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authorRalf Baechle <ralf@linux-mips.org>2008-04-20 16:28:54 +0100
committerRalf Baechle <ralf@linux-mips.org>2008-04-28 17:14:33 +0100
commitdf2700519c84ee8ee1e5ea165725c651f6d4d1a4 (patch)
tree51a7a8c8c7ee9dcd5a3b232afd14241ed46bad45 /arch
parentcf85c109831ce11ffa9befd4e970d6363e410a10 (diff)
[MIPS] Fix handling of trap and breakpoint instructions
With fixes and cleanups from Atsushi Nemoto (anemo@mba.ocn.ne.jp). Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kernel/traps.c89
1 files changed, 37 insertions, 52 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 88185cd40c3..cb8b0e2c795 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -675,35 +675,24 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
force_sig_info(SIGFPE, &info, current);
}
-asmlinkage void do_bp(struct pt_regs *regs)
+static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
+ const char *str)
{
- unsigned int opcode, bcode;
siginfo_t info;
-
- if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
- goto out_sigsegv;
-
- /*
- * There is the ancient bug in the MIPS assemblers that the break
- * code starts left to bit 16 instead to bit 6 in the opcode.
- * Gas is bug-compatible, but not always, grrr...
- * We handle both cases with a simple heuristics. --macro
- */
- bcode = ((opcode >> 6) & ((1 << 20) - 1));
- if (bcode < (1 << 10))
- bcode <<= 10;
+ char b[40];
/*
- * (A short test says that IRIX 5.3 sends SIGTRAP for all break
- * insns, even for break codes that indicate arithmetic failures.
- * Weird ...)
+ * 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 (bcode) {
- case BRK_OVERFLOW << 10:
- case BRK_DIVZERO << 10:
- die_if_kernel("Break instruction in kernel code", regs);
- if (bcode == (BRK_DIVZERO << 10))
+ 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;
@@ -713,12 +702,34 @@ asmlinkage void do_bp(struct pt_regs *regs)
force_sig_info(SIGFPE, &info, current);
break;
case BRK_BUG:
- die("Kernel bug detected", regs);
+ die_if_kernel("Kernel bug detected", regs);
+ force_sig(SIGTRAP, current);
break;
default:
- die_if_kernel("Break instruction in kernel code", regs);
+ 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;
+
+ if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
+ goto out_sigsegv;
+
+ /*
+ * There is the ancient bug in the MIPS assemblers that the break
+ * code starts left to bit 16 instead to bit 6 in the opcode.
+ * Gas is bug-compatible, but not always, grrr...
+ * We handle both cases with a simple heuristics. --macro
+ */
+ bcode = ((opcode >> 6) & ((1 << 20) - 1));
+ if (bcode >= (1 << 10))
+ bcode >>= 10;
+
+ 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: