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mips.c
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mips.c
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/*
* mips.c - core analysis suite
*
* Copyright (C) 2015 Rabin Vincent <rabin rab in>
*
* 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.
*/
#ifdef MIPS
#include <elf.h>
#include "defs.h"
/* From arch/mips/asm/include/pgtable{,-32}.h */
typedef ulong pgd_t;
typedef ulong pte_t;
#define PTE_ORDER 0
#define PGD_T_LOG2 (__builtin_ffs(sizeof(pgd_t)) - 1)
#define PTE_T_LOG2 (__builtin_ffs(sizeof(pte_t)) - 1)
#define __PGD_ORDER (32 - 3 * (int)PAGESHIFT() + PGD_T_LOG2 + PTE_T_LOG2)
#define PGD_ORDER (__PGD_ORDER >= 0 ? __PGD_ORDER : 0)
#define PGD_SIZE (PAGESIZE() << PGD_ORDER)
#define PGDIR_SHIFT (2 * PAGESHIFT() + PTE_ORDER - PTE_T_LOG2)
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
#define USER_PTRS_PER_PGD (0x80000000UL/PGDIR_SIZE)
#define PTRS_PER_PGD (USER_PTRS_PER_PGD * 2)
#define PTRS_PER_PTE ((PAGESIZE() << PTE_ORDER) / sizeof(pte_t))
#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
#define pte_offset(address) \
(((address) >> PAGESHIFT()) & (PTRS_PER_PTE - 1))
#define MIPS_CPU_RIXI 0x00800000llu
#define MIPS32_EF_R0 6
#define MIPS32_EF_R29 35
#define MIPS32_EF_R31 37
#define MIPS32_EF_LO 38
#define MIPS32_EF_HI 39
#define MIPS32_EF_CP0_EPC 40
#define MIPS32_EF_CP0_BADVADDR 41
#define MIPS32_EF_CP0_STATUS 42
#define MIPS32_EF_CP0_CAUSE 43
static struct machine_specific mips_machine_specific = { 0 };
/*
* Holds registers during the crash.
*/
static struct mips_regset *panic_task_regs;
static void
mips_display_machine_stats(void)
{
fprintf(fp, " HZ: %d\n", machdep->hz);
fprintf(fp, " PAGE SIZE: %d\n", PAGESIZE());
fprintf(fp, "\n");
#define PRINT_PAGE_FLAG(flag) \
if (flag) \
fprintf(fp, " %14s: %08lx\n", #flag, flag)
PRINT_PAGE_FLAG(_PAGE_PRESENT);
PRINT_PAGE_FLAG(_PAGE_READ);
PRINT_PAGE_FLAG(_PAGE_WRITE);
PRINT_PAGE_FLAG(_PAGE_ACCESSED);
PRINT_PAGE_FLAG(_PAGE_MODIFIED);
PRINT_PAGE_FLAG(_PAGE_GLOBAL);
PRINT_PAGE_FLAG(_PAGE_VALID);
PRINT_PAGE_FLAG(_PAGE_NO_READ);
PRINT_PAGE_FLAG(_PAGE_NO_EXEC);
PRINT_PAGE_FLAG(_PAGE_DIRTY);
}
static void
mips_cmd_mach(void)
{
int c;
while ((c = getopt(argcnt, args, "")) != EOF) {
switch(c) {
default:
argerrs++;
break;
}
}
if (argerrs)
cmd_usage(pc->curcmd, SYNOPSIS);
mips_display_machine_stats();
}
#define PGDIR_OFFSET(X) (((ulong)(X)) & (PGD_SIZE - 1))
static void
mips_init_page_flags(void)
{
ulong shift = 0;
_PAGE_PRESENT = 1UL << shift++;
if (THIS_KERNEL_VERSION >= LINUX(4,1,0)) {
_PAGE_WRITE = 1UL << shift++;
