diff options
Diffstat (limited to 'arch/s390/kernel/traps.c')
-rw-r--r-- | arch/s390/kernel/traps.c | 200 |
1 files changed, 177 insertions, 23 deletions
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index 164c0282b41a..46dac4540ca8 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -13,8 +13,11 @@ * 'Traps.c' handles hardware traps and faults after we have saved some * state in 'asm.s'. */ +#include "asm/irqflags.h" +#include "asm/ptrace.h" #include <linux/kprobes.h> #include <linux/kdebug.h> +#include <linux/randomize_kstack.h> #include <linux/extable.h> #include <linux/ptrace.h> #include <linux/sched.h> @@ -23,7 +26,10 @@ #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/cpu.h> +#include <linux/entry-common.h> +#include <asm/asm-extable.h> #include <asm/fpu/api.h> +#include <asm/vtime.h> #include "entry.h" static inline void __user *get_trap_ip(struct pt_regs *regs) @@ -31,16 +37,18 @@ static inline void __user *get_trap_ip(struct pt_regs *regs) unsigned long address; if (regs->int_code & 0x200) - address = *(unsigned long *)(current->thread.trap_tdb + 24); + address = current->thread.trap_tdb.data[3]; else address = regs->psw.addr; return (void __user *) (address - (regs->int_code >> 16)); } +#ifdef CONFIG_GENERIC_BUG int is_valid_bugaddr(unsigned long addr) { return 1; } +#endif void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str) { @@ -48,18 +56,8 @@ void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str) force_sig_fault(si_signo, si_code, get_trap_ip(regs)); report_user_fault(regs, si_signo, 0); } else { - const struct exception_table_entry *fixup; - fixup = s390_search_extables(regs->psw.addr); - if (fixup) - regs->psw.addr = extable_fixup(fixup); - else { - enum bug_trap_type btt; - - btt = report_bug(regs->psw.addr, regs); - if (btt == BUG_TRAP_TYPE_WARN) - return; + if (!fixup_exception(regs)) die(regs, str); - } } } @@ -83,17 +81,17 @@ void do_per_trap(struct pt_regs *regs) } NOKPROBE_SYMBOL(do_per_trap); -void default_trap_handler(struct pt_regs *regs) +static void default_trap_handler(struct pt_regs *regs) { if (user_mode(regs)) { report_user_fault(regs, SIGSEGV, 0); - do_exit(SIGSEGV); + force_exit_sig(SIGSEGV); } else die(regs, "Unknown program exception"); } #define DO_ERROR_INFO(name, signr, sicode, str) \ -void name(struct pt_regs *regs) \ +static void name(struct pt_regs *regs) \ { \ do_trap(regs, signr, sicode, str); \ } @@ -145,13 +143,13 @@ static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc) do_trap(regs, SIGFPE, si_code, "floating point exception"); } -void translation_exception(struct pt_regs *regs) +static void translation_specification_exception(struct pt_regs *regs) { /* May never happen. */ - panic("Translation exception"); + panic("Translation-Specification Exception"); } -void illegal_op(struct pt_regs *regs) +static void illegal_op(struct pt_regs *regs) { __u8 opcode[6]; __u16 __user *location; @@ -193,11 +191,11 @@ NOKPROBE_SYMBOL(illegal_op); DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN, "specification exception"); -void vector_exception(struct pt_regs *regs) +static void vector_exception(struct pt_regs *regs) { int si_code, vic; - if (!MACHINE_HAS_VX) { + if (!cpu_has_vx()) { do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation"); return; } @@ -227,7 +225,7 @@ void vector_exception(struct pt_regs *regs) do_trap(regs, SIGFPE, si_code, "vector exception"); } -void data_exception(struct pt_regs *regs) +static void data_exception(struct pt_regs *regs) { save_fpu_regs(); if (current->thread.fpu.fpc & FPC_DXC_MASK) @@ -236,7 +234,7 @@ void data_exception(struct pt_regs *regs) do_trap(regs, SIGILL, ILL_ILLOPN, "data exception"); } -void space_switch_exception(struct pt_regs *regs) +static void space_switch_exception(struct pt_regs *regs) { /* Set user psw back to home space mode. */ if (user_mode(regs)) @@ -245,6 +243,23 @@ void space_switch_exception(struct pt_regs *regs) do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event"); } +static void monitor_event_exception(struct pt_regs *regs) +{ + if (user_mode(regs)) + return; + + switch (report_bug(regs->psw.addr - (regs->int_code >> 16), regs)) { + case BUG_TRAP_TYPE_NONE: + fixup_exception(regs); + break; + case BUG_TRAP_TYPE_WARN: + break; + case BUG_TRAP_TYPE_BUG: + die(regs, "monitor event"); + break; + } +} + void kernel_stack_overflow(struct pt_regs *regs) { bust_spinlocks(1); @@ -255,8 +270,147 @@ void kernel_stack_overflow(struct pt_regs *regs) } NOKPROBE_SYMBOL(kernel_stack_overflow); +static void __init test_monitor_call(void) +{ + int val = 1; + + if (!IS_ENABLED(CONFIG_BUG)) + return; + asm volatile( + " mc 0,0\n" + "0: xgr %0,%0\n" + "1:\n" + EX_TABLE(0b,1b) + : "+d" (val)); + if (!val) + panic("Monitor call doesn't work!