Commit 5bc46ce2 authored by Guo Ren's avatar Guo Ren
Browse files

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: default avatarGuo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
parent 71e193d7

arch/csky/include/asm/bug.h

+2 −1
Original line number Diff line number Diff line
@@ -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 */

arch/csky/include/asm/ptrace.h

+1 −0
Original line number Diff line number Diff line
@@ -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)

arch/csky/kernel/ptrace.c

+2 −27
Original line number Diff line number Diff line
@@ -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;

}

arch/csky/kernel/traps.c

+147 −76
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
#include <linux/rtc.h>

#include <linux/uaccess.h>

#include <linux/kprobes.h>

#include <linux/kdebug.h>

#include <linux/sched/debug.h>



#include <asm/setup.h>

#include <asm/traps.h>
@@ -27,6 +29,8 @@ 
#include <abi/fpu.h>

#endif



int show_unhandled_signals = 1;



/* Defined in entry.S */

asmlinkage void csky_trap(void);
@@ -77,55 +81,94 @@ 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);

	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;
@@ -134,11 +177,19 @@ asmlinkage void trap_c(struct pt_regs *regs) 
	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;
@@ -147,47 +198,67 @@ asmlinkage void trap_c(struct pt_regs *regs) 
	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



	do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc,

		      "Oops - illegal instruction exception");

}



asmlinkage void do_trap_fpe(struct pt_regs *regs)

{

			sig = SIGILL;

			break;

#ifdef CONFIG_CPU_HAS_FP

	return fpu_fpe(regs);

#else

	do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc,

		      "Oops - fpu instruction exception");

#endif

}

	/* gdbserver  breakpoint */



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);

}

arch/csky/mm/fault.c

+5 −5
Original line number Diff line number Diff line
@@ -183,13 +183,13 @@ bad_area: 
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 @@ no_context: 
	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 @@ out_of_memory: 
	return;



do_sigbus:

	tsk->thread.trap_no = (regs->sr >> 16) & 0xff;

	tsk->thread.trap_no = trap_no(regs);



	mmap_read_unlock(mm);

CRA Git | Maintained and supported by SUSTech CRA and CCSE