_PAGE_ACCESSED = 1UL << shift++;
_PAGE_MODIFIED = 1UL << shift++;
_PAGE_NO_EXEC = 1UL << shift++;
_PAGE_READ = _PAGE_NO_READ = 1UL << shift++;
} else {
ulonglong cpu_options;
int rixi;
ulong addr;
addr = symbol_value("cpu_data") +
MEMBER_OFFSET("cpuinfo_mips", "options");
readmem(addr, KVADDR, &cpu_options, sizeof(cpu_options),
"cpu_data[0].options", FAULT_ON_ERROR);
rixi = cpu_options & MIPS_CPU_RIXI;
if (!rixi)
_PAGE_READ = 1UL << shift++;
_PAGE_WRITE = 1UL << shift++;
_PAGE_ACCESSED = 1UL << shift++;
_PAGE_MODIFIED = 1UL << shift++;
if (rixi) {
_PAGE_NO_EXEC = 1UL << shift++;
_PAGE_NO_READ = 1UL << shift++;
}
}
_PAGE_GLOBAL = 1UL << shift++;
_PAGE_VALID = 1UL << shift++;
_PAGE_DIRTY = 1UL << shift++;
_PFN_SHIFT = PAGESHIFT() - 12 + shift + 3;
}
static int
mips_translate_pte(ulong pte, void *physaddr, ulonglong pte64)
{
char ptebuf[BUFSIZE];
char physbuf[BUFSIZE];
char buf[BUFSIZE];
int present;
ulong paddr;
int len1, len2, others;
present = pte & _PAGE_PRESENT;
paddr = (pte >> _PFN_SHIFT) << PAGESHIFT();
if (physaddr) {
*(ulong *)physaddr = PAGEBASE(pte);
return !!present;
}
sprintf(ptebuf, "%lx", pte);
len1 = MAX(strlen(ptebuf), strlen("PTE"));
fprintf(fp, "%s ", mkstring(buf, len1, CENTER | LJUST, "PTE"));
if (!present)
return !!present;
sprintf(physbuf, "%lx", paddr);
len2 = MAX(strlen(physbuf), strlen("PHYSICAL"));
fprintf(fp, "%s ", mkstring(buf, len2, CENTER | LJUST, "PHYSICAL"));
fprintf(fp, "FLAGS\n");
fprintf(fp, "%s %s ",
mkstring(ptebuf, len1, CENTER | RJUST, NULL),
mkstring(physbuf, len2, CENTER | RJUST, NULL));
fprintf(fp, "(");
others = 0;
#define CHECK_PAGE_FLAG(flag) \
if ((_PAGE_##flag) && (pte & _PAGE_##flag)) \
fprintf(fp, "%s" #flag, others++ ? "|" : "")
if (pte) {
CHECK_PAGE_FLAG(PRESENT);
CHECK_PAGE_FLAG(READ);
CHECK_PAGE_FLAG(WRITE);
CHECK_PAGE_FLAG(ACCESSED);
CHECK_PAGE_FLAG(MODIFIED);
CHECK_PAGE_FLAG(GLOBAL);
CHECK_PAGE_FLAG(VALID);
CHECK_PAGE_FLAG(NO_READ);
CHECK_PAGE_FLAG(NO_EXEC);
CHECK_PAGE_FLAG(DIRTY);
} else {
fprintf(fp, "no mapping");
}
fprintf(fp, ")\n");
return !!present;
}
static int
mips_pgd_vtop(ulong *pgd, ulong vaddr, physaddr_t *paddr, int verbose)
{
ulong invalid_pte_table = symbol_value("invalid_pte_table");
ulong *page_dir;
ulong pgd_pte, page_table;
ulong pte;
ulong pbase;
if (verbose) {
const char *segment;
if (vaddr < 0x80000000lu)
segment = "useg";
else if (vaddr < 0xa0000000lu)
segment = "kseg0";
else if (vaddr < 0xc0000000lu)
segment = "kseg1";
else if (vaddr < 0xe0000000lu)
segment = "ksseg";
else
segment = "kseg3";
fprintf(fp, "SEGMENT: %s\n", segment);
}
if (vaddr >= 0x80000000lu && vaddr < 0xc0000000lu) {
*paddr = VTOP(vaddr);
return TRUE;
}
if (verbose)
fprintf(fp, "PAGE DIRECTORY: %lx\n", (ulong)pgd);
page_dir = pgd + pgd_index(vaddr);
FILL_PGD(PAGEBASE(pgd), KVADDR, PGD_SIZE);
pgd_pte = ULONG(machdep->pgd + PGDIR_OFFSET(page_dir));
if (verbose)
fprintf(fp, " PGD: %08lx => %lx\n", (ulong)page_dir, pgd_pte);
if (pgd_pte == invalid_pte_table) {
fprintf(fp, "invalid\n");
return FALSE;
}
page_table = VTOP(pgd_pte) + sizeof(pte_t) * pte_offset(vaddr);
FILL_PTBL(PAGEBASE(page_table), PHYSADDR, PAGESIZE());
pte = ULONG(machdep->ptbl + PAGEOFFSET(page_table));
if (verbose)
fprintf(fp, " PTE: %08lx => %08lx\n", page_table, pte);
if (!(pte & _PAGE_PRESENT)) {
if (verbose) {
fprintf(fp, "\n");
mips_translate_pte((ulong)pte, 0, pte);
}
return FALSE;
}
pbase = (pte >> _PFN_SHIFT) << PAGESHIFT();
*paddr = pbase + PAGEOFFSET(vaddr);
if (verbose) {
fprintf(fp, " PAGE: %08lx\n\n", pbase);
mips_translate_pte(pte, 0, 0);
}
return TRUE;
}
static int
mips_uvtop(struct task_context *tc, ulong vaddr, physaddr_t *paddr, int verbose)
{
ulong *pgd;
if (!tc)
error(FATAL, "current context invalid\n");
if (is_kernel_thread(tc->task) && IS_KVADDR(vaddr)) {
ulong active_mm;
readmem(tc->task + OFFSET(task_struct_active_mm),
KVADDR, &active_mm, sizeof(void *),
"task active_mm contents", FAULT_ON_ERROR);
if (!active_mm)
error(FATAL,
"no active_mm for this kernel thread\n");
readmem(active_mm + OFFSET(mm_struct_pgd),
KVADDR, &pgd, sizeof(long),
"mm_struct pgd", FAULT_ON_ERROR);
} else {
ulong mm;
mm = task_mm(tc->task, TRUE);
if (mm)
pgd = ULONG_PTR(tt->mm_struct + OFFSET(mm_struct_pgd));
else
readmem(tc->mm_struct + OFFSET(mm_struct_pgd),
KVADDR, &pgd, sizeof(long), "mm_struct pgd",
FAULT_ON_ERROR);
}
return mips_pgd_vtop(pgd, vaddr, paddr, verbose);
}
static int
mips_kvtop(struct task_context *tc, ulong kvaddr, physaddr_t *paddr, int verbose)
{
if (!IS_KVADDR(kvaddr))
return FALSE;
if (!verbose && !IS_VMALLOC_ADDR(kvaddr)) {
*paddr = VTOP(kvaddr);
return TRUE;
}
return mips_pgd_vtop((ulong *)vt->kernel_pgd[0], kvaddr, paddr,
verbose);
}
static void
mips_dump_exception_stack(struct bt_info *bt, char *pt_regs)
{
struct mips_pt_regs_main *mains;
struct mips_pt_regs_cp0 *cp0;
int i;
char buf[BUFSIZE];
mains = (struct mips_pt_regs_main *) (pt_regs + OFFSET(pt_regs_regs));
cp0 = (struct mips_pt_regs_cp0 *) \
(pt_regs + OFFSET(pt_regs_cp0_badvaddr));
for (i = 0; i < 32; i += 4) {
fprintf(fp, " $%2d : %08lx %08lx %08lx %08lx\n",
i, mains->regs[i], mains->regs[i+1],
mains->regs[i+2], mains->regs[i+3]);
}
fprintf(fp, " Hi : %08lx\n", mains->hi);
fprintf(fp, " Lo : %08lx\n", mains->lo);
