linux_dsm_epyc7002/arch/microblaze/kernel/exceptions.c
Eric W. Biederman 3eb0f5193b signal: Ensure every siginfo we send has all bits initialized
Call clear_siginfo to ensure every stack allocated siginfo is properly
initialized before being passed to the signal sending functions.

Note: It is not safe to depend on C initializers to initialize struct
siginfo on the stack because C is allowed to skip holes when
initializing a structure.

The initialization of struct siginfo in tracehook_report_syscall_exit
was moved from the helper user_single_step_siginfo into
tracehook_report_syscall_exit itself, to make it clear that the local
variable siginfo gets fully initialized.

In a few cases the scope of struct siginfo has been reduced to make it
clear that siginfo siginfo is not used on other paths in the function
in which it is declared.

Instances of using memset to initialize siginfo have been replaced
with calls clear_siginfo for clarity.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:40:51 -05:00

157 lines
4.1 KiB
C

/*
* HW exception handling
*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008 PetaLogix
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
/*
* This file handles the architecture-dependent parts of hardware exceptions
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/kallsyms.h>
#include <asm/exceptions.h>
#include <asm/entry.h> /* For KM CPU var */
#include <linux/uaccess.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <asm/current.h>
#include <asm/cacheflush.h>
#define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
#define MICROBLAZE_IBUS_EXCEPTION 0x03
#define MICROBLAZE_DBUS_EXCEPTION 0x04
#define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05
#define MICROBLAZE_FPU_EXCEPTION 0x06
#define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
static DEFINE_SPINLOCK(die_lock);
void die(const char *str, struct pt_regs *fp, long err)
{
console_verbose();
spin_lock_irq(&die_lock);
pr_warn("Oops: %s, sig: %ld\n", str, err);
show_regs(fp);
spin_unlock_irq(&die_lock);
/* do_exit() should take care of panic'ing from an interrupt
* context so we don't handle it here
*/
do_exit(err);
}
/* for user application debugging */
asmlinkage void sw_exception(struct pt_regs *regs)
{
_exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
flush_dcache_range(regs->r16, regs->r16 + 0x4);
flush_icache_range(regs->r16, regs->r16 + 0x4);
}
void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
siginfo_t info;
if (kernel_mode(regs))
die("Exception in kernel mode", regs, signr);
clear_siginfo(&info);
info.si_signo = signr;
info.si_errno = 0;
info.si_code = code;
info.si_addr = (void __user *) addr;
force_sig_info(signr, &info, current);
}
asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
int fsr, int addr)
{
#ifdef CONFIG_MMU
addr = regs->pc;
#endif
#if 0
pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
type, user_mode(regs) ? "user" : "kernel", fsr,
(unsigned int) regs->pc, (unsigned int) regs->esr);
#endif
switch (type & 0x1F) {
case MICROBLAZE_ILL_OPCODE_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Illegal opcode exception in user mode\n");
_exception(SIGILL, regs, ILL_ILLOPC, addr);
return;
}
pr_warn("Illegal opcode exception in kernel mode.\n");
die("opcode exception", regs, SIGBUS);
break;
case MICROBLAZE_IBUS_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Instruction bus error exception in user mode\n");
_exception(SIGBUS, regs, BUS_ADRERR, addr);
return;
}
pr_warn("Instruction bus error exception in kernel mode.\n");
die("bus exception", regs, SIGBUS);
break;
case MICROBLAZE_DBUS_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Data bus error exception in user mode\n");
_exception(SIGBUS, regs, BUS_ADRERR, addr);
return;
}
pr_warn("Data bus error exception in kernel mode.\n");
die("bus exception", regs, SIGBUS);
break;
case MICROBLAZE_DIV_ZERO_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Divide by zero exception in user mode\n");
_exception(SIGFPE, regs, FPE_INTDIV, addr);
return;
}
pr_warn("Divide by zero exception in kernel mode.\n");
die("Divide by zero exception", regs, SIGBUS);
break;
case MICROBLAZE_FPU_EXCEPTION:
pr_debug("FPU exception\n");
/* IEEE FP exception */
/* I removed fsr variable and use code var for storing fsr */
if (fsr & FSR_IO)
fsr = FPE_FLTINV;
else if (fsr & FSR_OF)
fsr = FPE_FLTOVF;
else if (fsr & FSR_UF)
fsr = FPE_FLTUND;
else if (fsr & FSR_DZ)
fsr = FPE_FLTDIV;
else if (fsr & FSR_DO)
fsr = FPE_FLTRES;
_exception(SIGFPE, regs, fsr, addr);
break;
#ifdef CONFIG_MMU
case MICROBLAZE_PRIVILEGED_EXCEPTION:
pr_debug("Privileged exception\n");
_exception(SIGILL, regs, ILL_PRVOPC, addr);
break;
#endif
default:
/* FIXME what to do in unexpected exception */
pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",
type, (unsigned int) addr,
kernel_mode(regs) ? "kernel" : "user");
}
return;
}