public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-08-05 16:54:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions
linux/arch/nds32/kernel/traps.c
Dmitry Safonov 18a4753f90 nds32: add show_stack_loglvl() 
Currently, the log-level of show_stack() depends on a platform
realization.  It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side.  In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages.  And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers.  Also, it will consolidate
printings with headers.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-23-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:11 -07:00

409 lines
10 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/module.h>
#include <linux/personality.h>
#include <linux/kallsyms.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/sched/task_stack.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <asm/proc-fns.h>
#include <asm/unistd.h>
#include <asm/fpu.h>
#include <linux/ptrace.h>
#include <nds32_intrinsic.h>
extern void show_pte(struct mm_struct *mm, unsigned long addr);
/*
* Dump out the contents of some memory nicely...
*/
void dump_mem(const char *lvl, unsigned long bottom, unsigned long top)
{
unsigned long first;
mm_segment_t fs;
int i;
/*
* We need to switch to kernel mode so that we can use __get_user
* to safely read from kernel space. Note that we now dump the
* code first, just in case the backtrace kills us.
*/
fs = get_fs();
set_fs(KERNEL_DS);
pr_emerg("%s(0x%08lx to 0x%08lx)\n", lvl, bottom, top);
for (first = bottom & ~31; first < top; first += 32) {
unsigned long p;
char str[sizeof(" 12345678") * 8 + 1];
memset(str, ' ', sizeof(str));
str[sizeof(str) - 1] = '\0';
for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
if (p >= bottom && p < top) {
unsigned long val;
if (__get_user(val, (unsigned long *)p) == 0)
sprintf(str + i * 9, " %08lx", val);
else
sprintf(str + i * 9, " ????????");
}
}
pr_emerg("%s%04lx:%s\n", lvl, first & 0xffff, str);
}
set_fs(fs);
}
EXPORT_SYMBOL(dump_mem);
static void dump_instr(struct pt_regs *regs)
{
unsigned long addr = instruction_pointer(regs);
mm_segment_t fs;
char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
int i;
return;
/*
* We need to switch to kernel mode so that we can use __get_user
* to safely read from kernel space. Note that we now dump the
* code first, just in case the backtrace kills us.
*/
fs = get_fs();
set_fs(KERNEL_DS);
pr_emerg("Code: ");
for (i = -4; i < 1; i++) {
unsigned int val, bad;
bad = __get_user(val, &((u32 *) addr)[i]);
if (!bad) {
p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
} else {
p += sprintf(p, "bad PC value");
break;
}
}
pr_emerg("Code: %s\n", str);
set_fs(fs);
}
#define LOOP_TIMES (100)
static void __dump(struct task_struct *tsk, unsigned long *base_reg,
const char *loglvl)
{
unsigned long ret_addr;
int cnt = LOOP_TIMES, graph = 0;
printk("%sCall Trace:\n", loglvl);
if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
while (!kstack_end(base_reg)) {
ret_addr = *base_reg++;
if (__kernel_text_address(ret_addr)) {
ret_addr = ftrace_graph_ret_addr(
tsk, &graph, ret_addr, NULL);
print_ip_sym(loglvl, ret_addr);
}
if (--cnt < 0)
break;
}
} else {
while (!kstack_end((void *)base_reg) &&
!((unsigned long)base_reg & 0x3) &&
((unsigned long)base_reg >= TASK_SIZE)) {
unsigned long next_fp;
ret_addr = base_reg[LP_OFFSET];
next_fp = base_reg[FP_OFFSET];
if (__kernel_text_address(ret_addr)) {
ret_addr = ftrace_graph_ret_addr(
tsk, &graph, ret_addr, NULL);
print_ip_sym(loglvl, ret_addr);
}
if (--cnt < 0)
break;
base_reg = (unsigned long *)next_fp;
}
}
printk("%s\n", loglvl);
}
void show_stack_loglvl(struct task_struct *tsk, unsigned long *sp,
const char *loglvl)
{
unsigned long *base_reg;
if (!tsk)
tsk = current;
if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
if (tsk != current)
base_reg = (unsigned long *)(tsk->thread.cpu_context.sp);
else
__asm__ __volatile__("\tori\t%0, $sp, #0\n":"=r"(base_reg));
} else {
if (tsk != current)
base_reg = (unsigned long *)(tsk->thread.cpu_context.fp);
else
__asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(base_reg));
}
__dump(tsk, base_reg, loglvl);
barrier();
}
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
show_stack_loglvl(tsk, sp, KERN_EMERG);
}
DEFINE_SPINLOCK(die_lock);
/*
* This function is protected against re-entrancy.