value_to_symstr(cp0->cp0_epc, buf, 16);
fprintf(fp, " epc : %08lx %s\n", cp0->cp0_epc, buf);
value_to_symstr(mains->regs[31], buf, 16);
fprintf(fp, " ra : %08lx %s\n", mains->regs[31], buf);
fprintf(fp, " Status: %08lx\n", mains->cp0_status);
fprintf(fp, " Cause : %08lx\n", cp0->cp0_cause);
fprintf(fp, " BadVA : %08lx\n", cp0->cp0_badvaddr);
}
struct mips_unwind_frame {
ulong sp;
ulong pc;
ulong ra;
};
static void
mips_display_full_frame(struct bt_info *bt, struct mips_unwind_frame *current,
struct mips_unwind_frame *previous)
{
ulong words, addr;
ulong *up;
char buf[BUFSIZE];
int i, u_idx;
if (!INSTACK(previous->sp, bt) || !INSTACK(current->sp, bt))
return;
words = (previous->sp - current->sp) / sizeof(ulong);
if (words == 0) {
fprintf(fp, " (no frame)\n");
return;
}
addr = current->sp;
u_idx = (current->sp - bt->stackbase) / sizeof(ulong);
for (i = 0; i < words; i++, u_idx++) {
if ((i % 4) == 0)
fprintf(fp, "%s %lx: ", i ? "\n" : "", addr);
up = (ulong *)(&bt->stackbuf[u_idx * sizeof(ulong)]);
fprintf(fp, "%s ", format_stack_entry(bt, buf, *up, 0));
addr += sizeof(ulong);
}
fprintf(fp, "\n");
}
static int
mips_is_exception_entry(struct syment *sym)
{
return STREQ(sym->name, "ret_from_exception") ||
STREQ(sym->name, "ret_from_irq") ||
STREQ(sym->name, "work_resched") ||
STREQ(sym->name, "handle_sys");
}
static void
mips_dump_backtrace_entry(struct bt_info *bt, struct syment *sym,
struct mips_unwind_frame *current,
struct mips_unwind_frame *previous, int level)
{
const char *name = sym ? sym->name : "(invalid)";
struct load_module *lm;
char *name_plus_offset;
char buf[BUFSIZE];
name_plus_offset = NULL;
if (bt->flags & BT_SYMBOL_OFFSET) {
struct syment *symp;
ulong symbol_offset;
symp = value_search(current->pc, &symbol_offset);
if (symp && symbol_offset)
name_plus_offset =
value_to_symstr(current->pc, buf, bt->radix);
}
fprintf(fp, "%s#%d [%8lx] %s at %lx", level < 10 ? " " : "", level,
current->sp, name_plus_offset ? name_plus_offset : name,
current->pc);
if (module_symbol(current->pc, NULL, &lm, NULL, 0))
fprintf(fp, " [%s]", lm->mod_name);
fprintf(fp, "\n");
if (bt->flags & BT_LINE_NUMBERS) {
char buf[BUFSIZE];
get_line_number(current->pc, buf, FALSE);
if (strlen(buf))
fprintf(fp, " %s\n", buf);
}
if (sym && mips_is_exception_entry(sym)) {
char pt_regs[SIZE(pt_regs)];
GET_STACK_DATA(current->sp, &pt_regs, SIZE(pt_regs));
mips_dump_exception_stack(bt, pt_regs);
}
if (bt->flags & BT_FULL) {
fprintf(fp, " "
"[PC: %08lx RA: %08lx SP: %08lx SIZE: %ld]\n",
current->pc, current->ra, current->sp,
previous->sp - current->sp);
