem_sz[j]; - raddr = fw_dump.boot_mem_addr[++j]; - } + /* Memory reserved for fadump in first kernel */ + ra_start = fw_dump.reserve_dump_area_start; + ra_size = get_fadump_area_size(); + ra_end = ra_start + ra_size; + + phdr = (struct elf_phdr *)bufp; + for_each_mem_range(i, &mstart, &mend) { + /* Boot memory regions already added, skip them now */ + if (mstart < fw_dump.boot_mem_top) { + if (mend > fw_dump.boot_mem_top) + mstart = fw_dump.boot_mem_top; + else + continue; } - phdr->p_paddr = mbase; - phdr->p_vaddr = (unsigned long)__va(mbase); - phdr->p_filesz = msize; - phdr->p_memsz = msize; - phdr->p_align = 0; + /* Handle memblock regions overlaps with fadump reserved area */ + if ((ra_start < mend) && (ra_end > mstart)) { + if ((mstart < ra_start) && (mend > ra_end)) { + populate_elf_pt_load(phdr, mstart, ra_start - mstart, mstart); + /* Increment number of program headers. */ + (elf->e_phnum)++; + bufp += sizeof(struct elf_phdr); + phdr = (struct elf_phdr *)bufp; + populate_elf_pt_load(phdr, ra_end, mend - ra_end, ra_end); + } else if (mstart < ra_start) { + populate_elf_pt_load(phdr, mstart, ra_start - mstart, mstart); + } else if (ra_end < mend) { + populate_elf_pt_load(phdr, ra_end, mend - ra_end, ra_end); + } + } else { + /* No overlap with fadump reserved memory region */ + populate_elf_pt_load(phdr, mstart, mend - mstart, mstart); + } /* Increment number of program headers. */ (elf->e_phnum)++; + bufp += sizeof(struct elf_phdr); + phdr = (struct elf_phdr *) bufp; } - return 0; } static unsigned long init_fadump_header(unsigned long addr) @@ -1159,14 +1100,25 @@ static unsigned long init_fadump_header(unsigned long addr) memset(fdh, 0, sizeof(struct fadump_crash_info_header)); fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; - fdh->elfcorehdr_addr = addr; + fdh->version = FADUMP_HEADER_VERSION; /* We will set the crashing cpu id in crash_fadump() during crash. */ fdh->crashing_cpu = FADUMP_CPU_UNKNOWN; + + /* + * The physical address and size of vmcoreinfo are required in the + * second kernel to prepare elfcorehdr. + */ + fdh->vmcoreinfo_raddr = fadump_relocate(paddr_vmcoreinfo_note()); + fdh->vmcoreinfo_size = VMCOREINFO_NOTE_SIZE; + + + fdh->pt_regs_sz = sizeof(struct pt_regs); /* * When LPAR is terminated by PYHP, ensure all possible CPUs' * register data is processed while exporting the vmcore. */ fdh->cpu_mask = *cpu_possible_mask; + fdh->cpu_mask_sz = sizeof(struct cpumask); return addr; } @@ -1174,8 +1126,6 @@ static unsigned long init_fadump_header(unsigned long addr) static int register_fadump(void) { unsigned long addr; - void *vaddr; - int ret; /* * If no memory is reserved then we can not register for firmware- @@ -1184,18 +1134,10 @@ static int register_fadump(void) if (!fw_dump.reserve_dump_area_size) return -ENODEV; - ret = fadump_setup_crash_memory_ranges(); - if (ret) - return ret; - addr = fw_dump.fadumphdr_addr; /* Initialize fadump crash info header. */ addr = init_fadump_header(addr); - vaddr = __va(addr); - - pr_debug("Creating ELF core headers at %#016lx\n", addr); - fadump_create_elfcore_headers(vaddr); /* register the future kernel dump with firmware. */ pr_debug("Registering for firmware-assisted kernel dump...