From 0375a73c6f1be69d5a9b439a7e95b92e54b3c09b Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Thu, 14 Jun 2012 14:46:36 +0900 Subject: sh64: Attempt to make reserved insn trap handler resemble C. This has been long overdue. No functional changes. Signed-off-by: Paul Mundt --- arch/sh/kernel/traps_64.c | 386 +++++++++++++++++++++++----------------------- 1 file changed, 195 insertions(+), 191 deletions(-) (limited to 'arch/sh/kernel') diff --git a/arch/sh/kernel/traps_64.c b/arch/sh/kernel/traps_64.c index 75bef61892d2..f87d20da1791 100644 --- a/arch/sh/kernel/traps_64.c +++ b/arch/sh/kernel/traps_64.c @@ -32,195 +32,6 @@ #include #include -static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name, - unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk); - -#define DO_ERROR(trapnr, signr, str, name, tsk) \ -asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \ -{ \ - do_unhandled_exception(trapnr, signr, str, __stringify(name), error_code, regs, current); \ -} - -DO_ERROR(13, SIGILL, "illegal slot instruction", illegal_slot_inst, current) -DO_ERROR(87, SIGSEGV, "address error (exec)", address_error_exec, current) - - -/* Implement misaligned load/store handling for kernel (and optionally for user - mode too). Limitation : only SHmedia mode code is handled - there is no - handling at all for misaligned accesses occurring in SHcompact code yet. */ - -static int misaligned_fixup(struct pt_regs *regs); - -asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs) -{ - if (misaligned_fixup(regs) < 0) { - do_unhandled_exception(7, SIGSEGV, "address error(load)", - "do_address_error_load", - error_code, regs, current); - } - return; -} - -asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs) -{ - if (misaligned_fixup(regs) < 0) { - do_unhandled_exception(8, SIGSEGV, "address error(store)", - "do_address_error_store", - error_code, regs, current); - } - return; -} - -#if defined(CONFIG_SH64_ID2815_WORKAROUND) - -#define OPCODE_INVALID 0 -#define OPCODE_USER_VALID 1 -#define OPCODE_PRIV_VALID 2 - -/* getcon/putcon - requires checking which control register is referenced. */ -#define OPCODE_CTRL_REG 3 - -/* Table of valid opcodes for SHmedia mode. - Form a 10-bit value by concatenating the major/minor opcodes i.e. - opcode[31:26,20:16]. The 6 MSBs of this value index into the following - array. The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to - LSBs==4'b0000 etc). */ -static unsigned long shmedia_opcode_table[64] = { - 0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015, - 0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000, - 0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000, - 0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000, - 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555, - 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555, - 0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555, - 0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000 -}; - -void do_reserved_inst(unsigned long error_code, struct pt_regs *regs) -{ - /* Workaround SH5-101 cut2 silicon defect #2815 : - in some situations, inter-mode branches from SHcompact -> SHmedia - which should take ITLBMISS or EXECPROT exceptions at the target - falsely take RESINST at the target instead. */ - - unsigned long opcode = 0x6ff4fff0; /* guaranteed reserved opcode */ - unsigned long pc, aligned_pc; - int get_user_error; - int trapnr = 12; - int signr = SIGILL; - char *exception_name = "reserved_instruction"; - - pc = regs->pc; - if ((pc & 3) == 1) { - /* SHmedia : check for defect. This requires executable vmas - to be readable too. */ - aligned_pc = pc & ~3; - if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) { - get_user_error = -EFAULT; - } else { - get_user_error = __get_user(opcode, (unsigned long *)aligned_pc); - } - if (get_user_error >= 0) { - unsigned long index, shift; - unsigned long major, minor, combined; - unsigned long reserved_field; - reserved_field = opcode & 0xf; /* These bits are currently reserved as zero in all valid opcodes */ - major = (opcode >> 26) & 0x3f; - minor = (opcode >> 16) & 0xf; - combined = (major << 4) | minor; - index = major; - shift = minor << 1; - if (reserved_field == 0) { - int opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3; - switch (opcode_state) { - case OPCODE_INVALID: - /* Trap. */ - break; - case