mips_display_full_frame(bt, current, previous);
}
}
static void
mips_analyze_function(ulong start, ulong offset,
struct mips_unwind_frame *current,
struct mips_unwind_frame *previous)
{
ulong rapos = 0;
ulong spadjust = 0;
ulong *funcbuf, *ip;
ulong i;
if (CRASHDEBUG(8))
fprintf(fp, "%s: start %#lx offset %#lx\n",
__func__, start, offset);
if (!offset) {
previous->sp = current->sp;
return;
}
ip = funcbuf = (ulong *)GETBUF(offset);
if (!readmem(start, KVADDR, funcbuf, offset,
"mips_analyze_function", RETURN_ON_ERROR)) {
FREEBUF(funcbuf);
error(FATAL, "Cannot read function at %8x", start);
return;
}
for (i = 0; i < offset; i += 4) {
ulong insn = *ip;
ulong high = (insn >> 16) & 0xffff;
ulong low = insn & 0xffff;
if (CRASHDEBUG(8))
fprintf(fp, "insn @ %#lx = %#lx\n", start + i, insn);
if (high == 0x27bd) { /* ADDIU sp, sp, imm */
if (!(low & 0x8000))
break;
spadjust += 0x10000 - low;
if (CRASHDEBUG(8))
fprintf(fp, "spadjust = %lu\n", spadjust);
} else if (high == 0xafbf) { /* SW RA, imm(SP) */
rapos = current->sp + low;
if (CRASHDEBUG(8))
fprintf(fp, "rapos %lx\n", rapos);
break;
}
ip++;
}
FREEBUF(funcbuf);
previous->sp = current->sp + spadjust;
if (rapos && !readmem(rapos, KVADDR, ¤t->ra,
sizeof(current->ra), "RA from stack",
RETURN_ON_ERROR)) {
error(FATAL, "Cannot read RA from stack %lx", rapos);
return;
}
}
static void
mips_back_trace_cmd(struct bt_info *bt)
{
struct mips_unwind_frame current, previous;
int level = 0;
int invalid_ok = 1;
if (bt->flags & BT_REGS_NOT_FOUND)
return;
previous.sp = previous.pc = previous.ra = 0;
current.pc = bt->instptr;
current.sp = bt->stkptr;
current.ra = 0;
if (bt->machdep) {
struct mips_regset *regs = bt->machdep;
previous.pc = current.ra = regs->regs[MIPS32_EF_R31];
}
while (INSTACK(current.sp, bt)) {
struct syment *symbol = NULL;
ulong offset;
if (CRASHDEBUG(8))
fprintf(fp, "level %d pc %#lx ra %#lx sp %lx\n",
level, current.pc, current.ra, current.sp);
if (!IS_KVADDR(current.pc) && !invalid_ok)
return;
symbol = value_search(current.pc, &offset);
if (!symbol && !invalid_ok) {
error(FATAL, "PC is unknown symbol (%lx)", current.pc);
return;
}
invalid_ok = 0;
/*
* If we get an address which points to the start of a
* function, then it could one of the following:
*
* - we are dealing with a noreturn function. The last call
* from a noreturn function has an an ra which points to the
* start of the function after it. This is common in the
* oops callchain because of die() which is annotated as
* noreturn.
*
* - we have taken an exception at the start of this function.
* In this case we already have the RA in current.ra.
