RepoMirrors
/
crash
mirror of https://github.com/crash-utility/crash
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
crash/kaslr_helper.c

737 lines
19 KiB
C
Raw Permalink Blame History

/*
* kaslr_helper - helper for kaslr offset calculation
*
* Copyright (c) 2011 FUJITSU LIMITED
* Copyright (c) 2018 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Authors: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
* INDOH Takao <indou.takao@jp.fujitsu.com>
* Sergio Lopez <slp@redhat.com>
*/
#include "defs.h"
#include <elf.h>
#include <inttypes.h>
#ifdef X86_64
/*
* Get address of vector0 interrupt handler (Devide Error) from Interrupt
* Descriptor Table.
*/
static ulong
get_vec0_addr(ulong idtr)
{
struct gate_struct64 {
uint16_t offset_low;
uint16_t segment;
uint32_t ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
uint16_t offset_middle;
uint32_t offset_high;
uint32_t zero1;
} __attribute__((packed)) gate;
readmem(idtr, PHYSADDR, &gate, sizeof(gate), "idt_table", FAULT_ON_ERROR);
return ((ulong)gate.offset_high << 32)
+ ((ulong)gate.offset_middle << 16)
+ gate.offset_low;
}
/*
* Parse a string of [size[KMG] ]offset[KMG]
* Import from Linux kernel(lib/cmdline.c)
*/
static ulong
memparse(char *ptr, char **retptr)
{
char *endptr;
unsigned long long ret = strtoull(ptr, &endptr, 0);
switch (*endptr) {
case 'E':
case 'e':
ret <<= 10;
case 'P':
case 'p':
ret <<= 10;
case 'T':
case 't':
ret <<= 10;
case 'G':
case 'g':
ret <<= 10;
case 'M':
case 'm':
ret <<= 10;
case 'K':
case 'k':
ret <<= 10;
endptr++;
default:
break;
}
if (retptr)
*retptr = endptr;
return ret;
}
/*
* Find "elfcorehdr=" in the boot parameter of kernel and return the address
* of elfcorehdr.
*/
static ulong
get_elfcorehdr(ulong kaslr_offset)
{
char cmdline[BUFSIZE], *ptr;
ulong cmdline_vaddr;
ulong cmdline_paddr;
ulong buf_vaddr, buf_paddr;
char *end;
ulong elfcorehdr_addr = 0, elfcorehdr_size = 0;
int verbose = CRASHDEBUG(1)? 1: 0;
cmdline_vaddr = st->saved_command_line_vmlinux + kaslr_offset;
if (!kvtop(NULL, cmdline_vaddr, &cmdline_paddr, verbose))
return 0;
if (CRASHDEBUG(1)) {
fprintf(fp, "cmdline vaddr=%lx\n", cmdline_vaddr);
fprintf(fp, "cmdline paddr=%lx\n", cmdline_paddr);
}
if (!readmem(cmdline_paddr, PHYSADDR, &buf_vaddr, sizeof(ulong),
"saved_command_line", RETURN_ON_ERROR))
return 0;
if (!kvtop(NULL, buf_vaddr, &buf_paddr, verbose))
return 0;
if (CRASHDEBUG(1)) {
fprintf(fp, "cmdline buffer vaddr=%lx\n", buf_vaddr);
fprintf(fp, "cmdline buffer paddr=%lx\n", buf_paddr);
}
memset(cmdline, 0, BUFSIZE);
if (!readmem(buf_paddr, PHYSADDR, cmdline, BUFSIZE,
"saved_command_line", RETURN_ON_ERROR))
return 0;
ptr = strstr(cmdline, "elfcorehdr=");
if (!ptr)
return 0;
if (CRASHDEBUG(1))
fprintf(fp, "2nd kernel detected\n");
ptr += strlen("elfcorehdr=");
elfcorehdr_addr = memparse(ptr, &end);
if (*end == '@') {
elfcorehdr_size = elfcorehdr_addr;
elfcorehdr_addr = memparse(end + 1, &end);
}
if (CRASHDEBUG(1)) {
fprintf(fp, "elfcorehdr_addr=%lx\n", elfcorehdr_addr);
fprintf(fp, "elfcorehdr_size=%lx\n", elfcorehdr_size);
}
return elfcorehdr_addr;
}
/*
* Get vmcoreinfo from elfcorehdr.
