15a0015d6SChris Zankel /* 25a0015d6SChris Zankel * arch/xtensa/kernel/traps.c 35a0015d6SChris Zankel * 45a0015d6SChris Zankel * Exception handling. 55a0015d6SChris Zankel * 65a0015d6SChris Zankel * Derived from code with the following copyrights: 75a0015d6SChris Zankel * Copyright (C) 1994 - 1999 by Ralf Baechle 85a0015d6SChris Zankel * Modified for R3000 by Paul M. Antoine, 1995, 1996 95a0015d6SChris Zankel * Complete output from die() by Ulf Carlsson, 1998 105a0015d6SChris Zankel * Copyright (C) 1999 Silicon Graphics, Inc. 115a0015d6SChris Zankel * 125a0015d6SChris Zankel * Essentially rewritten for the Xtensa architecture port. 135a0015d6SChris Zankel * 143e4196a5SMax Filippov * Copyright (C) 2001 - 2013 Tensilica Inc. 155a0015d6SChris Zankel * 165a0015d6SChris Zankel * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> 175a0015d6SChris Zankel * Chris Zankel <chris@zankel.net> 185a0015d6SChris Zankel * Marc Gauthier<marc@tensilica.com, marc@alumni.uwaterloo.ca> 195a0015d6SChris Zankel * Kevin Chea 205a0015d6SChris Zankel * 215a0015d6SChris Zankel * This file is subject to the terms and conditions of the GNU General Public 225a0015d6SChris Zankel * License. See the file "COPYING" in the main directory of this archive 235a0015d6SChris Zankel * for more details. 245a0015d6SChris Zankel */ 255a0015d6SChris Zankel 265a0015d6SChris Zankel #include <linux/kernel.h> 273f07c014SIngo Molnar #include <linux/sched/signal.h> 28b17b0153SIngo Molnar #include <linux/sched/debug.h> 293f8c2452SIngo Molnar #include <linux/sched/task_stack.h> 305a0015d6SChris Zankel #include <linux/init.h> 315a0015d6SChris Zankel #include <linux/module.h> 325a0015d6SChris Zankel #include <linux/stringify.h> 335a0015d6SChris Zankel #include <linux/kallsyms.h> 345c888d53SNishanth Aravamudan #include <linux/delay.h> 355a891ed5SAlexey Dobriyan #include <linux/hardirq.h> 36c130d3beSMax Filippov #include <linux/ratelimit.h> 3765fddcfcSMike Rapoport #include <linux/pgtable.h> 385a0015d6SChris Zankel 393e4196a5SMax Filippov #include <asm/stacktrace.h> 405a0015d6SChris Zankel #include <asm/ptrace.h> 415a0015d6SChris Zankel #include <asm/timex.h> 427c0f6ba6SLinus Torvalds #include <linux/uaccess.h> 435a0015d6SChris Zankel #include <asm/processor.h> 442d6f82feSMax Filippov #include <asm/traps.h> 45c91e02bdSMax Filippov #include <asm/hw_breakpoint.h> 465a0015d6SChris Zankel 475a0015d6SChris Zankel /* 485a0015d6SChris Zankel * Machine specific interrupt handlers 495a0015d6SChris Zankel */ 505a0015d6SChris Zankel 515a0015d6SChris Zankel extern void kernel_exception(void); 525a0015d6SChris Zankel extern void user_exception(void); 535a0015d6SChris Zankel 5409f8a6dbSMax Filippov extern void fast_illegal_instruction_user(void); 555a0015d6SChris Zankel extern void fast_syscall_user(void); 565a0015d6SChris Zankel extern void fast_alloca(void); 575a0015d6SChris Zankel extern void fast_unaligned(void); 585a0015d6SChris Zankel extern void fast_second_level_miss(void); 595a0015d6SChris Zankel extern void fast_store_prohibited(void); 605a0015d6SChris Zankel extern void fast_coprocessor(void); 615a0015d6SChris Zankel 625a0015d6SChris Zankel extern void do_illegal_instruction (struct pt_regs*); 635a0015d6SChris Zankel extern void do_interrupt (struct pt_regs*); 6438fef73cSMax Filippov extern void do_nmi(struct pt_regs *); 655a0015d6SChris Zankel extern void do_unaligned_user (struct pt_regs*); 665a0015d6SChris Zankel extern void do_multihit (struct pt_regs*, unsigned long); 675a0015d6SChris Zankel extern void do_page_fault (struct pt_regs*, unsigned long); 685a0015d6SChris Zankel extern void do_debug (struct pt_regs*); 695a0015d6SChris Zankel extern void system_call (struct pt_regs*); 705a0015d6SChris Zankel 715a0015d6SChris Zankel /* 725a0015d6SChris Zankel * The vector table must be preceded by a save area (which 735a0015d6SChris Zankel * implies it must be in RAM, unless one places RAM immediately 745a0015d6SChris Zankel * before a ROM and puts the vector at the start of the ROM (!)) 755a0015d6SChris Zankel */ 765a0015d6SChris Zankel 775a0015d6SChris Zankel #define KRNL 0x01 785a0015d6SChris Zankel #define USER 0x02 795a0015d6SChris Zankel 805a0015d6SChris Zankel #define COPROCESSOR(x) \ 81173d6681SChris Zankel { EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor } 825a0015d6SChris Zankel 835a0015d6SChris Zankel typedef struct { 845a0015d6SChris Zankel int cause; 855a0015d6SChris Zankel int fast; 865a0015d6SChris Zankel void* handler; 875a0015d6SChris Zankel } dispatch_init_table_t; 885a0015d6SChris Zankel 89b91dc336SChris Zankel static dispatch_init_table_t __initdata dispatch_init_table[] = { 905a0015d6SChris Zankel 9109f8a6dbSMax Filippov #ifdef CONFIG_USER_ABI_CALL0_PROBE 9209f8a6dbSMax Filippov { EXCCAUSE_ILLEGAL_INSTRUCTION, USER, fast_illegal_instruction_user }, 9309f8a6dbSMax Filippov #endif 94173d6681SChris Zankel { EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction}, 95173d6681SChris Zankel { EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user }, 96173d6681SChris Zankel { EXCCAUSE_SYSTEM_CALL, 0, system_call }, 97173d6681SChris Zankel /* EXCCAUSE_INSTRUCTION_FETCH unhandled */ 98173d6681SChris Zankel /* EXCCAUSE_LOAD_STORE_ERROR unhandled*/ 99173d6681SChris Zankel { EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt }, 100da0a4e5cSMax Filippov #ifdef SUPPORT_WINDOWED 101173d6681SChris Zankel { EXCCAUSE_ALLOCA, USER|KRNL, fast_alloca }, 102da0a4e5cSMax Filippov #endif 103173d6681SChris Zankel /* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */ 104173d6681SChris Zankel /* EXCCAUSE_PRIVILEGED unhandled */ 1055a0015d6SChris Zankel #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION 1064ded6282SMax Filippov #ifdef CONFIG_XTENSA_UNALIGNED_USER 107173d6681SChris Zankel { EXCCAUSE_UNALIGNED, USER, fast_unaligned }, 1085a0015d6SChris Zankel #endif 1093cfc096eSMax Filippov { EXCCAUSE_UNALIGNED, 0, do_unaligned_user }, 110173d6681SChris Zankel { EXCCAUSE_UNALIGNED, KRNL, fast_unaligned }, 1115a0015d6SChris Zankel #endif 112e5083a63SJohannes Weiner #ifdef CONFIG_MMU 113173d6681SChris Zankel { EXCCAUSE_ITLB_MISS, 0, do_page_fault }, 114173d6681SChris Zankel { EXCCAUSE_ITLB_MISS, USER|KRNL, fast_second_level_miss}, 115173d6681SChris Zankel { EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit }, 116173d6681SChris Zankel { EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault }, 117173d6681SChris Zankel /* EXCCAUSE_SIZE_RESTRICTION unhandled */ 118173d6681SChris Zankel { EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault }, 119173d6681SChris Zankel { EXCCAUSE_DTLB_MISS, USER|KRNL, fast_second_level_miss}, 120173d6681SChris Zankel { EXCCAUSE_DTLB_MISS, 0, do_page_fault }, 121173d6681SChris Zankel { EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit }, 122173d6681SChris Zankel { EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault }, 123173d6681SChris Zankel /* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */ 124173d6681SChris Zankel { EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER|KRNL, fast_store_prohibited }, 125173d6681SChris Zankel { EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault }, 126173d6681SChris Zankel { EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault }, 127e5083a63SJohannes Weiner #endif /* CONFIG_MMU */ 1285a0015d6SChris Zankel /* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */ 129c658eac6SChris Zankel #if XTENSA_HAVE_COPROCESSOR(0) 1305a0015d6SChris Zankel COPROCESSOR(0), 1315a0015d6SChris Zankel #endif 132c658eac6SChris Zankel #if XTENSA_HAVE_COPROCESSOR(1) 1335a0015d6SChris Zankel COPROCESSOR(1), 1345a0015d6SChris Zankel #endif 135c658eac6SChris Zankel #if XTENSA_HAVE_COPROCESSOR(2) 1365a0015d6SChris Zankel COPROCESSOR(2), 1375a0015d6SChris Zankel #endif 138c658eac6SChris Zankel #if XTENSA_HAVE_COPROCESSOR(3) 1395a0015d6SChris Zankel COPROCESSOR(3), 1405a0015d6SChris Zankel #endif 141c658eac6SChris Zankel #if XTENSA_HAVE_COPROCESSOR(4) 1425a0015d6SChris Zankel COPROCESSOR(4), 1435a0015d6SChris Zankel #endif 144c658eac6SChris Zankel #if XTENSA_HAVE_COPROCESSOR(5) 1455a0015d6SChris Zankel COPROCESSOR(5), 1465a0015d6SChris Zankel #endif 147c658eac6SChris Zankel #if XTENSA_HAVE_COPROCESSOR(6) 1485a0015d6SChris Zankel COPROCESSOR(6), 1495a0015d6SChris Zankel #endif 150c658eac6SChris Zankel #if XTENSA_HAVE_COPROCESSOR(7) 1515a0015d6SChris Zankel COPROCESSOR(7), 1525a0015d6SChris Zankel #endif 15338fef73cSMax Filippov #if XTENSA_FAKE_NMI 15438fef73cSMax Filippov { EXCCAUSE_MAPPED_NMI, 0, do_nmi }, 15538fef73cSMax Filippov #endif 1565a0015d6SChris Zankel { EXCCAUSE_MAPPED_DEBUG, 0, do_debug }, 1575a0015d6SChris Zankel { -1, -1, 0 } 1585a0015d6SChris Zankel 1595a0015d6SChris Zankel }; 1605a0015d6SChris Zankel 1615a0015d6SChris Zankel /* The exception table <exc_table> serves two functions: 1625a0015d6SChris Zankel * 1. it contains three dispatch tables (fast_user, fast_kernel, default-c) 1635a0015d6SChris Zankel * 2. it is a temporary memory buffer for the exception handlers. 1645a0015d6SChris Zankel */ 1655a0015d6SChris Zankel 166f21a79caSMax Filippov DEFINE_PER_CPU(struct exc_table, exc_table); 1676ec7026aSMax Filippov DEFINE_PER_CPU(struct debug_table, debug_table); 1686ec7026aSMax Filippov 1695a0015d6SChris Zankel void die(const char*, struct pt_regs*, long); 1705a0015d6SChris Zankel 1715a0015d6SChris Zankel static inline void 1725a0015d6SChris Zankel __die_if_kernel(const char *str, struct pt_regs *regs, long err) 1735a0015d6SChris Zankel { 1745a0015d6SChris Zankel if (!user_mode(regs)) 1755a0015d6SChris Zankel die(str, regs, err); 1765a0015d6SChris Zankel } 1775a0015d6SChris Zankel 1785a0015d6SChris Zankel /* 1795a0015d6SChris Zankel * Unhandled Exceptions. Kill user task or panic if in kernel space. 1805a0015d6SChris Zankel */ 1815a0015d6SChris Zankel 1825a0015d6SChris Zankel void do_unhandled(struct pt_regs *regs, unsigned long exccause) 1835a0015d6SChris Zankel { 1845a0015d6SChris Zankel __die_if_kernel("Caught unhandled exception - should not happen", 1855a0015d6SChris Zankel regs, SIGKILL); 1865a0015d6SChris Zankel 1875a0015d6SChris Zankel /* If in user mode, send SIGILL signal to current process */ 188c130d3beSMax Filippov pr_info_ratelimited("Caught unhandled exception in '%s' " 1895a0015d6SChris Zankel "(pid = %d, pc = %#010lx) - should not happen\n" 1905a0015d6SChris Zankel "\tEXCCAUSE is %ld\n", 191c130d3beSMax Filippov current->comm, task_pid_nr(current), regs->pc, 192c130d3beSMax Filippov exccause); 1933cf5d076SEric W. Biederman force_sig(SIGILL); 1945a0015d6SChris Zankel } 1955a0015d6SChris Zankel 1965a0015d6SChris Zankel /* 1975a0015d6SChris Zankel * Multi-hit exception. This if fatal! 1985a0015d6SChris Zankel */ 1995a0015d6SChris Zankel 2005a0015d6SChris Zankel void do_multihit(struct pt_regs *regs, unsigned long exccause) 2015a0015d6SChris Zankel { 2025a0015d6SChris Zankel die("Caught multihit exception", regs, SIGKILL); 2035a0015d6SChris Zankel } 2045a0015d6SChris Zankel 2055a0015d6SChris Zankel /* 2062d1c645cSMarc Gauthier * IRQ handler. 2075a0015d6SChris Zankel */ 2085a0015d6SChris Zankel 2095a0015d6SChris Zankel extern void do_IRQ(int, struct pt_regs *); 2105a0015d6SChris Zankel 21138fef73cSMax Filippov #if XTENSA_FAKE_NMI 21238fef73cSMax Filippov 213e4629194SMax Filippov #define IS_POW2(v) (((v) & ((v) - 1)) == 0) 214e4629194SMax Filippov 215e4629194SMax Filippov #if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \ 216e4629194SMax Filippov IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL))) 217e4629194SMax Filippov #warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level." 218e4629194SMax Filippov #warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire." 219e4629194SMax Filippov 220e4629194SMax Filippov static inline void check_valid_nmi(void) 221e4629194SMax Filippov { 222cad6fadeSMax Filippov unsigned intread = xtensa_get_sr(interrupt); 223cad6fadeSMax Filippov unsigned intenable = xtensa_get_sr(intenable); 224e4629194SMax Filippov 225e4629194SMax Filippov BUG_ON(intread & intenable & 226e4629194SMax Filippov ~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^ 227e4629194SMax Filippov XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^ 228e4629194SMax Filippov BIT(XCHAL_PROFILING_INTERRUPT))); 229e4629194SMax Filippov } 230e4629194SMax Filippov 231e4629194SMax Filippov #else 232e4629194SMax Filippov 233e4629194SMax Filippov static inline void check_valid_nmi(void) 234e4629194SMax Filippov { 235e4629194SMax Filippov } 236e4629194SMax Filippov 237e4629194SMax Filippov #endif 238e4629194SMax Filippov 23938fef73cSMax Filippov irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id); 24038fef73cSMax Filippov 24138fef73cSMax Filippov DEFINE_PER_CPU(unsigned long, nmi_count); 24238fef73cSMax Filippov 24338fef73cSMax Filippov void do_nmi(struct pt_regs *regs) 24438fef73cSMax Filippov { 24538fef73cSMax Filippov struct pt_regs *old_regs; 24638fef73cSMax Filippov 24738fef73cSMax Filippov if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL) 24838fef73cSMax Filippov trace_hardirqs_off(); 24938fef73cSMax Filippov 25038fef73cSMax Filippov old_regs = set_irq_regs(regs); 25138fef73cSMax Filippov nmi_enter(); 25238fef73cSMax Filippov ++*this_cpu_ptr(&nmi_count); 253e4629194SMax Filippov check_valid_nmi(); 25438fef73cSMax Filippov xtensa_pmu_irq_handler(0, NULL); 25538fef73cSMax Filippov nmi_exit(); 25638fef73cSMax Filippov set_irq_regs(old_regs); 25738fef73cSMax Filippov } 25838fef73cSMax Filippov #endif 25938fef73cSMax Filippov 2605a0015d6SChris Zankel void do_interrupt(struct pt_regs *regs) 2615a0015d6SChris Zankel { 2622d1c645cSMarc Gauthier static const unsigned int_level_mask[] = { 2632d1c645cSMarc Gauthier 0, 2642d1c645cSMarc Gauthier XCHAL_INTLEVEL1_MASK, 2652d1c645cSMarc Gauthier XCHAL_INTLEVEL2_MASK, 2662d1c645cSMarc Gauthier XCHAL_INTLEVEL3_MASK, 2672d1c645cSMarc Gauthier XCHAL_INTLEVEL4_MASK, 2682d1c645cSMarc Gauthier XCHAL_INTLEVEL5_MASK, 2692d1c645cSMarc Gauthier XCHAL_INTLEVEL6_MASK, 2702d1c645cSMarc Gauthier XCHAL_INTLEVEL7_MASK, 2712d1c645cSMarc Gauthier }; 2727d5f6a9aSMax Filippov struct pt_regs *old_regs; 27343ba2237SMax Filippov unsigned unhandled = ~0u; 27499623239SMax Filippov 2757d5f6a9aSMax Filippov trace_hardirqs_off(); 2767d5f6a9aSMax Filippov 2777d5f6a9aSMax Filippov old_regs = set_irq_regs(regs); 27899623239SMax Filippov irq_enter(); 2792d1c645cSMarc Gauthier 2802d1c645cSMarc Gauthier for (;;) { 281cad6fadeSMax Filippov unsigned intread = xtensa_get_sr(interrupt); 282cad6fadeSMax Filippov unsigned intenable = xtensa_get_sr(intenable); 283895666a9SMax Filippov unsigned int_at_level = intread & intenable; 284895666a9SMax Filippov unsigned level; 2852d1c645cSMarc Gauthier 286895666a9SMax Filippov for (level = LOCKLEVEL; level > 0; --level) { 287895666a9SMax Filippov if (int_at_level & int_level_mask[level]) { 288895666a9SMax Filippov int_at_level &= int_level_mask[level]; 28943ba2237SMax Filippov if (int_at_level & unhandled) 29043ba2237SMax Filippov int_at_level &= unhandled; 29143ba2237SMax Filippov else 29243ba2237SMax Filippov unhandled |= int_level_mask[level]; 293895666a9SMax Filippov break; 294895666a9SMax Filippov } 295895666a9SMax Filippov } 296895666a9SMax Filippov 297895666a9SMax Filippov if (level == 0) 29899623239SMax Filippov break; 2992d1c645cSMarc Gauthier 30043ba2237SMax Filippov /* clear lowest pending irq in the unhandled mask */ 30143ba2237SMax Filippov unhandled ^= (int_at_level & -int_at_level); 30299623239SMax Filippov do_IRQ(__ffs(int_at_level), regs); 30399623239SMax Filippov } 3045a0015d6SChris Zankel 30599623239SMax Filippov irq_exit(); 30699623239SMax Filippov set_irq_regs(old_regs); 3075a0015d6SChris Zankel } 3085a0015d6SChris Zankel 3095a0015d6SChris Zankel /* 3105a0015d6SChris Zankel * Illegal instruction. Fatal if in kernel space. 3115a0015d6SChris Zankel */ 3125a0015d6SChris Zankel 3135a0015d6SChris Zankel void 3145a0015d6SChris Zankel do_illegal_instruction(struct pt_regs *regs) 3155a0015d6SChris Zankel { 3165a0015d6SChris Zankel __die_if_kernel("Illegal instruction in kernel", regs, SIGKILL); 3175a0015d6SChris Zankel 3185a0015d6SChris Zankel /* If in user mode, send SIGILL signal to current process. */ 3195a0015d6SChris Zankel 320c130d3beSMax Filippov pr_info_ratelimited("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n", 32119c5870cSAlexey Dobriyan current->comm, task_pid_nr(current), regs->pc); 3223cf5d076SEric W. Biederman force_sig(SIGILL); 3235a0015d6SChris Zankel } 3245a0015d6SChris Zankel 3255a0015d6SChris Zankel 3265a0015d6SChris Zankel /* 3275a0015d6SChris Zankel * Handle unaligned memory accesses from user space. Kill task. 3285a0015d6SChris Zankel * 3295a0015d6SChris Zankel * If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory 3305a0015d6SChris Zankel * accesses causes from user space. 3315a0015d6SChris Zankel */ 3325a0015d6SChris Zankel 3335a0015d6SChris Zankel #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION 3345a0015d6SChris Zankel void 3355a0015d6SChris Zankel do_unaligned_user (struct pt_regs *regs) 3365a0015d6SChris Zankel { 3375a0015d6SChris Zankel __die_if_kernel("Unhandled unaligned exception in kernel", 3385a0015d6SChris Zankel regs, SIGKILL); 3395a0015d6SChris Zankel 3405a0015d6SChris Zankel current->thread.bad_vaddr = regs->excvaddr; 3415a0015d6SChris Zankel current->thread.error_code = -3; 342c130d3beSMax Filippov pr_info_ratelimited("Unaligned memory access to %08lx in '%s' " 3435a0015d6SChris Zankel "(pid = %d, pc = %#010lx)\n", 344c130d3beSMax Filippov regs->excvaddr, current->comm, 345c130d3beSMax Filippov task_pid_nr(current), regs->pc); 3462e1661d2SEric W. Biederman force_sig_fault(SIGBUS, BUS_ADRALN, (void *) regs->excvaddr); 3475a0015d6SChris Zankel } 3485a0015d6SChris Zankel #endif 3495a0015d6SChris Zankel 350c91e02bdSMax Filippov /* Handle debug events. 351c91e02bdSMax Filippov * When CONFIG_HAVE_HW_BREAKPOINT is on this handler is called with 352c91e02bdSMax Filippov * preemption disabled to avoid rescheduling and keep mapping of hardware 353c91e02bdSMax Filippov * breakpoint structures to debug registers intact, so that 354c91e02bdSMax Filippov * DEBUGCAUSE.DBNUM could be used in case of data breakpoint hit. 355c91e02bdSMax Filippov */ 3565a0015d6SChris Zankel void 3575a0015d6SChris Zankel do_debug(struct pt_regs *regs) 3585a0015d6SChris Zankel { 359c91e02bdSMax Filippov #ifdef CONFIG_HAVE_HW_BREAKPOINT 360c91e02bdSMax Filippov int ret = check_hw_breakpoint(regs); 361c91e02bdSMax Filippov 362c91e02bdSMax Filippov preempt_enable(); 363c91e02bdSMax Filippov if (ret == 0) 364c91e02bdSMax Filippov return; 365c91e02bdSMax Filippov #endif 3665a0015d6SChris Zankel __die_if_kernel("Breakpoint in kernel", regs, SIGKILL); 3675a0015d6SChris Zankel 3685a0015d6SChris Zankel /* If in user mode, send SIGTRAP signal to current process */ 3695a0015d6SChris Zankel 3703cf5d076SEric W. Biederman force_sig(SIGTRAP); 3715a0015d6SChris Zankel } 3725a0015d6SChris Zankel 3735a0015d6SChris Zankel 374f21a79caSMax Filippov #define set_handler(type, cause, handler) \ 375f21a79caSMax Filippov do { \ 376f21a79caSMax Filippov unsigned int cpu; \ 377f21a79caSMax Filippov \ 378f21a79caSMax Filippov for_each_possible_cpu(cpu) \ 379f21a79caSMax Filippov per_cpu(exc_table, cpu).type[cause] = (handler);\ 380f21a79caSMax Filippov } while (0) 381f615136cSMax Filippov 38228570e8dSMax Filippov /* Set exception C handler - for temporary use when probing exceptions */ 38328570e8dSMax Filippov 38428570e8dSMax Filippov void * __init trap_set_handler(int cause, void *handler) 38528570e8dSMax Filippov { 386f21a79caSMax Filippov void *previous = per_cpu(exc_table, 0).default_handler[cause]; 387f21a79caSMax Filippov 388f21a79caSMax Filippov set_handler(default_handler, cause, handler); 38928570e8dSMax Filippov return previous; 39028570e8dSMax Filippov } 39128570e8dSMax Filippov 39228570e8dSMax Filippov 39349b424feSMax Filippov static void trap_init_excsave(void) 394f615136cSMax Filippov { 395f21a79caSMax Filippov unsigned long excsave1 = (unsigned long)this_cpu_ptr(&exc_table); 396f615136cSMax Filippov __asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1)); 397f615136cSMax Filippov } 398f615136cSMax Filippov 3996ec7026aSMax Filippov static void trap_init_debug(void) 4006ec7026aSMax Filippov { 4016ec7026aSMax Filippov unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table); 4026ec7026aSMax Filippov 4036ec7026aSMax Filippov this_cpu_ptr(&debug_table)->debug_exception = debug_exception; 4046ec7026aSMax Filippov __asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL) 4056ec7026aSMax Filippov :: "a"(debugsave)); 4066ec7026aSMax Filippov } 4076ec7026aSMax Filippov 4085a0015d6SChris Zankel /* 4095a0015d6SChris Zankel * Initialize dispatch tables. 4105a0015d6SChris Zankel * 4115a0015d6SChris Zankel * The exception vectors are stored compressed the __init section in the 4125a0015d6SChris Zankel * dispatch_init_table. This function initializes the following three tables 4135a0015d6SChris Zankel * from that compressed table: 4145a0015d6SChris Zankel * - fast user first dispatch table for user exceptions 4155a0015d6SChris Zankel * - fast kernel first dispatch table for kernel exceptions 4165a0015d6SChris Zankel * - default C-handler C-handler called by the default fast handler. 