*
* - we are in one of these routines which appear with zero
* offset in manually-constructed stack frames:
*
* * ret_from_exception
* * ret_from_irq
* * ret_from_fork
* * ret_from_kernel_thread
*/
if (!current.ra && !offset && symbol && !STRNEQ(symbol->name, "ret_from")) {
if (CRASHDEBUG(8))
fprintf(fp, "zero offset at %s, try previous symbol\n",
symbol->name);
symbol = value_search(current.pc - 4, &offset);
if (!symbol) {
error(FATAL, "PC is unknown symbol (%lx)", current.pc);
return;
}
}
if (symbol && mips_is_exception_entry(symbol)) {
struct mips_pt_regs_main *mains;
struct mips_pt_regs_cp0 *cp0;
char pt_regs[SIZE(pt_regs)];
mains = (struct mips_pt_regs_main *) \
(pt_regs + OFFSET(pt_regs_regs));
cp0 = (struct mips_pt_regs_cp0 *) \
(pt_regs + OFFSET(pt_regs_cp0_badvaddr));
GET_STACK_DATA(current.sp, pt_regs, sizeof(pt_regs));
previous.ra = mains->regs[31];
previous.sp = mains->regs[29];
current.ra = cp0->cp0_epc;
if (CRASHDEBUG(8))
fprintf(fp, "exception pc %#lx ra %#lx sp %lx\n",
previous.pc, previous.ra, previous.sp);
/* The PC causing the exception may have been invalid */
invalid_ok = 1;
} else if (symbol) {
mips_analyze_function(symbol->value, offset, ¤t, &previous);
} else {
/*
* The current PC is invalid. Assume that the code
* jumped through a invalid pointer and that the SP has
* not been adjusted.
*/
previous.sp = current.sp;
}
mips_dump_backtrace_entry(bt, symbol, ¤t, &previous, level++);
current.pc = current.ra;
current.sp = previous.sp;
current.ra = previous.ra;
if (CRASHDEBUG(8))
fprintf(fp, "next %d pc %#lx ra %#lx sp %lx\n",
level, current.pc, current.ra, current.sp);
previous.sp = previous.pc = previous.ra = 0;
}
}
static int
mips_dumpfile_stack_frame(struct bt_info *bt, ulong *nip, ulong *ksp)
{
const struct machine_specific *ms = machdep->machspec;
struct mips_regset *regs;
ulong epc, r29;
if (!ms->crash_task_regs) {
bt->flags |= BT_REGS_NOT_FOUND;
return FALSE;
}
regs = &ms->crash_task_regs[bt->tc->processor];
epc = regs->regs[MIPS32_EF_CP0_EPC];
r29 = regs->regs[MIPS32_EF_R29];
if (!epc && !r29) {
bt->flags |= BT_REGS_NOT_FOUND;
return FALSE;
}
if (nip)
*nip = epc;
if (ksp)
*ksp = r29;
bt->machdep = regs;
return TRUE;
}
static int
mips_get_frame(struct bt_info *bt, ulong *pcp, ulong *spp)
{
if (!bt->tc || !(tt->flags & THREAD_INFO))
return FALSE;
if (!readmem(bt->task + OFFSET(task_struct_thread_reg31),
KVADDR, pcp, sizeof(*pcp),
"thread_struct.regs31",
RETURN_ON_ERROR)) {
return FALSE;
}
if (!readmem(bt->task + OFFSET(task_struct_thread_reg29),
KVADDR, spp, sizeof(*spp),
"thread_struct.regs29",
RETURN_ON_ERROR)) {
return FALSE;
}
return TRUE;
}
static void
mips_stackframe_init(void)
{
long task_struct_thread = MEMBER_OFFSET("task_struct", "thread");
long thread_reg29 = MEMBER_OFFSET("thread_struct", "reg29");
long thread_reg31 = MEMBER_OFFSET("thread_struct", "reg31");
if ((task_struct_thread == INVALID_OFFSET) ||
(thread_reg29 == INVALID_OFFSET) ||
(thread_reg31 == INVALID_OFFSET)) {
error(FATAL,
"cannot determine thread_struct offsets\n");
return;
}
ASSIGN_OFFSET(task_struct_thread_reg29) =
task_struct_thread + thread_reg29;
ASSIGN_OFFSET(task_struct_thread_reg31) =
task_struct_thread + thread_reg31;
STRUCT_SIZE_INIT(pt_regs, "pt_regs");
MEMBER_OFFSET_INIT(pt_regs_regs, "pt_regs", "regs");
MEMBER_OFFSET_INIT(pt_regs_cp0_badvaddr, "pt_regs", "cp0_badvaddr");
}
static void
mips_get_stack_frame(struct bt_info *bt, ulong *pcp, ulong *spp)
{
int ret;
*pcp = 0;
*spp = 0;
bt->machdep = NULL;
if (DUMPFILE() && is_task_active(bt->task))
ret = mips_dumpfile_stack_frame(bt, pcp, spp);
else
ret = mips_get_frame(bt, pcp, spp);
if (!ret)
error(WARNING, "cannot determine starting stack frame for task %lx\n",
bt->task);
}
static int
mips_eframe_search(struct bt_info *bt)
{
return error(FATAL, "%s: not implemented\n", __func__);
}
static ulong
mips_get_task_pgd(ulong task)
{
return error(FATAL, "%s: not implemented\n", __func__);
}
static int
mips_is_task_addr(ulong task)
{
if (tt->flags & THREAD_INFO)
return IS_KVADDR(task);
return (IS_KVADDR(task) && ALIGNED_STACK_OFFSET(task) == 0);
}
static ulong
mips_processor_speed(void)
{
return 0;
}
static int
mips_get_smp_cpus(void)
{
return (get_cpus_online() > 0) ? get_cpus_online() : kt->cpus;
}
static ulong
mips_vmalloc_start(void)
{
return first_vmalloc_address();
}
/*
* Retrieve task registers for the time of the crash.