\n"); +} + void __init trap_init(void) { - sort_extable(__start_dma_ex_table, __stop_dma_ex_table); + unsigned long flags; + struct ctlreg cr0; + + local_irq_save(flags); + cr0 = local_ctl_clear_bit(0, CR0_LOW_ADDRESS_PROTECTION_BIT); + psw_bits(S390_lowcore.external_new_psw).mcheck = 1; + psw_bits(S390_lowcore.program_new_psw).mcheck = 1; + psw_bits(S390_lowcore.svc_new_psw).mcheck = 1; + psw_bits(S390_lowcore.io_new_psw).mcheck = 1; + local_ctl_load(0, &cr0); + local_irq_restore(flags); local_mcck_enable(); + test_monitor_call(); } + +static void (*pgm_check_table[128])(struct pt_regs *regs); + +void noinstr __do_pgm_check(struct pt_regs *regs) +{ + unsigned int trapnr; + irqentry_state_t state; + + regs->int_code = S390_lowcore.pgm_int_code; + regs->int_parm_long = S390_lowcore.trans_exc_code; + + state = irqentry_enter(regs); + + if (user_mode(regs)) { + update_timer_sys(); + if (!static_branch_likely(&cpu_has_bear)) { + if (regs->last_break < 4096) + regs->last_break = 1; + } + current->thread.last_break = regs->last_break; + } + + if (S390_lowcore.pgm_code & 0x0200) { + /* transaction abort */ + current->thread.trap_tdb = S390_lowcore.pgm_tdb; + } + + if (S390_lowcore.pgm_code & PGM_INT_CODE_PER) { + if (user_mode(regs)) { + struct per_event *ev = ¤t->thread.per_event; + + set_thread_flag(TIF_PER_TRAP); + ev->address = S390_lowcore.per_address; + ev->cause = S390_lowcore.per_code_combined; + ev->paid = S390_lowcore.per_access_id; + } else { + /* PER event in kernel is kprobes */ + __arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER); + do_per_trap(regs); + goto out; + } + } + + if (!irqs_disabled_flags(regs->psw.mask)) + trace_hardirqs_on(); + __arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER); + + trapnr = regs->int_code & PGM_INT_CODE_MASK; + if (trapnr) + pgm_check_table[trapnr](regs); +out: + local_irq_disable(); + irqentry_exit(regs, state); +} + +/* + * The program check table contains exactly 128 (0x00-0x7f) entries. Each + * line defines the function to be called corresponding to the program check + * interruption code. + */ +static void (*pgm_check_table[128])(struct pt_regs *regs) = { + [0x00] = default_trap_handler, + [0x01] = illegal_op, + [0x02] = privileged_op, + [0x03] = execute_exception, + [0x04] = do_protection_exception, + [0x05] = addressing_exception, + [0x06] = specification_exception, + [0x07] = data_exception, + [0x08] = overflow_exception, + [0x09] = divide_exception, + [0x0a] = overflow_exception, + [0x0b] = divide_exception, + [0x0c] = hfp_overflow_exception, + [0x0d] = hfp_underflow_exception, + [0x0e] = hfp_significance_exception, + [0x0f] = hfp_divide_exception, + [0x10] = do_dat_exception, + [0x11] = do_dat_exception, + [0x12] = translation_specification_exception, + [0x13] = special_op_exception, + [0x14] = default_trap_handler, + [0x15] = operand_exception, + [0x16] = default_trap_handler, + [0x17] = default_trap_handler, + [0x18] = transaction_exception, + [0x19] = default_trap_handler, + [0x1a] = default_trap_handler, + [0x1b] = vector_exception, + [0x1c] = space_switch_exception, + [0x1d] = hfp_sqrt_exception, + [0x1e ... 0x37] = default_trap_handler, + [0x38] = do_dat_exception, + [0x39] = do_dat_exception, + [0x3a] = do_dat_exception, + [0x3b] = do_dat_exception, + [0x3c] = default_trap_handler, + [0x3d] = do_secure_storage_access, + [0x3e] = do_non_secure_storage_access, + [0x3f] = do_secure_storage_violation, + [0x40] = monitor_event_exception, + [0x41 ... 0x7f] = default_trap_handler, +}; + +#define COND_TRAP(x) asm( \ + ".weak " __stringify(x) "\n\t" \ + ".set " __stringify(x) "," \ + __stringify(default_trap_handler)) + +COND_TRAP(do_secure_storage_access); +COND_TRAP(do_non_secure_storage_access); +COND_TRAP(do_secure_storage_violation); |