diff options
Diffstat (limited to 'arch/xtensa/kernel')
-rw-r--r-- | arch/xtensa/kernel/entry.S | 34 | ||||
-rw-r--r-- | arch/xtensa/kernel/signal.c | 26 | ||||
-rw-r--r-- | arch/xtensa/kernel/stacktrace.c | 5 | ||||
-rw-r--r-- | arch/xtensa/kernel/traps.c | 4 |
4 files changed, 61 insertions, 8 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 9afe8f612f23..9e3676879168 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1003,7 +1003,41 @@ ENTRY(fast_alloca) 4: j _WindowUnderflow4 ENDPROC(fast_alloca) +#ifdef CONFIG_USER_ABI_CALL0_PROBE /* + * fast illegal instruction handler. + * + * This is used to fix up user PS.WOE on the exception caused + * by the first opcode related to register window. If PS.WOE is + * already set it goes directly to the common user exception handler. + * + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + */ + +ENTRY(fast_illegal_instruction_user) + + rsr a0, ps + bbsi.l a0, PS_WOE_BIT, user_exception + s32i a3, a2, PT_AREG3 + movi a3, PS_WOE_MASK + or a0, a0, a3 + wsr a0, ps + l32i a3, a2, PT_AREG3 + l32i a0, a2, PT_AREG0 + rsr a2, depc + rfe + +ENDPROC(fast_illegal_instruction_user) +#endif + + /* * fast system calls. * * WARNING: The kernel doesn't save the entire user context before diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index fbedf2aba09d..dae83cddd6ca 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -335,7 +335,8 @@ static int setup_frame(struct ksignal *ksig, sigset_t *set, { struct rt_sigframe *frame; int err = 0, sig = ksig->sig; - unsigned long sp, ra, tp; + unsigned long sp, ra, tp, ps; + unsigned int base; sp = regs->areg[1]; @@ -385,17 +386,26 @@ static int setup_frame(struct ksignal *ksig, sigset_t *set, /* Set up registers for signal handler; preserve the threadptr */ tp = regs->threadptr; + ps = regs->ps; start_thread(regs, (unsigned long) ksig->ka.sa.sa_handler, (unsigned long) frame); - /* Set up a stack frame for a call4 - * Note: PS.CALLINC is set to one by start_thread - */ - regs->areg[4] = (((unsigned long) ra) & 0x3fffffff) | 0x40000000; - regs->areg[6] = (unsigned long) sig; - regs->areg[7] = (unsigned long) &frame->info; - regs->areg[8] = (unsigned long) &frame->uc; + /* Set up a stack frame for a call4 if userspace uses windowed ABI */ + if (ps & PS_WOE_MASK) { + base = 4; + regs->areg[base] = + (((unsigned long) ra) & 0x3fffffff) | 0x40000000; + ps = (ps & ~(PS_CALLINC_MASK | PS_OWB_MASK)) | + (1 << PS_CALLINC_SHIFT); + } else { + base = 0; + regs->areg[base] = (unsigned long) ra; + } + regs->areg[base + 2] = (unsigned long) sig; + regs->areg[base + 3] = (unsigned long) &frame->info; + regs->areg[base + 4] = (unsigned long) &frame->uc; regs->threadptr = tp; + regs->ps = ps; pr_debug("SIG rt deliver (%s:%d): signal=%d sp=%p pc=%08lx\n", current->comm, current->pid, sig, frame, regs->pc); diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c index b9f82510c650..c822abb93d20 100644 --- a/arch/xtensa/kernel/stacktrace.c +++ b/arch/xtensa/kernel/stacktrace.c @@ -44,6 +44,11 @@ void xtensa_backtrace_user(struct pt_regs *regs, unsigned int depth, if (pc == 0 || pc >= TASK_SIZE || ufn(&frame, data)) return; + if (IS_ENABLED(CONFIG_USER_ABI_CALL0_ONLY) || + (IS_ENABLED(CONFIG_USER_ABI_CALL0_PROBE) && + !(regs->ps & PS_WOE_MASK))) + return; + /* Two steps: * * 1. Look through the register window for the diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index f060348c1b23..4a6c495ce9b6 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -51,6 +51,7 @@ extern void kernel_exception(void); extern void user_exception(void); +extern void fast_illegal_instruction_user(void); extern void fast_syscall_user(void); extern void fast_alloca(void); extern void fast_unaligned(void); @@ -87,6 +88,9 @@ typedef struct { static dispatch_init_table_t __initdata dispatch_init_table[] = { +#ifdef CONFIG_USER_ABI_CALL0_PROBE +{ EXCCAUSE_ILLEGAL_INSTRUCTION, USER, fast_illegal_instruction_user }, +#endif { EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction}, { EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user }, { EXCCAUSE_SYSTEM_CALL, 0, system_call }, |