* Some codes are imported from Linux kernel(fs/proc/vmcore.c)
*/
static int
get_vmcoreinfo(ulong elfcorehdr, ulong *addr, int *len)
{
unsigned char e_ident[EI_NIDENT];
Elf64_Ehdr ehdr;
Elf64_Phdr phdr;
Elf64_Nhdr nhdr;
ulong ptr;
ulong nhdr_offset = 0;
int i;
if (!readmem(elfcorehdr, PHYSADDR, e_ident, EI_NIDENT,
"EI_NIDENT", RETURN_ON_ERROR))
return FALSE;
if (e_ident[EI_CLASS] != ELFCLASS64) {
error(INFO, "Only ELFCLASS64 is supportd\n");
return FALSE;
}
if (!readmem(elfcorehdr, PHYSADDR, &ehdr, sizeof(ehdr),
"Elf64_Ehdr", RETURN_ON_ERROR))
return FALSE;
/* Sanity Check */
if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
(ehdr.e_type != ET_CORE) ||
ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
ehdr.e_version != EV_CURRENT ||
ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
ehdr.e_phnum == 0) {
error(INFO, "Invalid elf header\n");
return FALSE;
}
ptr = elfcorehdr + ehdr.e_phoff;
for (i = 0; i < ehdr.e_phnum; i++) {
ulong offset;
char name[16];
if (!readmem(ptr, PHYSADDR, &phdr, sizeof(phdr),
"Elf64_Phdr", RETURN_ON_ERROR))
return FALSE;
ptr += sizeof(phdr);
if (phdr.p_type != PT_NOTE)
continue;
offset = phdr.p_offset;
if (!readmem(offset, PHYSADDR, &nhdr, sizeof(nhdr),
"Elf64_Nhdr", RETURN_ON_ERROR))
return FALSE;
offset += DIV_ROUND_UP(sizeof(Elf64_Nhdr), sizeof(Elf64_Word))*
sizeof(Elf64_Word);
memset(name, 0, sizeof(name));
if (!readmem(offset, PHYSADDR, name, sizeof(name),
"Elf64_Nhdr name", RETURN_ON_ERROR))
return FALSE;
if(!strcmp(name, "VMCOREINFO")) {
nhdr_offset = offset;
break;
}
}
if (!nhdr_offset)
return FALSE;
*addr = nhdr_offset +
DIV_ROUND_UP(nhdr.n_namesz, sizeof(Elf64_Word))*
sizeof(Elf64_Word);
*len = nhdr.n_descsz;
if (CRASHDEBUG(1)) {
fprintf(fp, "vmcoreinfo addr=%lx\n", *addr);
fprintf(fp, "vmcoreinfo len=%d\n", *len);
}
return TRUE;
}
static int
qemu_get_nr_cpus(void)
{
if (DISKDUMP_DUMPFILE())
return diskdump_get_nr_cpus();
else if (KDUMP_DUMPFILE())
return kdump_get_nr_cpus();
return 0;
}
static int
qemu_get_cr3_cr4_idtr(int cpu, ulong *cr3, ulong *cr4, ulong *idtr)
{
QEMUCPUState *cpustat;
if (DISKDUMP_DUMPFILE())
cpustat = diskdump_get_qemucpustate(cpu);
else if (KDUMP_DUMPFILE())
cpustat = kdump_get_qemucpustate(cpu);
else
return FALSE;
if (!cpustat)
return FALSE;
*cr3 = cpustat->cr[3];
*cr4 = cpustat->cr[4];
*idtr = cpustat->idt.base;
return TRUE;
}
/*
* Check if current kaslr_offset/phys_base is for 1st kernel or 2nd kernel.
* If we are in 2nd kernel, get kaslr_offset/phys_base from vmcoreinfo.
*
* 1. Get command line and try to retrieve "elfcorehdr=" boot parameter
* 2. If "elfcorehdr=" is not found in command line, we are in 1st kernel.
* There is nothing to do.
* 3. If "elfcorehdr=" is found, we are in 2nd kernel. Find vmcoreinfo
* using "elfcorehdr=" and retrieve kaslr_offset/phys_base from vmcoreinfo.
*/
static int
get_kaslr_offset_from_vmcoreinfo(ulong orig_kaslr_offset,
ulong *kaslr_offset, ulong *phys_base)
{
ulong elfcorehdr_addr = 0;
ulong vmcoreinfo_addr;
int vmcoreinfo_len;
char *buf, *pos;
int ret = FALSE;
/* Find "elfcorehdr=" in the kernel boot parameter */
elfcorehdr_addr = get_elfcorehdr(orig_kaslr_offset);
if (!elfcorehdr_addr)
return FALSE;
/* Get vmcoreinfo from the address of "elfcorehdr=" */
if (!get_vmcoreinfo(elfcorehdr_addr, &vmcoreinfo_addr, &vmcoreinfo_len))
return FALSE;
if (!vmcoreinfo_len)
return FALSE;
if (CRASHDEBUG(1))
fprintf(fp, "Find vmcoreinfo in kdump memory\n");
buf = GETBUF(vmcoreinfo_len);
if (!readmem(vmcoreinfo_addr, PHYSADDR, buf, vmcoreinfo_len,
"vmcoreinfo", RETURN_ON_ERROR))
goto quit;
/* Get phys_base form vmcoreinfo */
pos = strstr(buf, "NUMBER(phys_base)=");
if (!pos)
goto quit;
*phys_base = strtoull(pos + strlen("NUMBER(phys_base)="), NULL, 0);
/* Get kaslr_offset form vmcoreinfo */
pos = strstr(buf, "KERNELOFFSET=");
if (!pos)
goto quit;
*kaslr_offset = strtoull(pos + strlen("KERNELOFFSET="), NULL, 16);
ret = TRUE;
quit:
FREEBUF(buf);
return ret;
}
static int
get_nr_cpus(void)
{
if (SADUMP_DUMPFILE())
return sadump_get_nr_cpus();
else if (QEMU_MEM_DUMP_NO_VMCOREINFO())
return qemu_get_nr_cpus();
else if (VMSS_DUMPFILE())
return vmware_vmss_get_nr_cpus();
return 0;
}
static int
get_cr3_cr4_idtr(int cpu, ulong *cr3, ulong *cr4, ulong *idtr)
{
if (SADUMP_DUMPFILE())
return sadump_get_cr3_cr4_idtr(cpu, cr3, cr4, idtr);
else if (QEMU_MEM_DUMP_NO_VMCOREINFO())
return qemu_get_cr3_cr4_idtr(cpu, cr3, cr4, idtr);
else if (VMSS_DUMPFILE())
return vmware_vmss_get_cr3_cr4_idtr(cpu, cr3, cr4, idtr);
return FALSE;
}
#define BANNER "Linux version"
static int
verify_kaslr_offset(ulong kaslr_offset)
{
char buf[sizeof(BANNER)];
ulong linux_banner_paddr;
if (!kvtop(NULL, st->linux_banner_vmlinux + kaslr_offset,
&linux_banner_paddr, CRASHDEBUG(1)))
return FALSE;
if (!readmem(linux_banner_paddr, PHYSADDR, buf, sizeof(buf),
"linux_banner", RETURN_ON_ERROR))
return FALSE;
if (!STRNEQ(buf, BANNER))
return FALSE;
return TRUE;
}
/*
* Find virtual (VA) and physical (PA) addresses of kernel start
*
* va:
* Actual address of the kernel start (_stext) placed
* randomly by kaslr feature. To be more accurate,
* VA = _stext(from vmlinux) + kaslr_offset
*
* pa:
* Physical address where the kerenel is placed.
*
* In nokaslr case, VA = _stext (from vmlinux)
* In kaslr case, virtual address of the kernel placement goes
* in this range: ffffffff80000000..ffffffff9fffffff, or
* __START_KERNEL_map..+512MB
*
* https://www.kernel.org/doc/Documentation/x86/x86_64/mm.txt
*
* Randomized VA will be the first valid page starting from
* ffffffff80000000 (__START_KERNEL_map). Page tree entry of
* this page will contain the PA of the kernel start.
