summaryrefslogtreecommitdiff
path: root/arch/s390/kernel/traps.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/kernel/traps.c')
-rw-r--r--arch/s390/kernel/traps.c200
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 = &current->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);