4175a0015d6SChris Zankel * 4185a0015d6SChris Zankel * See vectors.S for more details. 4195a0015d6SChris Zankel */ 4205a0015d6SChris Zankel 421b91dc336SChris Zankel void __init trap_init(void) 4225a0015d6SChris Zankel { 4235a0015d6SChris Zankel int i; 4245a0015d6SChris Zankel 4255a0015d6SChris Zankel /* Setup default vectors. */ 4265a0015d6SChris Zankel 427f21a79caSMax Filippov for (i = 0; i < EXCCAUSE_N; i++) { 428f21a79caSMax Filippov set_handler(fast_user_handler, i, user_exception); 429f21a79caSMax Filippov set_handler(fast_kernel_handler, i, kernel_exception); 430f21a79caSMax Filippov set_handler(default_handler, i, do_unhandled); 4315a0015d6SChris Zankel } 4325a0015d6SChris Zankel 4335a0015d6SChris Zankel /* Setup specific handlers. */ 4345a0015d6SChris Zankel 4355a0015d6SChris Zankel for(i = 0; dispatch_init_table[i].cause >= 0; i++) { 4365a0015d6SChris Zankel int fast = dispatch_init_table[i].fast; 4375a0015d6SChris Zankel int cause = dispatch_init_table[i].cause; 4385a0015d6SChris Zankel void *handler = dispatch_init_table[i].handler; 4395a0015d6SChris Zankel 4405a0015d6SChris Zankel if (fast == 0) 441f21a79caSMax Filippov set_handler(default_handler, cause, handler); 44260deebe6SMax Filippov if ((fast & USER) != 0) 443f21a79caSMax Filippov set_handler(fast_user_handler, cause, handler); 44460deebe6SMax Filippov if ((fast & KRNL) != 0) 445f21a79caSMax Filippov set_handler(fast_kernel_handler, cause, handler); 4465a0015d6SChris Zankel } 4475a0015d6SChris Zankel 4485a0015d6SChris Zankel /* Initialize EXCSAVE_1 to hold the address of the exception table. */ 449f615136cSMax Filippov trap_init_excsave(); 4506ec7026aSMax Filippov trap_init_debug(); 4515a0015d6SChris Zankel } 4525a0015d6SChris Zankel 453f615136cSMax Filippov #ifdef CONFIG_SMP 45449b424feSMax Filippov void secondary_trap_init(void) 455f615136cSMax Filippov { 456f615136cSMax Filippov trap_init_excsave(); 4576ec7026aSMax Filippov trap_init_debug(); 458f615136cSMax Filippov } 459f615136cSMax Filippov #endif 460f615136cSMax Filippov 4615a0015d6SChris Zankel /* 4625a0015d6SChris Zankel * This function dumps the current valid window frame and other base registers. 4635a0015d6SChris Zankel */ 4645a0015d6SChris Zankel 4655a0015d6SChris Zankel void show_regs(struct pt_regs * regs) 4665a0015d6SChris Zankel { 467431d1a34SMax Filippov int i; 4685a0015d6SChris Zankel 469a43cb95dSTejun Heo show_regs_print_info(KERN_DEFAULT); 470a43cb95dSTejun Heo 4718d7e8240SChris Zankel for (i = 0; i < 16; i++) { 4725a0015d6SChris Zankel if ((i % 8) == 0) 473d4eccafcSMax Filippov pr_info("a%02d:", i); 474d4eccafcSMax Filippov pr_cont(" %08lx", regs->areg[i]); 4755a0015d6SChris Zankel } 476d4eccafcSMax Filippov pr_cont("\n"); 477d4eccafcSMax Filippov pr_info("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n", 4785a0015d6SChris Zankel regs->pc, regs->ps, regs->depc, regs->excvaddr); 479d4eccafcSMax Filippov pr_info("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n", 4805a0015d6SChris Zankel regs->lbeg, regs->lend, regs->lcount, regs->sar); 4815a0015d6SChris Zankel if (user_mode(regs)) 482d4eccafcSMax Filippov pr_cont("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n", 4835a0015d6SChris Zankel regs->windowbase, regs->windowstart, regs->wmask, 