diff options
| -rw-r--r-- | kexec/arch/i386/crashdump-x86.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c index bbc0f35..ab833d4 100644 --- a/kexec/arch/i386/crashdump-x86.c +++ b/kexec/arch/i386/crashdump-x86.c @@ -102,11 +102,10 @@ static int get_kernel_paddr(struct kexec_info *UNUSED(info), return -1; } -/* Retrieve kernel _stext symbol virtual address from /proc/kallsyms */ -static unsigned long long get_kernel_stext_sym(void) +/* Retrieve kernel symbol virtual address from /proc/kallsyms */ +static unsigned long long get_kernel_sym(const char *symbol) { const char *kallsyms = "/proc/kallsyms"; - const char *stext = "_stext"; char sym[128]; char line[128]; FILE *fp; @@ -122,13 +121,13 @@ static unsigned long long get_kernel_stext_sym(void) while(fgets(line, sizeof(line), fp) != NULL) { if (sscanf(line, "%Lx %c %s", &vaddr, &type, sym) != 3) continue; - if (strcmp(sym, stext) == 0) { - dbgprintf("kernel symbol %s vaddr = %16llx\n", stext, vaddr); + if (strcmp(sym, symbol) == 0) { + dbgprintf("kernel symbol %s vaddr = %16llx\n", symbol, vaddr); return vaddr; } } - fprintf(stderr, "Cannot get kernel %s symbol address\n", stext); + fprintf(stderr, "Cannot get kernel %s symbol address\n", symbol); return 0; } @@ -151,6 +150,8 @@ static int get_kernel_vaddr_and_size(struct kexec_info *UNUSED(info), off_t size; uint32_t elf_flags = 0; uint64_t stext_sym; + const unsigned long long pud_mask = ~((1 << 30) - 1); + unsigned long long vaddr, lowest_vaddr = 0; if (elf_info->machine != EM_X86_64) return 0; @@ -180,9 +181,23 @@ static int get_kernel_vaddr_and_size(struct kexec_info *UNUSED(info), end_phdr = &ehdr.e_phdr[ehdr.e_phnum]; + /* Search for the real PAGE_OFFSET when KASLR memory randomization + * is enabled */ + if (get_kernel_sym("page_offset_base") != 0) { + for(phdr = ehdr.e_phdr; phdr != end_phdr; phdr++) { + if (phdr->p_type == PT_LOAD) { + vaddr = phdr->p_vaddr & pud_mask; + if (lowest_vaddr == 0 || lowest_vaddr > vaddr) + lowest_vaddr = vaddr; + } + } + if (lowest_vaddr != 0) + elf_info->page_offset = lowest_vaddr; + } + /* Traverse through the Elf headers and find the region where * _stext symbol is located in. That's where kernel is mapped */ - stext_sym = get_kernel_stext_sym(); + stext_sym = get_kernel_sym("_stext"); for(phdr = ehdr.e_phdr; stext_sym && phdr != end_phdr; phdr++) { if (phdr->p_type == PT_LOAD) { unsigned long long saddr = phdr->p_vaddr; |