*/
static int
find_kernel_start(uint64_t pgd, ulong *va, ulong *pa)
{
int pgd_idx, p4d_idx, pud_idx, pmd_idx, pte_idx;
uint64_t pgd_pte = 0, pud_pte, pmd_pte, pte;
pgd_idx = pgd_index(__START_KERNEL_map);
if (machdep->flags & VM_5LEVEL)
p4d_idx = p4d_index(__START_KERNEL_map);
pud_idx = pud_index(__START_KERNEL_map);
pmd_idx = pmd_index(__START_KERNEL_map);
pte_idx = pte_index(__START_KERNEL_map);
/* If the VM is in 5-level page table */
if (machdep->flags & VM_5LEVEL)
*va = ~((1UL << 57) - 1);
else
*va = ~__VIRTUAL_MASK;
FILL_PGD(pgd & PHYSICAL_PAGE_MASK, PHYSADDR, PAGESIZE());
for (; pgd_idx < PTRS_PER_PGD; pgd_idx++) {
pgd_pte = ULONG(machdep->pgd + pgd_idx * sizeof(uint64_t));
if (pgd_pte & _PAGE_PRESENT)
break;
p4d_idx = pud_idx = pmd_idx = pte_idx = 0;
}
if (pgd_idx == PTRS_PER_PGD)
return FALSE;
*va |= (ulong)pgd_idx << __PGDIR_SHIFT;
if (machdep->flags & VM_5LEVEL) {
FILL_P4D(pgd_pte & PHYSICAL_PAGE_MASK, PHYSADDR, PAGESIZE());
for (; p4d_idx < PTRS_PER_P4D; p4d_idx++) {
/* reuse pgd_pte */
pgd_pte = ULONG(machdep->machspec->p4d + p4d_idx * sizeof(uint64_t));
if (pgd_pte & _PAGE_PRESENT)
break;
pud_idx = pmd_idx = pte_idx = 0;
}
if (p4d_idx == PTRS_PER_P4D)
return FALSE;
*va |= (ulong)p4d_idx << P4D_SHIFT;
}
FILL_PUD(pgd_pte & PHYSICAL_PAGE_MASK, PHYSADDR, PAGESIZE());
for (; pud_idx < PTRS_PER_PUD; pud_idx++) {
pud_pte = ULONG(machdep->pud + pud_idx * sizeof(uint64_t));
if (pud_pte & _PAGE_PRESENT)
break;
pmd_idx = pte_idx = 0;
}
if (pud_idx == PTRS_PER_PUD)
return FALSE;
*va |= (ulong)pud_idx << PUD_SHIFT;
if (pud_pte & _PAGE_PSE) {
/* 1GB page */
*pa = pud_pte & PHYSICAL_PAGE_MASK;
return TRUE;
}
FILL_PMD(pud_pte & PHYSICAL_PAGE_MASK, PHYSADDR, PAGESIZE());
for (; pmd_idx < PTRS_PER_PMD; pmd_idx++) {
pmd_pte = ULONG(machdep->pmd + pmd_idx * sizeof(uint64_t));
if (pmd_pte & _PAGE_PRESENT)
break;
pte_idx = 0;
}
if (pmd_idx == PTRS_PER_PMD)
return FALSE;
*va |= pmd_idx << PMD_SHIFT;
if (pmd_pte & _PAGE_PSE) {
/* 2MB page */
*pa = pmd_pte & PHYSICAL_PAGE_MASK;
return TRUE;
}
FILL_PTBL(pmd_pte & PHYSICAL_PAGE_MASK, PHYSADDR, PAGESIZE());
for (; pte_idx < PTRS_PER_PTE; pte_idx++) {
pte = ULONG(machdep->ptbl + pte_idx * sizeof(uint64_t));
if (pte & _PAGE_PRESENT)
break;
}
if (pte_idx == PTRS_PER_PTE)
return FALSE;
*va |= pte_idx << PAGE_SHIFT;
*pa = pmd_pte & PHYSICAL_PAGE_MASK;
return TRUE;
}
/*
* Page Tables based method to calculate kaslr_offset and phys_base.
* It uses VA and PA of kernel start.
*
* kaslr offset and phys_base are calculated as follows:
*
* kaslr_offset = VA - st->_stext_vmlinux
* phys_base = PA - (VA - __START_KERNEL_map)
*/
static int
calc_kaslr_offset_from_page_tables(uint64_t pgd, ulong *kaslr_offset,
ulong *phys_base)
{
ulong va, pa;
if (!st->_stext_vmlinux || st->_stext_vmlinux == UNINITIALIZED) {
fprintf(fp, "%s: st->_stext_vmlinux must be initialized\n",
__FUNCTION__);
return FALSE;
}
if (!find_kernel_start(pgd, &va, &pa))
return FALSE;
if (CRASHDEBUG(1)) {
fprintf(fp, "calc_kaslr_offset: _stext(vmlinux): %lx\n", st->_stext_vmlinux);
fprintf(fp, "calc_kaslr_offset: kernel start VA: %lx\n", va);
fprintf(fp, "calc_kaslr_offset: kernel start PA: %lx\n", pa);
}
*kaslr_offset = va - st->_stext_vmlinux;
*phys_base = pa - (va - __START_KERNEL_map);
return TRUE;
}
/*
* IDT based method to calculate kaslr_offset and phys_base
*
* kaslr offset and phys_base are calculated as follows:
*
* kaslr_offset:
* 1) Get IDTR and CR3 value from the dump header.
* 2) Get a virtual address of IDT from IDTR value
* --- (A)
* 3) Translate (A) to physical address using CR3, the upper 52 bits
* of which points a top of page table.
* --- (B)
* 4) Get an address of vector0 (Devide Error) interrupt handler from
* IDT, which are pointed by (B).
* --- (C)
* 5) Get an address of symbol "divide_error" form vmlinux
* --- (D)
*
* Now we have two addresses:
* (C)-> Actual address of "divide_error"
* (D)-> Original address of "divide_error" in the vmlinux
*
* kaslr_offset can be calculated by the difference between these two
* value.
*
* phys_base;
* 1) Get IDT virtual address from vmlinux
* --- (E)
*
* So phys_base can be calculated using relationship of directly mapped
* address.
*
* phys_base =
* Physical address(B) -
* (Virtual address(E) + kaslr_offset - __START_KERNEL_map)
*
* Note that the address (A) cannot be used instead of (E) because (A) is
* not direct map address, it's a fixed map address.
*
* NOTE: This solution works in most every case, but does not work in the
* following case. If the dump is captured on early stage of kernel boot,
* IDTR points to the early IDT table(early_idts) instead of normal
* IDT(idt_table). Need enhancement.
*/
static int
calc_kaslr_offset_from_idt(uint64_t idtr, uint64_t pgd, ulong *kaslr_offset, ulong *phys_base)
{
uint64_t idtr_paddr;
ulong divide_error_vmcore;
int verbose = CRASHDEBUG(1)? 1: 0;
if (!idtr)
return FALSE;
/* Convert virtual address of IDT table to physical address */
if (!kvtop(NULL, idtr, &idtr_paddr, verbose))
return FALSE;
/* Now we can calculate kaslr_offset and phys_base */
divide_error_vmcore = get_vec0_addr(idtr_paddr);
*kaslr_offset = divide_error_vmcore - st->divide_error_vmlinux;
*phys_base = idtr_paddr -
(st->idt_table_vmlinux + *kaslr_offset - __START_KERNEL_map);
if (verbose) {
fprintf(fp, "calc_kaslr_offset: idtr=%lx\n", idtr);
fprintf(fp, "calc_kaslr_offset: pgd=%lx\n", pgd);
fprintf(fp, "calc_kaslr_offset: idtr(phys)=%lx\n", idtr_paddr);
fprintf(fp, "calc_kaslr_offset: divide_error(vmlinux): %lx\n",
st->divide_error_vmlinux);
fprintf(fp, "calc_kaslr_offset: divide_error(vmcore): %lx\n",
divide_error_vmcore);
}
return TRUE;
}
/*
* Calculate kaslr_offset and phys_base
*
* kaslr_offset:
* The difference between original address in System.map or vmlinux and
* actual address placed randomly by kaslr feature. To be more accurate,
* kaslr_offset = actual address - original address
*
* phys_base:
* Physical address where the kerenel is placed. In other words, it's a
* physical address of __START_KERNEL_map. This is also decided randomly by
* kaslr.
*
* It walks through all available CPUs registers to calculate the offset/base.
*
* Also, it considers the case where dump is captured whle kdump is working,
* IDTR points to the IDT table of 2nd kernel, not 1st kernel.
* In that case, get kaslr_offset and phys_base as follows.
*
* 1) Get kaslr_offset and phys_base using the above solution.
* 2) Get kernel boot parameter from "saved_command_line"
* 3) If "elfcorehdr=" is not included in boot parameter, we are in the
* first kernel, nothing to do any more.
* 4) If "elfcorehdr=" is included in boot parameter, we are in the 2nd
* kernel. Retrieve vmcoreinfo from address of "elfcorehdr=" and
* get kaslr_offset and phys_base from vmcoreinfo.
*/
#define PTI_USER_PGTABLE_BIT PAGE_SHIFT
#define PTI_USER_PGTABLE_MASK (1 << PTI_USER_PGTABLE_BIT)
#define CR3_PCID_MASK 0xFFFull
#define CR4_LA57 (1 << 12)
int
calc_kaslr_offset(ulong *ko, ulong *pb)
{
uint64_t cr3 = 0, cr4 = 0, idtr = 0, pgd = 0;
ulong kaslr_offset, phys_base;
ulong kaslr_offset_kdump, phys_base_kdump;
int cpu, nr_cpus;
if (!machine_type("X86_64"))
return FALSE;
nr_cpus = get_nr_cpus();
for (cpu = 0; cpu < nr_cpus; cpu++) {
if (!get_cr3_cr4_idtr(cpu, &cr3, &cr4, &idtr))
continue;
if (!cr3)
continue;
if (st->pti_init_vmlinux || st->kaiser_init_vmlinux)
pgd = cr3 & ~(CR3_PCID_MASK|PTI_USER_PGTABLE_MASK);
else
pgd = cr3 & ~CR3_PCID_MASK;
/*
* Set up for kvtop.
*
* calc_kaslr_offset() is called before machdep_init(PRE_GDB), so some
* variables are not initialized yet. Set up them here to call kvtop().
*
* TODO: XEN is not supported
*/
vt->kernel_pgd[0] = pgd;
machdep->last_pgd_read = vt->kernel_pgd[0];
if (cr4 & CR4_LA57) {
machdep->flags |= VM_5LEVEL;
machdep->machspec->physical_mask_shift = __PHYSICAL_MASK_SHIFT_5LEVEL;
machdep->machspec->pgdir_shift = PGDIR_SHIFT_5LEVEL;
machdep->machspec->ptrs_per_pgd = PTRS_PER_PGD_5LEVEL;
if ((machdep->machspec->p4d = (char *)malloc(PAGESIZE())) == NULL)
error(FATAL, "cannot malloc p4d space.");
machdep->machspec->last_p4d_read = 0;
} else {
machdep->machspec->physical_mask_shift = __PHYSICAL_MASK_SHIFT_2_6;
machdep->machspec->pgdir_shift = PGDIR_SHIFT;
machdep->machspec->ptrs_per_pgd = PTRS_PER_PGD;
}
if (!readmem(pgd, PHYSADDR, machdep->pgd, PAGESIZE(),
"pgd", RETURN_ON_ERROR))
continue;
if (!calc_kaslr_offset_from_page_tables(pgd, &kaslr_offset,
&phys_base)) {
if (!calc_kaslr_offset_from_idt(idtr, pgd,
&kaslr_offset,
&phys_base))
continue;
}
if (verify_kaslr_offset(kaslr_offset))
goto found;
}
vt->kernel_pgd[0] = 0;
machdep->last_pgd_read = 0;
return FALSE;
found:
/*
* Check if current kaslr_offset/phys_base is for 1st kernel or 2nd
* kernel. If we are in 2nd kernel, get kaslr_offset/phys_base
* from vmcoreinfo
*/
if (get_kaslr_offset_from_vmcoreinfo(kaslr_offset, &kaslr_offset_kdump,
&phys_base_kdump)) {
kaslr_offset = kaslr_offset_kdump;
phys_base = phys_base_kdump;
} else if (CRASHDEBUG(1)) {
fprintf(fp, "kaslr_helper: failed to determine which kernel was running at crash,\n");
fprintf(fp, "kaslr_helper: asssuming the kdump 1st kernel.\n");
}
if (CRASHDEBUG(1)) {
fprintf(fp, "calc_kaslr_offset: kaslr_offset=%lx\n",
kaslr_offset);
fprintf(fp, "calc_kaslr_offset: phys_base=%lx\n", phys_base);
}
*ko = kaslr_offset;
*pb = phys_base;
vt->kernel_pgd[0] = 0;
machdep->last_pgd_read = 0;
return TRUE;
}
#else
int
calc_kaslr_offset(ulong *kaslr_offset, ulong *phys_page)
{
return FALSE;
}
#endif /* X86_64 */
Reference in New Issue View Git Blame Copy Permalink