Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-02 00:51:44 +00:00
Code Issues Packages Projects Releases Wiki Activity
865e2acd3e
linux/arch/s390/kernel/traps.c
Linus Torvalds de927f6c0b s390 updates for 6.8 merge window 
- Add machine variable capacity information to /proc/sysinfo.
 
 - Limit the waste of page tables and always align vmalloc area size
   and base address on segment boundary.
 
 - Fix a memory leak when an attempt to register interruption sub class
   (ISC) for the adjunct-processor (AP) guest failed.
 
 - Reset response code AP_RESPONSE_INVALID_GISA to understandable
   by guest AP_RESPONSE_INVALID_ADDRESS in response to a failed
   interruption sub class (ISC) registration attempt.
 
 - Improve reaction to adjunct-processor (AP) AP_RESPONSE_OTHERWISE_CHANGED
   response code when enabling interrupts on behalf of a guest.
 
 - Fix incorrect sysfs 'status' attribute of adjunct-processor (AP) queue
   device bound to the vfio_ap device driver when the mediated device is
   attached to a guest, but the queue device is not passed through.
 
 - Rework struct ap_card to hold the whole adjunct-processor (AP) card
   hardware information. As result, all the ugly bit checks are replaced
   by simple evaluations of the required bit fields.
 
 - Improve handling of some weird scenarios between service element (SE)
   host and SE guest with adjunct-processor (AP) pass-through support.
 
 - Change local_ctl_set_bit() and local_ctl_clear_bit() so they return the
   previous value of the to be changed control register. This is useful if
   a bit is only changed temporarily and the previous content needs to be
   restored.
 
 - The kernel starts with machine checks disabled and is expected to enable
   it once trap_init() is called. However the implementation allows machine
   checks early. Consistently enable it in trap_init() only.
 
 - local_mcck_disable() and local_mcck_enable() assume that machine checks
   are always enabled. Instead implement and use local_mcck_save() and
   local_mcck_restore() to disable machine checks and restore the previous
   state.
 
 - Modification of floating point control (FPC) register of a traced
   process using ptrace interface may lead to corruption of the FPC
   register of the tracing process. Fix this.
 
 - kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control
   (FPC) register in vCPU, but may lead to corruption of the FPC register
   of the host process. Fix this.
 
 - Use READ_ONCE() to read a vCPU floating point register value from the
   memory mapped area. This avoids that, depending on code generation,
   a different value is tested for validity than the one that is used.
 
 - Get rid of test_fp_ctl(), since it is quite subtle to use it correctly.
   Instead copy a new floating point control register value into its save
   area and test the validity of the new value when loading it.
 
 - Remove superfluous save_fpu_regs() call.
 
 - Remove s390 support for ARCH_WANTS_DYNAMIC_TASK_STRUCT. All machines
   provide the vector facility since many years and the need to make the
   task structure size dependent on the vector facility does not exist.
 
 - Remove the "novx" kernel command line option, as the vector code runs
   without any problems since many years.
 
 - Add the vector facility to the z13 architecture level set (ALS).
   All hypervisors support the vector facility since many years.
   This allows compile time optimizations of the kernel.
 
 - Get rid of MACHINE_HAS_VX and replace it with cpu_has_vx(). As result,
   the compiled code will have less runtime checks and less code.
 
 - Convert pgste_get_lock() and pgste_set_unlock() ASM inlines to C.
 
 - Convert the struct subchannel spinlock from pointer to member.
 -----BEGIN PGP SIGNATURE-----
 
 iI0EABYIADUWIQQrtrZiYVkVzKQcYivNdxKlNrRb8AUCZZxnchccYWdvcmRlZXZA
 bGludXguaWJtLmNvbQAKCRDNdxKlNrRb8PyGAP9Z0Z1Pm3hPf24M4FgY5uuRqBHo
 VoiuohOZRGONwifnsgEAmN/3ba/7d/j0iMwpUdUFouiqtwTUihh15wYx1sH2IA8=
 =F6YD
 -----END PGP SIGNATURE-----

Merge tag 's390-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Alexander Gordeev:

 - Add machine variable capacity information to /proc/sysinfo.

 - Limit the waste of page tables and always align vmalloc area size and
   base address on segment boundary.

 - Fix a memory leak when an attempt to register interruption sub class
   (ISC) for the adjunct-processor (AP) guest failed.

 - Reset response code AP_RESPONSE_INVALID_GISA to understandable by
   guest AP_RESPONSE_INVALID_ADDRESS in response to a failed
   interruption sub class (ISC) registration attempt.

