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[MIPS] Fix handling of trap and breakpoint instructions

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With fixes and cleanups from Atsushi Nemoto (anemo@mba.ocn.ne.jp).

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle 2008-04-20 16:28:54 +01:00
parent cf85c10983
commit df2700519c
1 changed files with 41 additions and 56 deletions
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97
arch/mips/kernel/traps.c
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@ -675,10 +675,46 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
force_sig_info(SIGFPE, &info, current);
}
static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
const char *str)
{
siginfo_t info;
char b[40];
/*
* A short test says that IRIX 5.3 sends SIGTRAP for all trap
* insns, even for trap and break codes that indicate arithmetic
* failures. Weird ...
* But should we continue the brokenness??? --macro
*/
switch (code) {
case BRK_OVERFLOW:
case BRK_DIVZERO:
scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
die_if_kernel(b, regs);
if (code == BRK_DIVZERO)
info.si_code = FPE_INTDIV;
else
info.si_code = FPE_INTOVF;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_addr = (void __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
break;
case BRK_BUG:
die_if_kernel("Kernel bug detected", regs);
force_sig(SIGTRAP, current);
break;
default:
scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
die_if_kernel(b, regs);
force_sig(SIGTRAP, current);
}
}
asmlinkage void do_bp(struct pt_regs *regs)
{
unsigned int opcode, bcode;
siginfo_t info;
if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
goto out_sigsegv;
@ -690,35 +726,10 @@ asmlinkage void do_bp(struct pt_regs *regs)
* We handle both cases with a simple heuristics. --macro
*/
bcode = ((opcode >> 6) & ((1 << 20) - 1));
if (bcode < (1 << 10))
bcode <<= 10;
if (bcode >= (1 << 10))
bcode >>= 10;
/*
* (A short test says that IRIX 5.3 sends SIGTRAP for all break
* insns, even for break codes that indicate arithmetic failures.
* Weird ...)
* But should we continue the brokenness??? --macro
*/
switch (bcode) {
case BRK_OVERFLOW << 10:
case BRK_DIVZERO << 10:
die_if_kernel("Break instruction in kernel code", regs);
if (bcode == (BRK_DIVZERO << 10))
info.si_code = FPE_INTDIV;
else
info.si_code = FPE_INTOVF;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_addr = (void __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
break;
case BRK_BUG:
die("Kernel bug detected", regs);
break;
default:
die_if_kernel("Break instruction in kernel code", regs);
force_sig(SIGTRAP, current);
}
do_trap_or_bp(regs, bcode, "Break");
return;
out_sigsegv:
@ -728,7 +739,6 @@ out_sigsegv:
asmlinkage void do_tr(struct pt_regs *regs)
{
unsigned int opcode, tcode = 0;
siginfo_t info;
if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
goto out_sigsegv;
@ -737,32 +747,7 @@ asmlinkage void do_tr(struct pt_regs *regs)
if (!(opcode & OPCODE))
tcode = ((opcode >> 6) & ((1 << 10) - 1));
/*
* (A short test says that IRIX 5.3 sends SIGTRAP for all trap
* insns, even for trap codes that indicate arithmetic failures.
* Weird ...)
* But should we continue the brokenness??? --macro
*/
switch (tcode) {
case BRK_OVERFLOW:
case BRK_DIVZERO:
die_if_kernel("Trap instruction in kernel code", regs);
if (tcode == BRK_DIVZERO)
info.si_code = FPE_INTDIV;
else
info.si_code = FPE_INTOVF;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_addr = (void __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
break;
case BRK_BUG:
die("Kernel bug detected", regs);
break;
default:
die_if_kernel("Trap instruction in kernel code", regs);
force_sig(SIGTRAP, current);
}
do_trap_or_bp(regs, tcode, "Trap");
return;
out_sigsegv: