[Crash-utility] [PATCH] read physical memory layout from device tree

Sorry, forgot to set subject... Hello Dave, here is patch mentioned in bug https://bugzilla.redhat.com/show_bug.cgi?id=1238151. It adds new option "--dtbmem" which reads physical memory layout from provided device tree and use it for kernel virtual to physical memory address translation. This is needed because some unusual boards have sparse memory and it is impossible to translate address using offset cause memory "holes" must be considered. Fail occurs during read of "mem_section" symbol. With this patch everything works ok. I use device tree parser based on 'fdtdump' utility from device tree compiler. Of course it is just basic concept and code doesn't look good, but if this idea will be useful i'll improve it. From: Arseniy Krasnov <a.krasnov(a)samsung.com&gt; Date: Wed, 1 Jul 2015 10:26:34 +0300 Subject: [PATCH] crashtool: phys memory layout from device tree. --- Makefile | 7 +- arm.c | 39 +++++++- defs.h | 9 ++ main.c | 8 +- mem_dtb.c | 299 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 354 insertions(+), 8 deletions(-) create mode 100644 mem_dtb.c diff --git a/Makefile b/Makefile index 3c38ff5..e2188a5 100644 --- a/Makefile +++ b/Makefile @@ -70,7 +70,7 @@ CFILES=main.c tools.c global_data.c memory.c filesys.c help.c task.c \ unwind_x86_32_64.c unwind_arm.c \ xen_hyper.c xen_hyper_command.c xen_hyper_global_data.c \ xen_hyper_dump_tables.c kvmdump.c qemu.c qemu-load.c sadump.c ipcs.c \ - ramdump.c vmware_vmss.c + ramdump.c vmware_vmss.c mem_dtb.c SOURCE_FILES=${CFILES} ${GENERIC_HFILES} ${MCORE_HFILES} \ ${REDHAT_CFILES} ${REDHAT_HFILES} ${UNWIND_HFILES} \ @@ -88,7 +88,7 @@ OBJECT_FILES=main.o tools.o global_data.o memory.o filesys.o help.o task.o \ unwind_x86_32_64.o unwind_arm.o \ xen_hyper.o xen_hyper_command.o xen_hyper_global_data.o \ xen_hyper_dump_tables.o kvmdump.o qemu.o qemu-load.o sadump.o ipcs.o \ - ramdump.o vmware_vmss.o + ramdump.o vmware_vmss.o mem_dtb.o MEMORY_DRIVER_FILES=memory_driver/Makefile memory_driver/crash.c memory_driver/README @@ -345,6 +345,9 @@ help.o: ${GENERIC_HFILES} help.c memory.o: ${GENERIC_HFILES} memory.c ${CC} -c ${CRASH_CFLAGS} memory.c ${WARNING_OPTIONS} ${WARNING_ERROR} +parse.o: ${GENERIC_HFILES} mem_dtb.c + ${CC} -c ${CRASH_CFLAGS} mem_dtb.c ${WARNING_OPTIONS} ${WARNING_ERROR} + test.o: ${GENERIC_HFILES} test.c ${CC} -c ${CRASH_CFLAGS} test.c ${WARNING_OPTIONS} ${WARNING_ERROR} diff --git a/arm.c b/arm.c index 534c501..c31e6a1 100644 --- a/arm.c +++ b/arm.c @@ -85,6 +85,10 @@ static struct arm_pt_regs *panic_task_regs; #define PMD_TYPE_TABLE 1 #define PMD_TYPE_SECT_LPAE 1 +/* number of memory areas and its array */ int mems_num; struct +mem_area *dyn_mems; + static inline ulong * pmd_page_addr(ulong pmd) { @@ -1264,6 +1268,30 @@ arm_uvtop(struct task_context *tc, ulong uvaddr, physaddr_t *paddr, int verbose) return arm_vtop(uvaddr, pgd, paddr, verbose); } +static physaddr_t vtop_sparse(unsigned int vaddr) { + physaddr_t ret; + physaddr_t cur; + int i; + + ret = vaddr - machdep->kvbase; + + cur = 0; + for(i = 0;i < mems_num;i++) { + if (ret < cur + dyn_mems[i].size) { + if (i == 0) + ret += dyn_mems[0].base; + else + ret = dyn_mems[i].base + (ret - cur); + break; + } + + cur += dyn_mems[i].size; + } + + return ret; +} + /* * Translates a kernel virtual address to its physical address. cmd_vtop() sets * the verbose flag so that the pte translation gets displayed; all other @@ -1279,14 +1307,19 @@ arm_kvtop(struct task_context *tc, ulong kvaddr, physaddr_t *paddr, int verbose) return arm_lpae_vtop(kvaddr, (ulong *)vt->kernel_pgd[0], paddr, verbose); - if (!vt->vmalloc_start) { - *paddr = VTOP(kvaddr); + if (dyn_mems == NULL) + *paddr = VTOP(kvaddr); + else + *paddr = vtop_sparse(kvaddr); return TRUE; } if (!IS_VMALLOC_ADDR(kvaddr)) { - *paddr = VTOP(kvaddr); + if (dyn_mems == NULL) + *paddr = VTOP(kvaddr); + else + *paddr = vtop_sparse(kvaddr); if (!verbose) return TRUE; } diff --git a/defs.h b/defs.h index ecadc29..94e5509 100644 --- a/defs.h +++ b/defs.h @@ -6281,4 +6281,13 @@ extern int have_full_symbols(void); #define XEN_HYPERVISOR_ARCH #endif +#ifdef ARM +/* describes memory area for sparse memory systems */ struct mem_area { + physaddr_t base; + unsigned int size; +}; +int read_dtb_sparse_mem(const char *filename); #endif + #endif /* !GDB_COMMON */ diff --git a/main.c b/main.c index fd7f7a8..eeccd68 100644 --- a/main.c +++ b/main.c @@ -72,6 +72,7 @@ static struct option long_options[] = { {"no_strip", 0, 0, 0}, {"hash", required_argument, 0, 0}, {"offline", required_argument, 0, 0}, + {"dtbmem", required_argument, 0, 0}, {0, 0, 0, 0} }; @@ -291,9 +292,10 @@ main(int argc, char **argv) error(INFO, "invalid --offline argument: %s\n", optarg); program_usage(SHORT_FORM); } - } - - else { + } else if (STREQ(long_options[option_index].name, "dtbmem")) { + if (read_dtb_sparse_mem(optarg) == 0) + error(INFO, "Failed to read sparse mem config!\n"); + } else { error(INFO, "internal error: option %s unhandled\n", long_options[option_index].name); program_usage(SHORT_FORM); diff --git a/mem_dtb.c b/mem_dtb.c new file mode 100644 index 0000000..23526bc --- /dev/null +++ b/mem_dtb.c @@ -0,0 +1,299 @@ +/* + * Tiny device tree parser from 'fdtdump' application of device tree compiler. + * http://www.devicetree.org/Device_Tree_Compiler + * https://git.kernel.org/cgit/utils/dtc/dtc.git + */ +#include <stdio.h> +#include <sys/mman.h> +#include <stdint.h> +#include <fcntl.h> +#include <stdlib.h> +#include <byteswap.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <assert.h> +#include <string.h> +#include <ctype.h> +#include "defs.h" + +typedef uint32_t fdt32_t; +typedef uint64_t fdt64_t; + +#define FDT_BEGIN_NODE 0x1 /* Start node: full name */ +#define FDT_END_NODE 0x2 /* End node */ +#define FDT_PROP 0x3 /* Property: name off, + size, content */ +#define FDT_NOP 0x4 /* nop */ +#define FDT_END 0x9 + +#define EXTRACT_BYTE(x, n) ((unsigned long long)((uint8_t *)&x)[n]) +#define CPU_TO_FDT32(x) ((EXTRACT_BYTE(x, 0) << 24) | (EXTRACT_BYTE(x, 1) << 16) | \ + (EXTRACT_BYTE(x, 2) << 8) | EXTRACT_BYTE(x, 3)) #define +CPU_TO_FDT64(x) ((EXTRACT_BYTE(x, 0) << 56) | (EXTRACT_BYTE(x, 1) << 48) | \ + (EXTRACT_BYTE(x, 2) << 40) | (EXTRACT_BYTE(x, 3) << 32) | \ + (EXTRACT_BYTE(x, 4) << 24) | (EXTRACT_BYTE(x, 5) << 16) | \ + (EXTRACT_BYTE(x, 6) << 8) | EXTRACT_BYTE(x, 7)) + +#define ALIGN(x, a) (((x) + ((a) - 1)) & ~((a) - 1)) +#define PALIGN(p, a) ((void *)(ALIGN((unsigned long)(p), (a)))) +#define GET_CELL(p) (p += 4, *((const uint32_t *)(p-4))) + +#ifdef ARM +int memory_found; +int memory_node_found; + +extern struct mem_area *dyn_mems; +extern int mems_num; + +static inline uint32_t fdt32_to_cpu(fdt32_t x) { + return (uint32_t)CPU_TO_FDT32(x); +} + +static inline uint64_t fdt64_to_cpu(fdt64_t x) { + return (uint64_t)CPU_TO_FDT64(x); +} + +struct fdt_header { + fdt32_t magic; /* magic word FDT_MAGIC */ + fdt32_t totalsize; /* total size of DT block */ + fdt32_t off_dt_struct; /* offset to structure */ + fdt32_t off_dt_strings; /* offset to strings */ + fdt32_t off_mem_rsvmap; /* offset to memory reserve map */ + fdt32_t version; /* format version */ + fdt32_t last_comp_version; /* last compatible version */ + + /* version 2 fields below */ + fdt32_t boot_cpuid_phys; /* Which physical CPU id we're + booting on */ + /* version 3 fields below */ + fdt32_t size_dt_strings; /* size of the strings block */ + + /* version 17 fields below */ + fdt32_t size_dt_struct; /* size of the structure block */ +}; + +struct fdt_reserve_entry { + fdt64_t address; + fdt64_t size; +}; + +struct fdt_node_header { + fdt32_t tag; + char name[0]; +}; + +struct fdt_property { + fdt32_t tag; + fdt32_t len; + fdt32_t nameoff; + char data[0]; +}; + +static int util_is_printable_string(const void *data, int len) { + const char *s = data; + const char *ss, *se; + + /* zero length is not */ + if (len == 0) + return 0; + + /* must terminate with zero */ + if (s[len - 1] != '\0') + return 0; + + se = s + len; + + while (s < se) { + ss = s; + while (s < se && *s && isprint((unsigned char)*s)) + s++; + + /* not zero, or not done yet */ + if (*s != '\0' || s == ss) + return 0; + + s++; + } + + return 1; +} + +static int utilfdt_print_data(const char *data, int len) { + int i; + const char *s; + + /* no data, don't print */ + if (len == 0) + return; + + if (util_is_printable_string(data, len)) { + s = data; + + if (strcmp(s, "memory") == 0) { + if (memory_node_found == 1) + memory_found = 1; + } else + memory_found = 0; + + do { + s += strlen(s) + 1; + } while (s < data + len); + + } else if ((len % 4) == 0) { + const uint32_t *cell = (const uint32_t *)data; + + len /= 4; + + if (memory_found == 1) { + int k; + + /* we are on property with memory regions */ + dyn_mems = malloc((len / 2) * (sizeof *dyn_mems)); + + if (dyn_mems == NULL) + return -1; + + for (k = 0, i = 0; i < len; k++, i += 2) { + physaddr_t from; + unsigned int size; + + from = fdt32_to_cpu(cell[i]); + size = fdt32_to_cpu(cell[i + 1]); + dyn_mems[k].base = from; + dyn_mems[k].size = size; + printf("adding memregion: %08llX sz: %08X\n", + dyn_mems[k].base, dyn_mems[k].size); + } + + mems_num = k; + + return 1; + } + } + + return 0; +} + +static int parse_dt(void *blob) +{ + struct fdt_header *bph = blob; + uint32_t off_mem_rsvmap = fdt32_to_cpu(bph->off_mem_rsvmap); + uint32_t off_dt = fdt32_to_cpu(bph->off_dt_struct); + uint32_t off_str = fdt32_to_cpu(bph->off_dt_strings); + struct fdt_reserve_entry *p_rsvmap = + (struct fdt_reserve_entry *)((char *)blob + off_mem_rsvmap); + const char *p_struct = (const char *)blob + off_dt; + const char *p_strings = (const char *)blob + off_str; + uint32_t version = fdt32_to_cpu(bph->version); + uint32_t tag; + const char *p, *s, *t; + int depth, sz; + int i; + uint64_t addr, size; + + depth = 0; + + for (i = 0; ; i++) { + addr = fdt64_to_cpu(p_rsvmap[i].address); + size = fdt64_to_cpu(p_rsvmap[i].size); + + if (addr == 0 && size == 0) + break; + } + + p = p_struct; + + while ((tag = fdt32_to_cpu(GET_CELL(p))) != FDT_END) { + int res; + + if (tag == FDT_BEGIN_NODE) { + s = p; + p = PALIGN(p + strlen(s) + 1, 4); + + if (*s == '\0') + s = "/"; + + if (!strcmp(s, "memory")) + memory_node_found = 1; + + depth++; + continue; + } + + if (tag == FDT_END_NODE) { + depth--; + continue; + } + + if (tag == FDT_NOP) + continue; + + if (tag != FDT_PROP) + break; + + sz = fdt32_to_cpu(GET_CELL(p)); + s = p_strings + fdt32_to_cpu(GET_CELL(p)); + + if (version < 16 && sz >= 8) + p = PALIGN(p, 8); + + t = p; + + p = PALIGN(p + sz, 4); + + res = utilfdt_print_data(t, sz); + + /* error occured */ + if (res == -1) + return 0; + + /* memory region parsed, exit */ + if (res == 1) + return 1; + + /* again */ + } + + return 0; +} + +int read_dtb_sparse_mem(const char *dtb_file_name) { + int dt_fd; + unsigned char *p; + struct stat si; + int res; + + res = 0; + dt_fd = open(dtb_file_name, O_RDONLY); + + if (dt_fd == -1) + goto out; + + if (fstat(dt_fd, &si)) + goto out_close; + + p = mmap(NULL, si.st_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE, dt_fd, 0); + + if (p == MAP_FAILED) + goto out_close; + + res = parse_dt(p); +out_close: + close(dt_fd); +out: + return res; +} +#else +int read_dtb_sparse_mem(const char *dtb_file_name) { + error(INFO, "Sparse mem supported only for arm!\n"); + return 0; +} +#endif -- 1.9.1