\n"); @@ -1214,7 +1156,6 @@ void fadump_cleanup(void) } else if (fw_dump.dump_registered) { /* Un-register Firmware-assisted dump if it was registered. */ fw_dump.ops->fadump_unregister(&fw_dump); - fadump_free_mem_ranges(&crash_mrange_info); } if (fw_dump.ops->fadump_cleanup) @@ -1400,6 +1341,22 @@ static void fadump_release_memory(u64 begin, u64 end) fadump_release_reserved_area(tstart, end); } +static void fadump_free_elfcorehdr_buf(void) +{ + if (fw_dump.elfcorehdr_addr == 0 || fw_dump.elfcorehdr_size == 0) + return; + + /* + * Before freeing the memory of `elfcorehdr`, reset the global + * `elfcorehdr_addr` to prevent modules like `vmcore` from accessing + * invalid memory. + */ + elfcorehdr_addr = ELFCORE_ADDR_ERR; + fadump_free_buffer(fw_dump.elfcorehdr_addr, fw_dump.elfcorehdr_size); + fw_dump.elfcorehdr_addr = 0; + fw_dump.elfcorehdr_size = 0; +} + static void fadump_invalidate_release_mem(void) { mutex_lock(&fadump_mutex); @@ -1411,6 +1368,7 @@ static void fadump_invalidate_release_mem(void) fadump_cleanup(); mutex_unlock(&fadump_mutex); + fadump_free_elfcorehdr_buf(); fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM()); fadump_free_cpu_notes_buf(); @@ -1616,6 +1574,102 @@ static void __init fadump_init_files(void) return; } +static int __init fadump_setup_elfcorehdr_buf(void) +{ + int elf_phdr_cnt; + unsigned long elfcorehdr_size; + + /* + * Program header for CPU notes comes first, followed by one for + * vmcoreinfo, and the remaining program headers correspond to + * memory regions. + */ + elf_phdr_cnt = 2 + fw_dump.boot_mem_regs_cnt + memblock_num_regions(memory); + elfcorehdr_size = sizeof(struct elfhdr) + (elf_phdr_cnt * sizeof(struct elf_phdr)); + elfcorehdr_size = PAGE_ALIGN(elfcorehdr_size); + + fw_dump.elfcorehdr_addr = (u64)fadump_alloc_buffer(elfcorehdr_size); + if (!fw_dump.elfcorehdr_addr) { + pr_err("Failed to allocate %lu bytes for elfcorehdr\n", + elfcorehdr_size); + return -ENOMEM; + } + fw_dump.elfcorehdr_size = elfcorehdr_size; + return 0; +} + +/* + * Check if the fadump header of crashed kernel is compatible with fadump kernel. + * + * It checks the magic number, endianness, and size of non-primitive type + * members of fadump header to ensure safe dump collection. + */ +static bool __init is_fadump_header_compatible(struct fadump_crash_info_header *fdh) +{ + if (fdh->magic_number == FADUMP_CRASH_INFO_MAGIC_OLD) { + pr_err("Old magic number, can't process the dump.\n"); + return false; + } + + if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { + if (fdh->magic_number == swab64(FADUMP_CRASH_INFO_MAGIC)) + pr_err("Endianness mismatch between the crashed and fadump kernels.\n"); + else + pr_err("Fadump header is corrupted.\n"); + + return false; + } + + /* + * Dump collection is not safe if the size of non-primitive type members + * of the fadump header do not match between crashed and fadump kernel. + */ + if (fdh->pt_regs_sz != sizeof(struct pt_regs) || + fdh->cpu_mask_sz != sizeof(struct cpumask)) { + pr_err("Fadump header size mismatch.\n"); + return false; + } + + return true; +} + +static void __init fadump_process(void) +{ + struct fadump_crash_info_header *fdh; + + fdh = (struct fadump_crash_info_header *) __va(fw_dump.fadumphdr_addr); + if (!fdh) { + pr_err("Crash info header is empty.\n"); + goto err_out; + } + + /* Avoid processing the dump if fadump header isn't compatible */ + if (!is_fadump_header_compatible(fdh)) + goto err_out; + + /* Allocate buffer for elfcorehdr */ + if (fadump_setup_elfcorehdr_buf()) + goto err_out; + + fadump_populate_elfcorehdr(fdh); + + /* Let platform update the CPU notes in elfcorehdr */ + if (fw_dump.ops->fadump_process(&fw_dump) < 0) + goto err_out; + + /* + * elfcorehdr is now ready to be exported. + * + * set elfcorehdr_addr so that vmcore module will export the + * elfcorehdr through '/proc/vmcore'. + */ + elfcorehdr_addr = virt_to_phys((void *)fw_dump.elfcorehdr_addr); + return; + +err_out: + fadump_invalidate_release_mem(); +} + /* * Prepare for firmware-assisted dump. */ @@ -1635,12 +1689,7 @@ int __init setup_fadump(void) * saving it to the disk. */ if (fw_dump.dump_active) { - /* - * if dump process fails then invalidate the