*/
static int
mips_get_crash_notes(void)
{
struct machine_specific *ms = machdep->machspec;
ulong crash_notes;
Elf32_Nhdr *note;
ulong offset;
char *buf, *p;
ulong *notes_ptrs;
ulong i;
if (!symbol_exists("crash_notes"))
return FALSE;
crash_notes = symbol_value("crash_notes");
notes_ptrs = (ulong *)GETBUF(kt->cpus*sizeof(notes_ptrs[0]));
/*
* Read crash_notes for the first CPU. crash_notes are in standard ELF
* note format.
*/
if (!readmem(crash_notes, KVADDR, ¬es_ptrs[kt->cpus-1],
sizeof(notes_ptrs[kt->cpus-1]), "crash_notes",
RETURN_ON_ERROR)) {
error(WARNING, "cannot read crash_notes\n");
FREEBUF(notes_ptrs);
return FALSE;
}
if (symbol_exists("__per_cpu_offset")) {
/* Add __per_cpu_offset for each cpu to form the pointer to the notes */
for (i = 0; i<kt->cpus; i++)
notes_ptrs[i] = notes_ptrs[kt->cpus-1] + kt->__per_cpu_offset[i];
}
buf = GETBUF(SIZE(note_buf));
if (!(panic_task_regs = calloc((size_t)kt->cpus, sizeof(*panic_task_regs))))
error(FATAL, "cannot calloc panic_task_regs space\n");
for (i=0;i<kt->cpus;i++) {
if (!readmem(notes_ptrs[i], KVADDR, buf, SIZE(note_buf), "note_buf_t",
RETURN_ON_ERROR)) {
error(WARNING, "failed to read note_buf_t\n");
goto fail;
}
/*
* Do some sanity checks for this note before reading registers from it.
*/
note = (Elf32_Nhdr *)buf;
p = buf + sizeof(Elf32_Nhdr);
/*
* dumpfiles created with qemu won't have crash_notes, but there will
* be elf notes; dumpfiles created by kdump do not create notes for
* offline cpus.
*/
if (note->n_namesz == 0 && (DISKDUMP_DUMPFILE() || KDUMP_DUMPFILE())) {
if (DISKDUMP_DUMPFILE())
note = diskdump_get_prstatus_percpu(i);
else if (KDUMP_DUMPFILE())
note = netdump_get_prstatus_percpu(i);
if (note) {
/*
* SIZE(note_buf) accounts for a "final note", which is a
* trailing empty elf note header.