 - Improve reaction to adjunct-processor (AP)
   AP_RESPONSE_OTHERWISE_CHANGED response code when enabling interrupts
   on behalf of a guest.

 - Fix incorrect sysfs 'status' attribute of adjunct-processor (AP)
   queue device bound to the vfio_ap device driver when the mediated
   device is attached to a guest, but the queue device is not passed
   through.

 - Rework struct ap_card to hold the whole adjunct-processor (AP) card
   hardware information. As result, all the ugly bit checks are replaced
   by simple evaluations of the required bit fields.

 - Improve handling of some weird scenarios between service element (SE)
   host and SE guest with adjunct-processor (AP) pass-through support.

 - Change local_ctl_set_bit() and local_ctl_clear_bit() so they return
   the previous value of the to be changed control register. This is
   useful if a bit is only changed temporarily and the previous content
   needs to be restored.

 - The kernel starts with machine checks disabled and is expected to
   enable it once trap_init() is called. However the implementation
   allows machine checks early. Consistently enable it in trap_init()
   only.

 - local_mcck_disable() and local_mcck_enable() assume that machine
   checks are always enabled. Instead implement and use
   local_mcck_save() and local_mcck_restore() to disable machine checks
   and restore the previous state.

 - Modification of floating point control (FPC) register of a traced
   process using ptrace interface may lead to corruption of the FPC
   register of the tracing process. Fix this.

 - kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point
   control (FPC) register in vCPU, but may lead to corruption of the FPC
   register of the host process. Fix this.

 - Use READ_ONCE() to read a vCPU floating point register value from the
   memory mapped area. This avoids that, depending on code generation, a
   different value is tested for validity than the one that is used.

 - Get rid of test_fp_ctl(), since it is quite subtle to use it
   correctly. Instead copy a new floating point control register value
   into its save area and test the validity of the new value when
   loading it.

 - Remove superfluous save_fpu_regs() call.

 - Remove s390 support for ARCH_WANTS_DYNAMIC_TASK_STRUCT. All machines
   provide the vector facility since many years and the need to make the
   task structure size dependent on the vector facility does not exist.

 - Remove the "novx" kernel command line option, as the vector code runs
   without any problems since many years.

 - Add the vector facility to the z13 architecture level set (ALS). All
   hypervisors support the vector facility since many years. This allows
   compile time optimizations of the kernel.

 - Get rid of MACHINE_HAS_VX and replace it with cpu_has_vx(). As
   result, the compiled code will have less runtime checks and less
   code.

 - Convert pgste_get_lock() and pgste_set_unlock() ASM inlines to C.

 - Convert the struct subchannel spinlock from pointer to member.

* tag 's390-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (24 commits)
  Revert "s390: update defconfigs"
  s390/cio: make sch->lock spinlock pointer a member
  s390: update defconfigs
  s390/mm: convert pgste locking functions to C
  s390/fpu: get rid of MACHINE_HAS_VX
  s390/als: add vector facility to z13 architecture level set
  s390/fpu: remove "novx" option
  s390/fpu: remove ARCH_WANTS_DYNAMIC_TASK_STRUCT support
  KVM: s390: remove superfluous save_fpu_regs() call
  s390/fpu: get rid of test_fp_ctl()
  KVM: s390: use READ_ONCE() to read fpc register value
  KVM: s390: fix setting of fpc register
  s390/ptrace: handle setting of fpc register correctly
  s390/nmi: implement and use local_mcck_save() / local_mcck_restore()
  s390/nmi: consistently enable machine checks in trap_init()
  s390/ctlreg: return old register contents when changing bits
  s390/ap: handle outband SE bind state change
  s390/ap: store TAPQ hwinfo in struct ap_card
  s390/vfio-ap: fix sysfs status attribute for AP queue devices
  s390/vfio-ap: improve reaction to response code 07 from PQAP(AQIC) command
  ...
2024-01-10 18:18:20 -08:00