registration - * and release memory before proceeding for re-registration. - */ - if (fw_dump.ops->fadump_process(&fw_dump) < 0) - fadump_invalidate_release_mem(); + fadump_process(); } /* Initialize the kernel dump memory structure and register with f/w */ else if (fw_dump.reserve_dump_area_size) { diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c index 964f464b1b0e..767a6b19e42a 100644 --- a/arch/powerpc/platforms/powernv/opal-fadump.c +++ b/arch/powerpc/platforms/powernv/opal-fadump.c @@ -513,8 +513,8 @@ out: final_note(note_buf); pr_debug("Updating elfcore header (%llx) with cpu notes\n", - fdh->elfcorehdr_addr); - fadump_update_elfcore_header(__va(fdh->elfcorehdr_addr)); + fadump_conf->elfcorehdr_addr); + fadump_update_elfcore_header((char *)fadump_conf->elfcorehdr_addr); return 0; } @@ -526,12 +526,7 @@ static int __init opal_fadump_process(struct fw_dump *fadump_conf) if (!opal_fdm_active || !fadump_conf->fadumphdr_addr) return rc; - /* Validate the fadump crash info header */ fdh = __va(fadump_conf->fadumphdr_addr); - if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { - pr_err("Crash info header is not valid.\n"); - return rc; - } #ifdef CONFIG_OPAL_CORE /* @@ -545,18 +540,7 @@ static int __init opal_fadump_process(struct fw_dump *fadump_conf) kernel_initiated = true; #endif - rc = opal_fadump_build_cpu_notes(fadump_conf, fdh); - if (rc) - return rc; - - /* - * We are done validating dump info and elfcore header is now ready - * to be exported. set elfcorehdr_addr so that vmcore module will - * export the elfcore header through '/proc/vmcore'. - */ - elfcorehdr_addr = fdh->elfcorehdr_addr; - - return rc; + return opal_fadump_build_cpu_notes(fadump_conf, fdh); } static void opal_fadump_region_show(struct fw_dump *fadump_conf, diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.c b/arch/powerpc/platforms/pseries/rtas-fadump.c index b5853e9fcc3c..214f37788b2d 100644 --- a/arch/powerpc/platforms/pseries/rtas-fadump.c +++ b/arch/powerpc/platforms/pseries/rtas-fadump.c @@ -375,11 +375,8 @@ static int __init rtas_fadump_build_cpu_notes(struct fw_dump *fadump_conf) } final_note(note_buf); - if (fdh) { - pr_debug("Updating elfcore header (%llx) with cpu notes\n", - fdh->elfcorehdr_addr); - fadump_update_elfcore_header(__va(fdh->elfcorehdr_addr)); - } + pr_debug("Updating elfcore header (%llx) with cpu notes\n", fadump_conf->elfcorehdr_addr); + fadump_update_elfcore_header((char *)fadump_conf->elfcorehdr_addr); return 0; error_out: @@ -389,14 +386,11 @@ error_out: } /* - * Validate and process the dump data stored by firmware before exporting - * it through '/proc/vmcore'. + * Validate and process the dump data stored by the firmware, and update + * the CPU notes of elfcorehdr. */ static int __init rtas_fadump_process(struct fw_dump *fadump_conf) { - struct fadump_crash_info_header *fdh; - int rc = 0; - if (!fdm_active || !fadump_conf->fadumphdr_addr) return -EINVAL; @@ -415,25 +409,7 @@ static int __init rtas_fadump_process(struct fw_dump *fadump_conf) return -EINVAL; } - /* Validate the fadump crash info header */ - fdh = __va(fadump_conf->fadumphdr_addr); - if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { - pr_err("Crash info header is not valid.\n"); - return -EINVAL; - } - - rc = rtas_fadump_build_cpu_notes(fadump_conf); - if (rc) - return rc; - - /* - * We are done validating dump info and elfcore header is now ready - * to be exported. set elfcorehdr_addr so that vmcore module will - * export the elfcore header through '/proc/vmcore'. - */ - elfcorehdr_addr = fdh->elfcorehdr_addr; - - return 0; + return rtas_fadump_build_cpu_notes(fadump_conf); } static void rtas_fadump_region_show(struct fw_dump *fadump_conf,