From 5bc46ce26cfc42fa066b2206621587f9dea9a8a8 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Thu, 30 Jul 2020 11:09:51 +0000 Subject: [PATCH] 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/include/asm/bug.h | 3 +- arch/csky/include/asm/ptrace.h | 1 + arch/csky/kernel/ptrace.c | 29 +---- arch/csky/kernel/traps.c | 223 ++++++++++++++++++++++----------- arch/csky/mm/fault.c | 10 +- 5 files changed, 157 insertions(+), 109 deletions(-) diff --git a/arch/csky/include/asm/bug.h b/arch/csky/include/asm/bug.h index bd7b3235bb84f5..33ebd16b9c7874 100644 --- a/arch/csky/include/asm/bug.h +++ b/arch/csky/include/asm/bug.h @@ -20,7 +20,8 @@ do { \ struct pt_regs; -void die_if_kernel(char *str, struct pt_regs *regs, int nr); +void die(struct pt_regs *regs, const char *str); void show_regs(struct pt_regs *regs); +void show_code(struct pt_regs *regs); #endif /* __ASM_CSKY_BUG_H */ diff --git a/arch/csky/include/asm/ptrace.h b/arch/csky/include/asm/ptrace.h index 82da5e08558d90..91ceb1b454c99d 100644 --- a/arch/csky/include/asm/ptrace.h +++ b/arch/csky/include/asm/ptrace.h @@ -24,6 +24,7 @@ #define user_mode(regs) (!((regs)->sr & PS_S)) #define instruction_pointer(regs) ((regs)->pc) #define profile_pc(regs) instruction_pointer(regs) +#define trap_no(regs) ((regs->sr >> 16) & 0xff) static inline void instruction_pointer_set(struct pt_regs *regs, unsigned long val) diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c index 0de10f7beae674..b06612c408c4e9 100644 --- a/arch/csky/kernel/ptrace.c +++ b/arch/csky/kernel/ptrace.c @@ -347,13 +347,8 @@ asmlinkage void syscall_trace_exit(struct pt_regs *regs) trace_sys_exit(regs, syscall_get_return_value(current, regs)); } -extern void show_stack(struct task_struct *task, unsigned long *stack, const char *loglvl); void show_regs(struct pt_regs *fp) { - unsigned long *sp; - unsigned char *tp; - int i; - pr_info("\nCURRENT PROCESS:\n\n"); pr_info("COMM=%s PID=%d\n", current->comm, current->pid); @@ -400,29 +395,9 @@ void show_regs(struct pt_regs *fp) fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]); pr_info("r10: 0x%08lx r11: 0x%08lx r12: 0x%08lx r13: 0x%08lx\n", fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]); - pr_info("r14: 0x%08lx r1: 0x%08lx r15: 0x%08lx\n", - fp->regs[8], fp->regs[9], fp->lr); + pr_info("r14: 0x%08lx r1: 0x%08lx\n", + fp->regs[8], fp->regs[9]); #endif - pr_info("\nCODE:"); - tp = ((unsigned char *) fp->pc) - 0x20; - tp += ((int)tp % 4) ? 2 : 0; - for (sp = (unsigned long *) tp, i = 0; (i < 0x40); i += 4) { - if ((i % 0x10) == 0) - pr_cont("\n%08x: ", (int) (tp + i)); - pr_cont("%08x ", (int) *sp++); - } - pr_cont("\n"); - - pr_info("\nKERNEL STACK:"); - tp = ((unsigned char *) fp) - 0x40; - for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) { - if ((i % 0x10) == 0) - pr_cont("\n%08x: ", (int) (tp + i)); - pr_cont("%08x ", (int) *sp++); - } - pr_cont("\n"); - - show_stack(NULL, (unsigned long *)fp->regs[4], KERN_INFO); return; } diff --git a/arch/csky/kernel/traps.c b/arch/csky/kernel/traps.c index fcc3a69831adf1..959a917c989d85 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); } diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c index 0b9cbf2cf6a975..b1dce9f2f04dd8 100644 --- a/arch/csky/mm/fault.c +++ b/arch/csky/mm/fault.c @@ -183,13 +183,13 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, bad_area_nosemaphore: /* User mode accesses just cause a SIGSEGV */ if (user_mode(regs)) { - tsk->thread.trap_no = (regs->sr >> 16) & 0xff; + tsk->thread.trap_no = trap_no(regs); force_sig_fault(SIGSEGV, si_code, (void __user *)address); return; } no_context: - tsk->thread.trap_no = (regs->sr >> 16) & 0xff; + tsk->thread.trap_no = trap_no(regs); /* Are we prepared to handle this kernel fault? */ if (fixup_exception(regs)) @@ -202,10 +202,10 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, bust_spinlocks(1); pr_alert("Unable to handle kernel paging request at virtual " "address 0x%08lx, pc: 0x%08lx\n", address, regs->pc); - die_if_kernel("Oops", regs, write); + die(regs, "Oops"); out_of_memory: - tsk->thread.trap_no = (regs->sr >> 16) & 0xff; + tsk->thread.trap_no = trap_no(regs); /* * We ran out of memory, call the OOM killer, and return the userspace @@ -215,7 +215,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, return; do_sigbus: - tsk->thread.trap_no = (regs->sr >> 16) & 0xff; + tsk->thread.trap_no = trap_no(regs); mmap_read_unlock(mm);