>From fdceb99769eac63b82feb47c5f5eaf844722d30f Mon Sep 17 00:00:00 2001 From: qiaonuohan Date: Mon, 20 Aug 2012 14:57:04 +0800 Subject: [PATCH 2/3] support core dump file when kdump is operating --- defs.h | 3 + main.c | 2 + netdump.c | 224 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ netdump.h | 5 ++ 4 files changed, 234 insertions(+), 0 deletions(-) diff --git a/defs.h b/defs.h index d37e453..9a37864 100755 --- a/defs.h +++ b/defs.h @@ -273,6 +273,8 @@ struct number_option { #define KCORE_LOCAL (0x100) #define KCORE_ELF32 (0x200) #define KCORE_ELF64 (0x400) +#define QEMU_MEM_DUMP_KDUMP_BACKUP \ + (0x800) #define KVMDUMP_LOCAL (0x1) #define KVMDUMP_VALID() (kvm->flags & (KVMDUMP_LOCAL)) @@ -5004,6 +5006,7 @@ int proc_kcore_init(FILE *); int read_proc_kcore(int, void *, int, ulong, physaddr_t); int write_proc_kcore(int, void *, int, ulong, physaddr_t); int kcore_memory_dump(FILE *); +void qemu_mem_dump_kdump_backup_region_init(void); /* * diskdump.c diff --git a/main.c b/main.c index 9dced6e..033bfa1 100755 --- a/main.c +++ b/main.c @@ -640,6 +640,8 @@ main_loop(void) if (!(pc->flags & GDB_INIT)) { gdb_session_init(); show_untrusted_files(); + if (pc->flags2 & QEMU_MEM_DUMP) + qemu_mem_dump_kdump_backup_region_init(); if (SADUMP_DUMPFILE()) sadump_kdump_backup_region_init(); if (XEN_HYPER_MODE()) { diff --git a/netdump.c b/netdump.c index 55073dd..d7928c2 100644 --- a/netdump.c +++ b/netdump.c @@ -502,6 +502,20 @@ read_netdump(int fd, void *bufptr, int cnt, ulong addr, physaddr_t paddr) off_t offset; struct pt_load_segment *pls; int i; + + if (nd->flags & QEMU_MEM_DUMP_KDUMP_BACKUP && + paddr >= nd->backup_src_start && + paddr < nd->backup_src_start + nd->backup_src_size) { + ulong orig_paddr; + + orig_paddr = paddr; + paddr += nd->backup_offset - nd->backup_src_start; + + if (CRASHDEBUG(1)) + error(INFO, + "qemu_mem_dump: kdump backup region: %#llx => %#llx\n", + orig_paddr, paddr); + } offset = 0; @@ -3483,3 +3497,213 @@ kdump_get_osrelease(void) } else pc->flags2 &= ~GET_OSRELEASE; } + +/** + * kdump saves the first 640kB physical memory for BIOS to use the + * range on boot of 2nd kernel. qemu mem dump translates read request to the + * 640kB region as to the back up region. This function seachs kexec + * resources for the backup region. + */ +void +qemu_mem_dump_kdump_backup_region_init(void) +{ + char buf[BUFSIZE]; + ulong i, total, kexec_crash_image_p, elfcorehdr_p; + uint16_t e_phnum, e_phentsize; + ulong backup_offset; + ulong backup_src_start, backup_src_size; + int kimage_segment_len; + size_t bufsize; + + Elf64_Off e_phoff64 = 0; + Elf32_Off e_phoff32 = 0; + + if (!readmem(symbol_value("kexec_crash_image"), KVADDR, + &kexec_crash_image_p, sizeof(ulong), + "kexec backup region: kexec_crash_image", + QUIET|RETURN_ON_ERROR)) + goto error; + + if (!kexec_crash_image_p) { + if (CRASHDEBUG(1)) + error(INFO, "qemu mem dump: kexec_crash_image not loaded\n"); + return; + } + + kimage_segment_len = get_array_length("kimage.segment", NULL, + STRUCT_SIZE("kexec_segment")); + + if (!readmem(kexec_crash_image_p + MEMBER_OFFSET("kimage", "segment"), + KVADDR, buf, MEMBER_SIZE("kimage", "segment"), + "kexec backup region: kexec_crash_image->segment", + QUIET|RETURN_ON_ERROR)) + goto error; + + elfcorehdr_p = 0; + for (i = 0; i < kimage_segment_len; ++i) { + char e_ident[EI_NIDENT]; + ulong mem; + + mem = ULONG(buf + i * STRUCT_SIZE("kexec_segment") + + MEMBER_OFFSET("kexec_segment", "mem")); + if (!mem) + continue; + + if (!readmem(mem, PHYSADDR, e_ident, SELFMAG, + "elfcorehdr: e_ident", + QUIET|RETURN_ON_ERROR)) + goto error; + + if (strncmp(ELFMAG, e_ident, SELFMAG) == 0) { + elfcorehdr_p = mem; + break; + } + } + if (!elfcorehdr_p) { + if (CRASHDEBUG(1)) + error(INFO, + "qemu mem dump: elfcorehdr not found in segments of kexec_crash_image\n"); + goto error; + } + + if (nd->flags & KDUMP_ELF32) { + if (!readmem(elfcorehdr_p, PHYSADDR, buf, STRUCT_SIZE("elf32_hdr"), + "elfcorehdr", QUIET|RETURN_ON_ERROR)) + goto error; + + e_phnum = USHORT(buf + MEMBER_OFFSET("elf32_hdr", "e_phnum")); + e_phentsize = USHORT(buf + MEMBER_OFFSET("elf32_hdr", "e_phentsize")); + e_phoff32 = ULONG(buf + MEMBER_OFFSET("elf32_hdr", "e_phoff")); + } else { + if (!readmem(elfcorehdr_p, PHYSADDR, buf, STRUCT_SIZE("elf64_hdr"), + "elfcorehdr", QUIET|RETURN_ON_ERROR)) + goto error; + + e_phnum = USHORT(buf + MEMBER_OFFSET("elf64_hdr", "e_phnum")); + e_phentsize = USHORT(buf + MEMBER_OFFSET("elf64_hdr", "e_phentsize")); + e_phoff64 = ULONG(buf + MEMBER_OFFSET("elf64_hdr", "e_phoff")); + } + + backup_src_start = backup_src_size = backup_offset = 0; + + for (i = 0; i < e_phnum; ++i) { + uint32_t p_type; + Elf32_Off p_offset32 = 0; + Elf64_Off p_offset64 = 0; + Elf32_Addr p_paddr32 = 0; + Elf64_Addr p_paddr64 = 0; + uint32_t p_memsz32 = 0; + uint64_t p_memsz64 = 0; + + if (nd->flags & KDUMP_ELF32) { + if (!readmem(elfcorehdr_p + e_phoff32 + i * e_phentsize, + PHYSADDR, buf, e_phentsize, + "elfcorehdr: program header", + QUIET|RETURN_ON_ERROR)) + goto error; + + p_type = UINT(buf+MEMBER_OFFSET("elf32_phdr","p_type")); + p_offset32 = ULONG(buf+MEMBER_OFFSET("elf32_phdr","p_offset")); + p_paddr32 = ULONG(buf+MEMBER_OFFSET("elf32_phdr","p_paddr")); + p_memsz32 = ULONG(buf+MEMBER_OFFSET("elf32_phdr","p_memsz")); + } else { + if (!readmem(elfcorehdr_p + e_phoff64 + i * e_phentsize, + PHYSADDR, buf, e_phentsize, + "elfcorehdr: program header", + QUIET|RETURN_ON_ERROR)) + goto error; + + p_type = UINT(buf+MEMBER_OFFSET("elf64_phdr","p_type")); + p_offset64 = ULONG(buf+MEMBER_OFFSET("elf64_phdr","p_offset")); + p_paddr64 = ULONG(buf+MEMBER_OFFSET("elf64_phdr","p_paddr")); + p_memsz64 = ULONG(buf+MEMBER_OFFSET("elf64_phdr","p_memsz")); + } + + /* + * kexec marks backup region PT_LOAD by assigning + * backup region address in p_offset, and p_addr in + * p_offsets for other PT_LOAD entries. + */ + if (nd->flags & KDUMP_ELF32) { + if (p_type == PT_LOAD && + p_paddr32 <= KEXEC_BACKUP_SRC_END && + p_paddr32 != p_offset32) { + + backup_src_start = p_paddr32; + backup_src_size = p_memsz32; + backup_offset = p_offset32; + + if (CRASHDEBUG(1)) + error(INFO, + "qemu mem dump: kexec backup region found: " + "START: %#08lx SIZE: %#08lx OFFSET: %#08lx\n", + backup_src_start, backup_src_size, backup_offset); + + break; + } + } else { + if (p_type == PT_LOAD && + p_paddr64 <= KEXEC_BACKUP_SRC_END && + p_paddr64 != p_offset64) { + + backup_src_start = p_paddr64; + backup_src_size = p_memsz64; + backup_offset = p_offset64; + + if (CRASHDEBUG(1)) + error(INFO, + "qemu mem dump: kexec backup region found: " + "START: %#016lx SIZE: %#016lx OFFSET: %#016lx\n", + backup_src_start, backup_src_size, backup_offset); + + break; + } + } + } + + if (!backup_offset) { + if (CRASHDEBUG(1)) + error(WARNING, "qemu mem dump: backup region not found in elfcorehdr\n"); + return; + } + + bufsize = BUFSIZE; + for (total = 0; total < backup_src_size; total += bufsize) { + char backup_buf[BUFSIZE]; + int j; + + if (backup_src_size - total < BUFSIZE) + bufsize = backup_src_size - total; + + if (!readmem(backup_offset + total, PHYSADDR, backup_buf, + bufsize, "backup source", QUIET|RETURN_ON_ERROR)) + goto error; + + /* + * We're assuming the backup resion is initialized + * with 0 filled if kdump has not run. + */ + for (j = 0; j < bufsize; ++j) { + if (backup_buf[j]) { + + nd->flags |= QEMU_MEM_DUMP_KDUMP_BACKUP; + nd->backup_src_start = backup_src_start; + nd->backup_src_size = backup_src_size; + nd->backup_offset = backup_offset; + + if (CRASHDEBUG(1)) +error(INFO, "qemu mem dump: backup region is used: %lx\n", backup_offset + total + j); + + return; + } + } + } + + if (CRASHDEBUG(1)) + error(INFO, "qemu mem dump: kexec backup region not used\n"); + + return; + +error: + error(WARNING, "failed to init kexec backup region\n"); +} diff --git a/netdump.h b/netdump.h index 2e296ad..4a6d661 100644 --- a/netdump.h +++ b/netdump.h @@ -71,6 +71,11 @@ struct vmcore_data { struct xen_kdump_data *xen_kdump_data; void *vmcoreinfo; uint size_vmcoreinfo; +/* Backup Region, First 640K of System RAM. */ +#define KEXEC_BACKUP_SRC_END 0x0009ffff + ulong backup_src_start; + ulong backup_src_size; + ulong backup_offset; }; /* -- 1.7.1