*/
long notesz = SIZE(note_buf) - sizeof(Elf32_Nhdr);
if (sizeof(Elf32_Nhdr) + roundup(note->n_namesz, 4) +
note->n_descsz == notesz)
BCOPY((char *)note, buf, notesz);
} else {
error(WARNING,
"cannot find NT_PRSTATUS note for cpu: %d\n", i);
continue;
}
}
if (note->n_type != NT_PRSTATUS) {
error(WARNING, "invalid note (n_type != NT_PRSTATUS)\n");
goto fail;
}
if (p[0] != 'C' || p[1] != 'O' || p[2] != 'R' || p[3] != 'E') {
error(WARNING, "invalid note (name != \"CORE\"\n");
goto fail;
}
/*
* Find correct location of note data. This contains elf_prstatus
* structure which has registers etc. for the crashed task.
*/
offset = sizeof(Elf32_Nhdr);
offset = roundup(offset + note->n_namesz, 4);
p = buf + offset; /* start of elf_prstatus */
BCOPY(p + OFFSET(elf_prstatus_pr_reg), &panic_task_regs[i],
sizeof(panic_task_regs[i]));
}
/*
* And finally we have the registers for the crashed task. This is
* used later on when dumping backtrace.
*/
ms->crash_task_regs = panic_task_regs;
FREEBUF(buf);
FREEBUF(notes_ptrs);
return TRUE;
fail:
FREEBUF(buf);
FREEBUF(notes_ptrs);
free(panic_task_regs);
return FALSE;
}
static int mips_get_elf_notes(void)
{
struct machine_specific *ms = machdep->machspec;
int i;
if (!DISKDUMP_DUMPFILE() && !KDUMP_DUMPFILE())
return FALSE;
panic_task_regs = calloc(kt->cpus, sizeof(*panic_task_regs));
if (!panic_task_regs)
error(FATAL, "cannot calloc panic_task_regs space\n");
for (i = 0; i < kt->cpus; i++) {
Elf32_Nhdr *note = NULL;
size_t len;
if (DISKDUMP_DUMPFILE())
note = diskdump_get_prstatus_percpu(i);
else if (KDUMP_DUMPFILE())
note = netdump_get_prstatus_percpu(i);
if (!note) {
error(WARNING,
"cannot find NT_PRSTATUS note for cpu: %d\n", i);
continue;
}
len = sizeof(Elf32_Nhdr);
len = roundup(len + note->n_namesz, 4);
BCOPY((char *)note + len + OFFSET(elf_prstatus_pr_reg),
&panic_task_regs[i], sizeof(panic_task_regs[i]));
}
ms->crash_task_regs = panic_task_regs;
return TRUE;
}
static int mips_init_active_task_regs(void)
{
int retval;
retval = mips_get_crash_notes();
if (retval == TRUE)
return retval;
return mips_get_elf_notes();
}
static int
mips_verify_symbol(const char *name, ulong value, char type)
{
if (STREQ(name, "_text"))
machdep->flags |= KSYMS_START;
return (name && strlen(name) && (machdep->flags & KSYMS_START) &&
!STRNEQ(name, "__func__.") && !STRNEQ(name, "__crc_"));
}
void
mips_dump_machdep_table(ulong arg)
{
int others = 0;
fprintf(fp, " flags: %lx (", machdep->flags);
if (machdep->flags & KSYMS_START)
fprintf(fp, "%sKSYMS_START", others++ ? "|" : "");
fprintf(fp, ")\n");
fprintf(fp, " kvbase: %lx\n", machdep->kvbase);
fprintf(fp, " identity_map_base: %lx\n", machdep->identity_map_base);
fprintf(fp, " pagesize: %d\n", machdep->pagesize);
fprintf(fp, " pageshift: %d\n", machdep->pageshift);
fprintf(fp, " pagemask: %llx\n", machdep->pagemask);
fprintf(fp, " pageoffset: %lx\n", machdep->pageoffset);
fprintf(fp, " pgdir_shift: %d\n", PGDIR_SHIFT);
fprintf(fp, " ptrs_per_pgd: %lu\n", PTRS_PER_PGD);
fprintf(fp, " ptrs_per_pte: %d\n", PTRS_PER_PTE);
fprintf(fp, " stacksize: %ld\n", machdep->stacksize);