2a0b24f56c2492b932f1aed617ae80fb23500d21 broke Trap exception handling in
the standard MIPS mode. Additionally the microMIPS-mode trap code mask is
wrong, as it's a 4-bit field. Here's a fix.
Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxxxxxxx>
---
Ralf, please apply. Also the mention of: "A few NOP instructions are used
to maintain the correct alignment[...]" in the commit referred makes me
feel scared -- there is that .align pseudo-op, you know... Maciej
linux-mips-do-tr.diff
arch/mips/kernel/traps.c | 28 +++++++++++++++-------------
1 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index e3be670..a75ae40 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -897,22 +897,24 @@ out_sigsegv:
asmlinkage void do_tr(struct pt_regs *regs)
{
- unsigned int opcode, tcode = 0;
+ u32 opcode, tcode = 0;
u16 instr[2];
- unsigned long epc = exception_epc(regs);
+ unsigned long epc = msk_isa16_mode(exception_epc(regs));
- if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc))) ||
- (__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2))))
+ if (get_isa16_mode(regs->cp0_epc)) {
+ if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
+ __get_user(instr[1], (u16 __user *)(epc + 2)))
goto out_sigsegv;
- opcode = (instr[0] << 16) | instr[1];
-
- /* Immediate versions don't provide a code. */
- if (!(opcode & OPCODE)) {
- if (get_isa16_mode(regs->cp0_epc))
- /* microMIPS */
- tcode = (opcode >> 12) & 0x1f;
- else
- tcode = ((opcode >> 6) & ((1 << 10) - 1));
+ opcode = (instr[0] << 16) | instr[1];
+ /* Immediate versions don't provide a code. */
+ if (!(opcode & OPCODE))
+ tcode = (opcode >> 12) & ((1 << 4) - 1);
+ } else {
+ if (__get_user(opcode, (u32 __user *)epc))
+ goto out_sigsegv;
+ /* Immediate versions don't provide a code. */
+ if (!(opcode & OPCODE))
+ tcode = (opcode >> 6) & ((1 << 10) - 1);
}
do_trap_or_bp(regs, tcode, "Trap");