*/
void die(const char *str, struct pt_regs *regs, int err)
{
struct task_struct *tsk = current;
static int die_counter;
console_verbose();
spin_lock_irq(&die_lock);
bust_spinlocks(1);
pr_emerg("Internal error: %s: %x [#%d]\n", str, err, ++die_counter);
print_modules();
pr_emerg("CPU: %i\n", smp_processor_id());
show_regs(regs);
pr_emerg("Process %s (pid: %d, stack limit = 0x%p)\n",
tsk->comm, tsk->pid, end_of_stack(tsk));
if (!user_mode(regs) || in_interrupt()) {
dump_mem("Stack: ", regs->sp, (regs->sp + PAGE_SIZE) & PAGE_MASK);
dump_instr(regs);
dump_stack();
}
bust_spinlocks(0);
spin_unlock_irq(&die_lock);
do_exit(SIGSEGV);
}
EXPORT_SYMBOL(die);
void die_if_kernel(const char *str, struct pt_regs *regs, int err)
{
if (user_mode(regs))
return;
die(str, regs, err);
}
int bad_syscall(int n, struct pt_regs *regs)
{
if (current->personality != PER_LINUX) {
send_sig(SIGSEGV, current, 1);
return regs->uregs[0];
}
force_sig_fault(SIGILL, ILL_ILLTRP,
(void __user *)instruction_pointer(regs) - 4);
die_if_kernel("Oops - bad syscall", regs, n);
return regs->uregs[0];
}
void __pte_error(const char *file, int line, unsigned long val)
{
pr_emerg("%s:%d: bad pte %08lx.\n", file, line, val);
}
void __pmd_error(const char *file, int line, unsigned long val)
{
pr_emerg("%s:%d: bad pmd %08lx.\n", file, line, val);
}
void __pgd_error(const char *file, int line, unsigned long val)
{
pr_emerg("%s:%d: bad pgd %08lx.\n", file, line, val);
}
extern char *exception_vector, *exception_vector_end;
void __init trap_init(void)
{
return;
}
void __init early_trap_init(void)
{
unsigned long ivb = 0;
unsigned long base = PAGE_OFFSET;
memcpy((unsigned long *)base, (unsigned long *)&exception_vector,
((unsigned long)&exception_vector_end -
(unsigned long)&exception_vector));
ivb = __nds32__mfsr(NDS32_SR_IVB);
/* Check platform support. */
if (((ivb & IVB_mskNIVIC) >> IVB_offNIVIC) < 2)
panic
("IVIC mode is not allowed on the platform with interrupt controller\n");
__nds32__mtsr((ivb & ~IVB_mskESZ) | (IVB_valESZ16 << IVB_offESZ) |
IVB_BASE, NDS32_SR_IVB);
__nds32__mtsr(INT_MASK_INITAIAL_VAL, NDS32_SR_INT_MASK);
/*
* 0x800 = 128 vectors * 16byte.
* It should be enough to flush a page.
*/
cpu_cache_wbinval_page(base, true);
}
static void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
{
struct task_struct *tsk = current;
tsk->thread.trap_no = ENTRY_DEBUG_RELATED;
tsk->thread.error_code = error_code;
force_sig_fault(SIGTRAP, si_code,
(void __user *)instruction_pointer(regs));
}
void do_debug_trap(unsigned long entry, unsigned long addr,
unsigned long type, struct pt_regs *regs)
{
if (notify_die(DIE_OOPS, "Oops", regs, addr, type, SIGTRAP)
== NOTIFY_STOP)
return;
if (user_mode(regs)) {
/* trap_signal */
send_sigtrap(regs, 0, TRAP_BRKPT);
} else {
/* kernel_trap */
if (!fixup_exception(regs))
die("unexpected kernel_trap", regs, 0);
}
}
void unhandled_interruption(struct pt_regs *regs)
{
pr_emerg("unhandled_interruption\n");
show_regs(regs);
if (!user_mode(regs))
do_exit(SIGKILL);
force_sig(SIGKILL);
}
void unhandled_exceptions(unsigned long entry, unsigned long addr,
unsigned long type, struct pt_regs *regs)
{
pr_emerg("Unhandled Exception: entry: %lx addr:%lx itype:%lx\n", entry,
addr, type);
show_regs(regs);
if (!user_mode(regs))
do_exit(SIGKILL);
force_sig(SIGKILL);
}
extern int do_page_fault(unsigned long entry, unsigned long addr,
unsigned int error_code, struct pt_regs *regs);
/*
* 2:DEF dispatch for TLB MISC exception handler
*/
void do_dispatch_tlb_misc(unsigned long entry, unsigned long addr,
unsigned long type, struct pt_regs *regs)
{
type = type & (ITYPE_mskINST | ITYPE_mskETYPE);
if ((type & ITYPE_mskETYPE) < 5) {
/* Permission exceptions */
do_page_fault(entry, addr, type, regs);
} else
unhandled_exceptions(entry, addr, type, regs);
}
void do_revinsn(struct pt_regs *regs)
{
pr_emerg("Reserved Instruction\n");
show_regs(regs);
if (!user_mode(regs))
do_exit(SIGILL);
force_sig(SIGILL);
}
#ifdef CONFIG_ALIGNMENT_TRAP
extern int unalign_access_mode;
extern int do_unaligned_access(unsigned long addr, struct pt_regs *regs);
#endif
void do_dispatch_general(unsigned long entry, unsigned long addr,
unsigned long itype, struct pt_regs *regs,
unsigned long oipc)
{
unsigned int swid = itype >> ITYPE_offSWID;
unsigned long type = itype & (ITYPE_mskINST | ITYPE_mskETYPE);
if (type == ETYPE_ALIGNMENT_CHECK) {
#ifdef CONFIG_ALIGNMENT_TRAP
/* Alignment check */
if (user_mode(regs) && unalign_access_mode) {
int ret;
ret = do_unaligned_access(addr, regs);
if (ret == 0)
return;
if (ret == -EFAULT)
pr_emerg
("Unhandled unaligned access exception\n");
}
#endif
do_page_fault(entry, addr, type, regs);
} else if (type == ETYPE_RESERVED_INSTRUCTION) {
/* Reserved instruction */
do_revinsn(regs);
} else if (type == ETYPE_COPROCESSOR) {
/* Coprocessor */
#if IS_ENABLED(CONFIG_FPU)
unsigned int fucop_exist = __nds32__mfsr(NDS32_SR_FUCOP_EXIST);
unsigned int cpid = ((itype & ITYPE_mskCPID) >> ITYPE_offCPID);
if ((cpid == FPU_CPID) &&
(fucop_exist & FUCOP_EXIST_mskCP0ISFPU)) {
unsigned int subtype = (itype & ITYPE_mskSTYPE);
if (true == do_fpu_exception(subtype, regs))
return;
}
#endif
unhandled_exceptions(entry, addr, type, regs);
} else if (type == ETYPE_TRAP && swid == SWID_RAISE_INTERRUPT_LEVEL) {
/* trap, used on v3 EDM target debugging workaround */
/*
* DIPC(OIPC) is passed as parameter before
* interrupt is enabled, so the DIPC will not be corrupted
* even though interrupts are coming in
*/
/*
* 1. update ipc
* 2. update pt_regs ipc with oipc
* 3. update pt_regs ipsw (clear DEX)
*/
__asm__ volatile ("mtsr %0, $IPC\n\t"::"r" (oipc));
regs->ipc = oipc;
if (regs->pipsw & PSW_mskDEX) {
pr_emerg
("Nested Debug exception is possibly happened\n");
pr_emerg("ipc:%08x pipc:%08x\n",
(unsigned int)regs->ipc,
(unsigned int)regs->pipc);
}
do_debug_trap(entry, addr, itype, regs);
regs->ipsw &= ~PSW_mskDEX;
} else
unhandled_exceptions(entry, addr, type, regs);
}
Reference in a new issue View git blame Copy permalink