From 5bc46ce26cfc42fa066b2206621587f9dea9a8a8 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Thu, 30 Jul 2020 11:09:51 +0000 Subject: csky: Optimize the trap processing flow - Seperate different trap functions - Add trap_no() - Remove panic code print - Redesign die_if_kerenl to die with riscv's - Print exact trap info for app segment fault [ 17.389321] gzip[126]: unhandled signal 11 code 0x3 at 0x0007835a in busybox[8000+d4000] [ 17.393882] [ 17.393882] CURRENT PROCESS: [ 17.393882] [ 17.394309] COMM=gzip PID=126 [ 17.394513] TEXT=00008000-000db2e4 DATA=000dcf14-000dd1ad BSS=000dd1ad-000ff000 [ 17.395499] USER-STACK=7f888e50 KERNEL-STACK=bf130300 [ 17.395499] [ 17.396801] PC: 0x0007835a (0x7835a) [ 17.397048] LR: 0x000058b4 (0x58b4) [ 17.397285] SP: 0xbe519f68 [ 17.397555] orig_a0: 0x00002852 [ 17.397886] PSR: 0x00020341 [ 17.398356] a0: 0x00002852 a1: 0x000f2f5a a2: 0x0000d7ae a3: 0x0000005d [ 17.399289] r4: 0x000de150 r5: 0x00000002 r6: 0x00000102 r7: 0x00007efa [ 17.399800] r8: 0x7f888bc4 r9: 0x00000001 r10: 0x000002eb r11: 0x0000aac1 [ 17.400166] r12: 0x00002ef2 r13: 0x00000007 r15: 0x000058b4 [ 17.400531] r16: 0x0000004c r17: 0x00000031 r18: 0x000f5816 r19: 0x000e8068 [ 17.401006] r20: 0x000f5818 r21: 0x000e8068 r22: 0x000f5918 r23: 0x90000000 [ 17.401721] r24: 0x00000031 r25: 0x000000c8 r26: 0x00000000 r27: 0x00000000 [ 17.402199] r28: 0x2ac2a000 r29: 0x00000000 r30: 0x00000000 tls: 0x2aadbaa8 [ 17.402686] hi: 0x00120340 lo: 0x7f888bec /etc/init.ci/ntfs3g_run: line 61: 126 Segmentation fault gzip -c -9 /mnt/test.bin > /mnt/test_bin.gz Signed-off-by: Guo Ren Cc: Arnd Bergmann --- arch/csky/kernel/traps.c | 223 +++++++++++++++++++++++++++++++---------------- 1 file changed, 147 insertions(+), 76 deletions(-) (limited to 'arch/csky/kernel/traps.c') diff --git a/arch/csky/kernel/traps.c b/arch/csky/kernel/traps.c index fcc3a69831ad..959a917c989d 100644 --- a/arch/csky/kernel/traps.c +++ b/arch/csky/kernel/traps.c @@ -15,6 +15,8 @@ #include #include #include +#include +#include #include #include @@ -27,6 +29,8 @@ #include #endif +int show_unhandled_signals = 1; + /* Defined in entry.S */ asmlinkage void csky_trap(void); @@ -77,117 +81,184 @@ void __init trap_init(void) #endif } -void die_if_kernel(char *str, struct pt_regs *regs, int nr) +static DEFINE_SPINLOCK(die_lock); + +void die(struct pt_regs *regs, const char *str) { - if (user_mode(regs)) - return; + static int die_counter; + int ret; + oops_enter(); + + spin_lock_irq(&die_lock); console_verbose(); - pr_err("%s: %08x\n", str, nr); + bust_spinlocks(1); + + pr_emerg("%s [#%d]\n", str, ++die_counter); + print_modules(); show_regs(regs); + show_stack(current, (unsigned long *)regs->regs[4], KERN_INFO); + + ret = notify_die(DIE_OOPS, str, regs, 0, trap_no(regs), SIGSEGV); + + bust_spinlocks(0); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); - do_exit(SIGSEGV); + spin_unlock_irq(&die_lock); + oops_exit(); + + if (in_interrupt()) + panic("Fatal exception in interrupt"); + if (panic_on_oops) + panic("Fatal exception"); + if (ret != NOTIFY_STOP) + do_exit(SIGSEGV); } -void buserr(struct pt_regs *regs) +void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr) { -#ifdef CONFIG_CPU_CK810 - static unsigned long prev_pc; + struct task_struct *tsk = current; - if ((regs->pc == prev_pc) && prev_pc != 0) { - prev_pc = 0; - } else { - prev_pc = regs->pc; - return; + if (show_unhandled_signals && unhandled_signal(tsk, signo) + && printk_ratelimit()) { + pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x%08lx", + tsk->comm, task_pid_nr(tsk), signo, code, addr); + print_vma_addr(KERN_CONT " in ", instruction_pointer(regs)); + pr_cont("\n"); + show_regs(regs); } -#endif - die_if_kernel("Kernel mode BUS error", regs, 0); + force_sig_fault(signo, code, (void __user *)addr); +} - pr_err("User mode Bus Error\n"); - show_regs(regs); +static void do_trap_error(struct pt_regs *regs, int signo, int code, + unsigned long addr, const char *str) +{ + current->thread.trap_no = trap_no(regs); - force_sig_fault(SIGSEGV, 0, (void __user *)regs->pc); + if (user_mode(regs)) { + do_trap(regs, signo, code, addr); + } else { + if (!fixup_exception(regs)) + die(regs, str); + } } -asmlinkage void trap_c(struct pt_regs *regs) -{ - int sig; - unsigned long vector; - siginfo_t info; - struct task_struct *tsk = current; +#define DO_ERROR_INFO(name, signo, code, str) \ +asmlinkage __visible void name(struct pt_regs *regs) \ +{ \ + do_trap_error(regs, signo, code, regs->pc, "Oops - " str); \ +} - vector = (regs->sr >> 16) & 0xff; +DO_ERROR_INFO(do_trap_unknown, + SIGILL, ILL_ILLTRP, "unknown exception"); +DO_ERROR_INFO(do_trap_zdiv, + SIGFPE, FPE_INTDIV, "error zero div exception"); +DO_ERROR_INFO(do_trap_buserr, + SIGSEGV, ILL_ILLADR, "error bus error exception"); - switch (vector) { - case VEC_ZERODIV: - die_if_kernel("Kernel mode ZERO DIV", regs, vector); - sig = SIGFPE; - break; - /* ptrace */ - case VEC_TRACE: +asmlinkage void do_trap_misaligned(struct pt_regs *regs) +{ +#ifdef CONFIG_CPU_NEED_SOFTALIGN + csky_alignment(regs); +#else + current->thread.trap_no = trap_no(regs); + do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->pc, + "Oops - load/store address misaligned"); +#endif +} + +asmlinkage void do_trap_bkpt(struct pt_regs *regs) +{ #ifdef CONFIG_KPROBES - if (kprobe_single_step_handler(regs)) - return; + if (kprobe_single_step_handler(regs)) + return; #endif #ifdef CONFIG_UPROBES - if (uprobe_single_step_handler(regs)) - return; + if (uprobe_single_step_handler(regs)) + return; #endif - info.si_code = TRAP_TRACE; - sig = SIGTRAP; - break; - case VEC_ILLEGAL: - tsk->thread.trap_no = vector; + if (user_mode(regs)) { + send_sig(SIGTRAP, current, 0); + return; + } + + do_trap_error(regs, SIGILL, ILL_ILLTRP, regs->pc, + "Oops - illegal trap exception"); +} + +asmlinkage void do_trap_illinsn(struct pt_regs *regs) +{ + current->thread.trap_no = trap_no(regs); + #ifdef CONFIG_KPROBES - if (kprobe_breakpoint_handler(regs)) - return; + if (kprobe_breakpoint_handler(regs)) + return; #endif #ifdef CONFIG_UPROBES - if (uprobe_breakpoint_handler(regs)) - return; + if (uprobe_breakpoint_handler(regs)) + return; #endif - die_if_kernel("Kernel mode ILLEGAL", regs, vector); #ifndef CONFIG_CPU_NO_USER_BKPT - if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT) + if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT) { + send_sig(SIGTRAP, current, 0); + return; + } #endif - { - sig = SIGILL; - break; - } - /* gdbserver breakpoint */ + + do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc, + "Oops - illegal instruction exception"); +} + +asmlinkage void do_trap_fpe(struct pt_regs *regs) +{ +#ifdef CONFIG_CPU_HAS_FP + return fpu_fpe(regs); +#else + do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc, + "Oops - fpu instruction exception"); +#endif +} + +asmlinkage void do_trap_priv(struct pt_regs *regs) +{ +#ifdef CONFIG_CPU_HAS_FP + if (user_mode(regs) && fpu_libc_helper(regs)) + return; +#endif + do_trap_error(regs, SIGILL, ILL_PRVOPC, regs->pc, + "Oops - illegal privileged exception"); +} + +asmlinkage void trap_c(struct pt_regs *regs) +{ + switch (trap_no(regs)) { + case VEC_ZERODIV: + do_trap_zdiv(regs); + break; + case VEC_TRACE: + do_trap_bkpt(regs); + break; + case VEC_ILLEGAL: + do_trap_illinsn(regs); + break; case VEC_TRAP1: - /* jtagserver breakpoint */ case VEC_BREAKPOINT: - die_if_kernel("Kernel mode BKPT", regs, vector); - info.si_code = TRAP_BRKPT; - sig = SIGTRAP; + do_trap_bkpt(regs); break; case VEC_ACCESS: - tsk->thread.trap_no = vector; - return buserr(regs); -#ifdef CONFIG_CPU_NEED_SOFTALIGN + do_trap_buserr(regs); + break; case VEC_ALIGN: - tsk->thread.trap_no = vector; - return csky_alignment(regs); -#endif -#ifdef CONFIG_CPU_HAS_FPU + do_trap_misaligned(regs); + break; case VEC_FPE: - tsk->thread.trap_no = vector; - die_if_kernel("Kernel mode FPE", regs, vector); - return fpu_fpe(regs); + do_trap_fpe(regs); + break; case VEC_PRIV: - tsk->thread.trap_no = vector; - die_if_kernel("Kernel mode PRIV", regs, vector); - if (fpu_libc_helper(regs)) - return; -#endif + do_trap_priv(regs); + break; default: - sig = SIGSEGV; + do_trap_unknown(regs); break; } - - tsk->thread.trap_no = vector; - - send_sig(sig, current, 0); } -- cgit