OPCODE_USER_VALID: - /* Restart the instruction : the branch to the instruction will now be from an RTE - not from SHcompact so the silicon defect won't be triggered. */ - return; - case OPCODE_PRIV_VALID: - if (!user_mode(regs)) { - /* Should only ever get here if a module has - SHcompact code inside it. If so, the same fix up is needed. */ - return; /* same reason */ - } - /* Otherwise, user mode trying to execute a privileged instruction - - fall through to trap. */ - break; - case OPCODE_CTRL_REG: - /* If in privileged mode, return as above. */ - if (!user_mode(regs)) return; - /* In user mode ... */ - if (combined == 0x9f) { /* GETCON */ - unsigned long regno = (opcode >> 20) & 0x3f; - if (regno >= 62) { - return; - } - /* Otherwise, reserved or privileged control register, => trap */ - } else if (combined == 0x1bf) { /* PUTCON */ - unsigned long regno = (opcode >> 4) & 0x3f; - if (regno >= 62) { - return; - } - /* Otherwise, reserved or privileged control register, => trap */ - } else { - /* Trap */ - } - break; - default: - /* Fall through to trap. */ - break; - } - } - /* fall through to normal resinst processing */ - } else { - /* Error trying to read opcode. This typically means a - real fault, not a RESINST any more. So change the - codes. */ - trapnr = 87; - exception_name = "address error (exec)"; - signr = SIGSEGV; - } - } - - do_unhandled_exception(trapnr, signr, exception_name, "do_reserved_inst", error_code, regs, current); -} - -#else /* CONFIG_SH64_ID2815_WORKAROUND */ - -/* If the workaround isn't needed, this is just a straightforward reserved - instruction */ -DO_ERROR(12, SIGILL, "reserved instruction", reserved_inst, current) - -#endif /* CONFIG_SH64_ID2815_WORKAROUND */ - -/* Called with interrupts disabled */ -asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs) -{ - die_if_kernel("exception", regs, ex); -} - -int do_unknown_trapa(unsigned long scId, struct pt_regs *regs) -{ - /* Syscall debug */ - printk("System call ID error: [0x1#args:8 #syscall:16 0x%lx]\n", scId); - - die_if_kernel("unknown trapa", regs, scId); - - return -ENOSYS; -} - -static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name, - unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk) -{ - if (user_mode(regs)) - force_sig(signr, tsk); - - die_if_no_fixup(str, regs, error_code); -} - static int read_opcode(reg_size_t pc, insn_size_t *result_opcode, int from_user_mode) { int get_user_error; @@ -784,7 +595,201 @@ static int misaligned_fixup(struct pt_regs *regs) regs->pc += 4; /* Skip the instruction that's just been emulated */ return 0; } +} + +static void do_unhandled_exception(int signr, char *str, unsigned long error, + struct pt_regs *regs) +{ + if (user_mode(regs)) + force_sig(signr, current); + + die_if_no_fixup(str, regs, error); +} + +#define DO_ERROR(signr, str, name) \ +asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \ +{ \ + do_unhandled_exception(signr, str, error_code, regs); \ +} + +DO_ERROR(SIGILL, "illegal slot instruction", illegal_slot_inst) +DO_ERROR(SIGSEGV, "address error (exec)", address_error_exec) + +#if defined(CONFIG_SH64_ID2815_WORKAROUND) + +#define OPCODE_INVALID 0 +#define OPCODE_USER_VALID 1 +#define OPCODE_PRIV_VALID 2 + +/* getcon/putcon - requires checking which control register is referenced. */ +#define OPCODE_CTRL_REG 3 + +/* Table of valid opcodes for SHmedia mode. + Form a 10-bit value by concatenating the major/minor opcodes i.e. + opcode[31:26,20:16]. The 6 MSBs of this value index into the following + array. The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to + LSBs==4'b0000 etc). */ +static unsigned long shmedia_opcode_table[64] = { + 0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015, + 0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000, + 0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000, + 0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000, + 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555, + 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555, + 0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555, + 0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000 +}; + +/* Workaround SH5-101 cut2 silicon defect #2815 : + in some situations, inter-mode branches from SHcompact -> SHmedia + which should take ITLBMISS or EXECPROT exceptions at the target + falsely take RESINST at the target