// SPDX-License-Identifier: GPL-2.0
/*
* arch/sparc/kernel/traps.c
*
* Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
* Copyright 2000 Jakub Jelinek (jakub@redhat.com)
*/
/*
* I hate traps on the sparc, grrr...
*/
#include <linux/sched/mm.h>
#include <linux/sched/debug.h>
#include <linux/mm_types.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/kdebug.h>
#include <linux/export.h>
#include <linux/pgtable.h>
#include <asm/delay.h>
#include <asm/ptrace.h>
#include <asm/oplib.h>
#include <asm/page.h>
#include <asm/unistd.h>
#include <asm/traps.h>
#include "entry.h"
#include "kernel.h"
/* #define TRAP_DEBUG */
static void instruction_dump(unsigned long *pc)
{
int i;
if((((unsigned long) pc) & 3))
return;
for(i = -3; i < 6; i++)
printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
printk("\n");
}
#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
void __noreturn die_if_kernel(char *str, struct pt_regs *regs)
{
static int die_counter;
int count = 0;
/* Amuse the user. */
printk(
" \\|/ ____ \\|/\n"
" \"@'/ ,. \\`@\"\n"
" /_| \\__/ |_\\\n"
" \\__U_/\n");
printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
show_regs(regs);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
__SAVE; __SAVE; __SAVE; __SAVE;
__SAVE; __SAVE; __SAVE; __SAVE;
__RESTORE; __RESTORE; __RESTORE; __RESTORE;
__RESTORE; __RESTORE; __RESTORE; __RESTORE;
{
struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];
/* Stop the back trace when we hit userland or we
* find some badly aligned kernel stack. Set an upper
* bound in case our stack is trashed and we loop.
*/
while(rw &&
count++ < 30 &&
(((unsigned long) rw) >= PAGE_OFFSET) &&
!(((unsigned long) rw) & 0x7)) {
printk("Caller[%08lx]: %pS\n", rw->ins[7],
(void *) rw->ins[7]);
rw = (struct reg_window32 *)rw->ins[6];
}
}
printk("Instruction DUMP:");
instruction_dump ((unsigned long *) regs->pc);
make_task_dead((regs->psr & PSR_PS) ? SIGKILL : SIGSEGV);
}
void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
{
if(type < 0x80) {
/* Sun OS's puke from bad traps, Linux survives! */
printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
die_if_kernel("Whee... Hello Mr. Penguin", regs);
}
if(regs->psr & PSR_PS)
die_if_kernel("Kernel bad trap", regs);
force_sig_fault_trapno(SIGILL, ILL_ILLTRP,
(void __user *)regs->pc, type - 0x80);
}
void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
if(psr & PSR_PS)
die_if_kernel("Kernel illegal instruction", regs);
#ifdef TRAP_DEBUG
printk("Ill instr. at pc=%08lx instruction is %08lx\n",
regs->pc, *(unsigned long *)regs->pc);
#endif
send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, current);
}
void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
if(psr & PSR_PS)
die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, current);
}
/* XXX User may want to be allowed to do this. XXX */
void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
if(regs->psr & PSR_PS) {
printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
regs->u_regs[UREG_RETPC]);
die_if_kernel("BOGUS", regs);
/* die_if_kernel("Kernel MNA access", regs); */
}
#if 0
show_regs (regs);
instruction_dump ((unsigned long *) regs->pc);
printk ("do_MNA!\n");
#endif
send_sig_fault(SIGBUS, BUS_ADRALN,
/* FIXME: Should dig out mna address */ (void *)0,
current);
}
static unsigned long init_fsr = 0x0UL;
static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
{ ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
/* Sanity check... */
if(psr & PSR_PS)
die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
put_psr(get_psr() | PSR_EF); /* Allow FPU ops. */
regs->psr |= PSR_EF;
#ifndef CONFIG_SMP
if(last_task_used_math == current)
return;
if(last_task_used_math) {
/* Other processes fpu state, save away */
struct task_struct *fptask = last_task_used_math;
fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
&fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
}
last_task_used_math = current;
if(used_math()) {
fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
} else {
/* Set initial sane state. */
fpload(&init_fregs[0], &init_fsr);
set_used_math();
}
#else
if(!used_math()) {
fpload(&init_fregs[0], &init_fsr);
set_used_math();
} else {
fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
}
set_thread_flag(TIF_USEDFPU);
#endif
}
static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
static unsigned long fake_fsr;
static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
static unsigned long fake_depth;
void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
static int calls;
unsigned long fsr;
int ret = 0;
int code;
#ifndef CONFIG_SMP
struct task_struct *fpt = last_task_used_math;
#else
struct task_struct *fpt = current;
#endif
put_psr(get_psr() | PSR_EF);
/* If nobody owns the fpu right now, just clear the
* error into our fake static buffer and hope it don't
* happen again. Thank you crashme...
*/
#ifndef CONFIG_SMP
if(!fpt) {
#else
if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
#endif
fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
regs->psr &= ~PSR_EF;
return;
}
fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
&fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
#ifdef DEBUG_FPU
printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
#endif
switch ((fpt->thread.fsr & 0x1c000)) {
/* switch on the contents of the ftt [floating point trap type] field */
#ifdef DEBUG_FPU
case (1 << 14):
printk("IEEE_754_exception\n");
break;
#endif
case (2 << 14): /* unfinished_FPop (underflow & co) */
case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */
ret = do_mathemu(regs, fpt);
break;
#ifdef DEBUG_FPU
case (4 << 14):
printk("sequence_error (OS bug...)\n");
break;
case (5 << 14):
printk("hardware_error (uhoh!)\n");
break;
case (6 << 14):
printk("invalid_fp_register (user error)\n");
break;
#endif /* DEBUG_FPU */
}
/* If we successfully emulated the FPop, we pretend the trap never happened :-> */
if (ret) {
fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
return;
}
/* nope, better SIGFPE the offending process... */
#ifdef CONFIG_SMP
clear_tsk_thread_flag(fpt, TIF_USEDFPU);
#endif
if(psr & PSR_PS) {
/* The first fsr store/load we tried trapped,
* the second one will not (we hope).
*/
printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
regs->pc);
regs->pc = regs->npc;
regs->npc += 4;
calls++;
if(calls > 2)
die_if_kernel("Too many Penguin-FPU traps from kernel mode",
regs);
return;
}
fsr = fpt->thread.fsr;
code = FPE_FLTUNK;
if ((fsr & 0x1c000) == (1 << 14)) {
if (fsr & 0x10)
code = FPE_FLTINV;
else if (fsr & 0x08)
code = FPE_FLTOVF;
else if (fsr & 0x04)
code = FPE_FLTUND;
else if (fsr & 0x02)
code = FPE_FLTDIV;
else if (fsr & 0x01)
code = FPE_FLTRES;
}
send_sig_fault(SIGFPE, code, (void __user *)pc, fpt);
#ifndef CONFIG_SMP
last_task_used_math = NULL;
#endif
regs->psr &= ~PSR_EF;
if(calls > 0)
calls=0;
}
void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
if(psr & PSR_PS)
die_if_kernel("Penguin overflow trap from kernel mode", regs);
send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, current);
}
void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
#ifdef TRAP_DEBUG
printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
pc, npc, psr);
#endif
if(psr & PSR_PS)
panic("Tell me what a watchpoint trap is, and I'll then deal "
"with such a beast...");
}
void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
#ifdef TRAP_DEBUG
printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
pc, npc, psr);
#endif
force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc);
}
void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
}
void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
#ifdef TRAP_DEBUG
printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
pc, npc, psr);
#endif
send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
}
void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, current);
}
#ifdef CONFIG_DEBUG_BUGVERBOSE
void do_BUG(const char *file, int line)
{
// bust_spinlocks(1); XXX Not in our original BUG()
printk("kernel BUG at %s:%d!\n", file, line);
}
EXPORT_SYMBOL(do_BUG);
#endif
/* Since we have our mappings set up, on multiprocessors we can spin them
* up here so that timer interrupts work during initialization.
*/
void trap_init(void)
{
extern void thread_info_offsets_are_bolixed_pete(void);
/* Force linker to barf if mismatched */
if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) ||
TI_TASK != offsetof(struct thread_info, task) ||
TI_FLAGS != offsetof(struct thread_info, flags) ||
TI_CPU != offsetof(struct thread_info, cpu) ||
TI_PREEMPT != offsetof(struct thread_info, preempt_count) ||
TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) ||
TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) ||
TI_KSP != offsetof(struct thread_info, ksp) ||
TI_KPC != offsetof(struct thread_info, kpc) ||
TI_KPSR != offsetof(struct thread_info, kpsr) ||
TI_KWIM != offsetof(struct thread_info, kwim) ||
TI_REG_WINDOW != offsetof(struct thread_info, reg_window) ||
TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) ||
TI_W_SAVED != offsetof(struct thread_info, w_saved))
thread_info_offsets_are_bolixed_pete();
/* Attach to the address space of init_task. */
mmgrab(&init_mm);
current->active_mm = &init_mm;
/* NOTE: Other cpus have this done as they are started
* up on SMP.
*/
}