4845a0015d6SChris Zankel regs->syscall); 4855a0015d6SChris Zankel } 4865a0015d6SChris Zankel 4873e4196a5SMax Filippov static int show_trace_cb(struct stackframe *frame, void *data) 488586411dcSJohannes Weiner { 48947fb7029SDmitry Safonov const char *loglvl = data; 49047fb7029SDmitry Safonov 491e640cc30SMax Filippov if (kernel_text_address(frame->pc)) 49247fb7029SDmitry Safonov printk("%s [<%08lx>] %pB\n", 49347fb7029SDmitry Safonov loglvl, frame->pc, (void *)frame->pc); 4943e4196a5SMax Filippov return 0; 495586411dcSJohannes Weiner } 496586411dcSJohannes Weiner 49747fb7029SDmitry Safonov static void show_trace(struct task_struct *task, unsigned long *sp, 49847fb7029SDmitry Safonov const char *loglvl) 4995a0015d6SChris Zankel { 5003e4196a5SMax Filippov if (!sp) 5013e4196a5SMax Filippov sp = stack_pointer(task); 5025a0015d6SChris Zankel 50347fb7029SDmitry Safonov printk("%sCall Trace:\n", loglvl); 50447fb7029SDmitry Safonov walk_stackframe(sp, show_trace_cb, (void *)loglvl); 5055a0015d6SChris Zankel } 5065a0015d6SChris Zankel 507c5fccebcSMax Filippov #define STACK_DUMP_ENTRY_SIZE 4 508c5fccebcSMax Filippov #define STACK_DUMP_LINE_SIZE 32 5098951eb15SMax Filippov static size_t kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; 5105a0015d6SChris Zankel 5119cb8f069SDmitry Safonov void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl) 5125a0015d6SChris Zankel { 513c5fccebcSMax Filippov size_t len; 5145a0015d6SChris Zankel 51528a0ce7fSJohannes Weiner if (!sp) 516586411dcSJohannes Weiner sp = stack_pointer(task); 517c5fccebcSMax Filippov 518c5fccebcSMax Filippov len = min((-(size_t)sp) & (THREAD_SIZE - STACK_DUMP_ENTRY_SIZE), 519c5fccebcSMax Filippov kstack_depth_to_print * STACK_DUMP_ENTRY_SIZE); 5205a0015d6SChris Zankel 52120da1e8bSDmitry Safonov printk("%sStack:\n", loglvl); 52220da1e8bSDmitry Safonov print_hex_dump(loglvl, " ", DUMP_PREFIX_NONE, 523c5fccebcSMax Filippov STACK_DUMP_LINE_SIZE, STACK_DUMP_ENTRY_SIZE, 524c5fccebcSMax Filippov sp, len, false); 52520da1e8bSDmitry Safonov show_trace(task, sp, loglvl); 52620da1e8bSDmitry Safonov } 52720da1e8bSDmitry Safonov 52834af946aSIngo Molnar DEFINE_SPINLOCK(die_lock); 5295a0015d6SChris Zankel 5309fd5a04dSEric W. Biederman void __noreturn die(const char * str, struct pt_regs * regs, long err) 5315a0015d6SChris Zankel { 5325a0015d6SChris Zankel static int die_counter; 5336c5260d7SThomas Gleixner const char *pr = ""; 5346c5260d7SThomas Gleixner 5356c5260d7SThomas Gleixner if (IS_ENABLED(CONFIG_PREEMPTION)) 5366c5260d7SThomas Gleixner pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT"; 5375a0015d6SChris Zankel 5385a0015d6SChris Zankel console_verbose(); 5395a0015d6SChris Zankel spin_lock_irq(&die_lock); 5405a0015d6SChris Zankel 5416c5260d7SThomas Gleixner pr_info("%s: sig: %ld [#%d]%s\n", str, err, ++die_counter, pr); 5425a0015d6SChris Zankel show_regs(regs); 5435a0015d6SChris Zankel if (!user_mode(regs)) 5449cb8f069SDmitry Safonov show_stack(NULL, (unsigned long *)regs->areg[1], KERN_INFO); 5455a0015d6SChris Zankel 546373d4d09SRusty Russell add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 5475a0015d6SChris Zankel spin_unlock_irq(&die_lock); 5485a0015d6SChris Zankel 5495a0015d6SChris Zankel if (in_interrupt()) 5505a0015d6SChris Zankel panic("Fatal exception in interrupt"); 5515a0015d6SChris Zankel 552cea6a4baSHorms if (panic_on_oops) 553012c437dSHorms panic("Fatal exception"); 554cea6a4baSHorms 555*0e25498fSEric W. Biederman make_task_dead(err); 5565a0015d6SChris Zankel } 557