instead. */ +void do_reserved_inst(unsigned long error_code, struct pt_regs *regs) +{ + insn_size_t opcode = 0x6ff4fff0; /* guaranteed reserved opcode */ + unsigned long pc, aligned_pc; + unsigned long index, shift; + unsigned long major, minor, combined; + unsigned long reserved_field; + int opcode_state; + int get_user_error; + int signr = SIGILL; + char *exception_name = "reserved_instruction"; + + pc = regs->pc; + + /* SHcompact is not handled */ + if (unlikely((pc & 3) == 0)) + goto out; + + /* SHmedia : check for defect. This requires executable vmas + to be readable too. */ + aligned_pc = pc & ~3; + if (!access_ok(VERIFY_READ, aligned_pc, sizeof(insn_size_t))) + get_user_error = -EFAULT; + else + get_user_error = __get_user(opcode, (insn_size_t *)aligned_pc); + + if (get_user_error < 0) { + /* + * Error trying to read opcode. This typically means a + * real fault, not a RESINST any more. So change the + * codes. + */ + exception_name = "address error (exec)"; + signr = SIGSEGV; + goto out; + } + + /* These bits are currently reserved as zero in all valid opcodes */ + reserved_field = opcode & 0xf; + if (unlikely(reserved_field)) + goto out; /* invalid opcode */ + + major = (opcode >> 26) & 0x3f; + minor = (opcode >> 16) & 0xf; + combined = (major << 4) | minor; + index = major; + shift = minor << 1; + opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3; + switch (opcode_state) { + case OPCODE_INVALID: + /* Trap. */ + break; + case OPCODE_USER_VALID: + /* + * Restart the instruction: the branch to the instruction + * will now be from an RTE not from SHcompact so the + * silicon defect won't be triggered. + */ + return; + case OPCODE_PRIV_VALID: + if (!user_mode(regs)) { + /* + * Should only ever get here if a module has + * SHcompact code inside it. If so, the same fix + * up is needed. + */ + return; /* same reason */ + } + + /* + * Otherwise, user mode trying to execute a privileged + * instruction - fall through to trap. + */ + break; + case OPCODE_CTRL_REG: + /* If in privileged mode, return as above. */ + if (!user_mode(regs)) + return; + + /* In user mode ... */ + if (combined == 0x9f) { /* GETCON */ + unsigned long regno = (opcode >> 20) & 0x3f; + + if (regno >= 62) + return; + + /* reserved/privileged control register => trap */ + } else if (combined == 0x1bf) { /* PUTCON */ + unsigned long regno = (opcode >> 4) & 0x3f; + + if (regno >= 62) + return; + + /* reserved/privileged control register => trap */ + } + + break; + default: + /* Fall through to trap. */ + break; + } +out: + do_unhandled_exception(signr, exception_name, error_code, regs); +} + +#else /* CONFIG_SH64_ID2815_WORKAROUND */ + +/* If the workaround isn't needed, this is just a straightforward reserved + instruction */ +DO_ERROR(SIGILL, "reserved instruction", reserved_inst) + +#endif /* CONFIG_SH64_ID2815_WORKAROUND */ + +/* Called with interrupts disabled */ +asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs) +{ + die_if_kernel("exception", regs, ex); +} + +asmlinkage int do_unknown_trapa(unsigned long scId, struct pt_regs *regs) +{ + /* Syscall debug */ + printk("System call ID error: [0x1#args:8 #syscall:16 0x%lx]\n", scId); + + die_if_kernel("unknown trapa", regs, scId); + + return -ENOSYS; +} + +/* Implement misaligned load/store handling for kernel (and optionally for user + mode too). Limitation : only SHmedia mode code is handled - there is no + handling at all for misaligned accesses occurring in SHcompact code yet. */ + +asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs) +{ + if (misaligned_fixup(regs) < 0) + do_unhandled_exception(SIGSEGV, "address error(load)", + error_code, regs); +} + +asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs) +{ + if (misaligned_fixup(regs) < 0) + do_unhandled_exception(SIGSEGV, "address error(store)", + error_code, regs); } asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs) @@ -797,10 +802,9 @@ asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs) of access we make to them - just go direct to their physical addresses. */ exp_cause = peek_real_address_q(DM_EXP_CAUSE_PHY); - if (exp_cause & ~4) { + if (exp_cause & ~4) printk("DM.EXP_CAUSE had unexpected bits set (=%08lx)\n", (unsigned long)(exp_cause & 0xffffffff)); - } show_state(); /* Clear all DEBUGINT causes */ poke_real_address_q(DM_EXP_CAUSE_PHY, 0x0); -- cgit v1.2.3-55-g7522