417 lines
11 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0
/*
* S390 version
* Copyright IBM Corp. 1999, 2000
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
*
* Derived from "arch/i386/kernel/traps.c"
* Copyright (C) 1991, 1992 Linus Torvalds
*/
/*
* '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>
#include <linux/sched/debug.h>
#include <linux/mm.h>
#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)
{
unsigned long address;
if (regs->int_code & 0x200)
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)
{
if (user_mode(regs)) {
force_sig_fault(si_signo, si_code, get_trap_ip(regs));
report_user_fault(regs, si_signo, 0);
} else {
if (!fixup_exception(regs))
die(regs, str);
}
}
static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
{
if (notify_die(DIE_TRAP, str, regs, 0,
regs->int_code, si_signo) == NOTIFY_STOP)
return;
do_report_trap(regs, si_signo, si_code, str);
}
NOKPROBE_SYMBOL(do_trap);
void do_per_trap(struct pt_regs *regs)
{
if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
return;
if (!current->ptrace)
return;
force_sig_fault(SIGTRAP, TRAP_HWBKPT,
(void __force __user *) current->thread.per_event.address);
}
NOKPROBE_SYMBOL(do_per_trap);
static void default_trap_handler(struct pt_regs *regs)
{
if (user_mode(regs)) {
report_user_fault(regs, SIGSEGV, 0);
force_exit_sig(SIGSEGV);
} else
die(regs, "Unknown program exception");
}
#define DO_ERROR_INFO(name, signr, sicode, str) \
static void name(struct pt_regs *regs) \
{ \
do_trap(regs, signr, sicode, str); \
}
DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
"addressing exception")
DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
"execute exception")
DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
"fixpoint divide exception")
DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
"fixpoint overflow exception")
DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
"HFP overflow exception")
DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
"HFP underflow exception")
DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
"HFP significance exception")
DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
"HFP divide exception")
DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
"HFP square root exception")
DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
"operand exception")
DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
"privileged operation")
DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
"special operation exception")
DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
"transaction constraint exception")
static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
{
int si_code = 0;
/* FPC[2] is Data Exception Code */
if ((fpc & 0x00000300) == 0) {
/* bits 6 and 7 of DXC are 0 iff IEEE exception */
if (fpc & 0x8000) /* invalid fp operation */
si_code = FPE_FLTINV;
else if (fpc & 0x4000) /* div by 0 */
si_code = FPE_FLTDIV;
else if (fpc & 0x2000) /* overflow */
si_code = FPE_FLTOVF;
else if (fpc & 0x1000) /* underflow */
si_code = FPE_FLTUND;
else if (fpc & 0x0800) /* inexact */
si_code = FPE_FLTRES;
}
do_trap(regs, SIGFPE, si_code, "floating point exception");
}
static void translation_specification_exception(struct pt_regs *regs)
{
/* May never happen. */
panic("Translation-Specification Exception");
}
static void illegal_op(struct pt_regs *regs)
{
__u8 opcode[6];
__u16 __user *location;
int is_uprobe_insn = 0;
int signal = 0;
location = get_trap_ip(regs);
if (user_mode(regs)) {
if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
return;
if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
if (current->ptrace)
force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
else
signal = SIGILL;
#ifdef CONFIG_UPROBES
} else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
is_uprobe_insn = 1;
#endif
} else
signal = SIGILL;
}
/*
* We got either an illegal op in kernel mode, or user space trapped
* on a uprobes illegal instruction. See if kprobes or uprobes picks
* it up. If not, SIGILL.
*/
if (is_uprobe_insn || !user_mode(regs)) {
if (notify_die(DIE_BPT, "bpt", regs, 0,
3, SIGTRAP) != NOTIFY_STOP)
signal = SIGILL;
}
if (signal)
do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
}
NOKPROBE_SYMBOL(illegal_op);
DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
"specification exception");
static void vector_exception(struct pt_regs *regs)
{
int si_code, vic;
if (!cpu_has_vx()) {
do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
return;
}
/* get vector interrupt code from fpc */
save_fpu_regs();
vic = (current->thread.fpu.fpc & 0xf00) >> 8;
switch (vic) {
case 1: /* invalid vector operation */
si_code = FPE_FLTINV;
break;
case 2: /* division by zero */
si_code = FPE_FLTDIV;
break;
case 3: /* overflow */
si_code = FPE_FLTOVF;
break;
case 4: /* underflow */
si_code = FPE_FLTUND;
break;
case 5: /* inexact */
si_code = FPE_FLTRES;
break;
default: /* unknown cause */
si_code = 0;
}
do_trap(regs, SIGFPE, si_code, "vector exception");
}
static void data_exception(struct pt_regs *regs)
{
save_fpu_regs();
if (current->thread.fpu.fpc & FPC_DXC_MASK)
do_fp_trap(regs, current->thread.fpu.fpc);
else
do_trap(regs, SIGILL, ILL_ILLOPN, "data exception");
}
static void space_switch_exception(struct pt_regs *regs)
{
/* Set user psw back to home space mode. */
if (user_mode(regs))
regs->psw.mask |= PSW_ASC_HOME;
/* Send SIGILL. */
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);
printk("Kernel stack overflow.\n");
show_regs(regs);
bust_spinlocks(0);
panic("Corrupt kernel stack, can't continue.");
}
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)
{
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);
Reference in New Issue View Git Blame Copy Permalink