Commit f43a54a0 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

signal/mips: Use force_sig_fault where appropriate 



Filling in struct siginfo before calling force_sig_info a tedious and
error prone process, where once in a great while the wrong fields
are filled out, and siginfo has been inconsistently cleared.

Simplify this process by using the helper force_sig_fault.  Which
takes as a parameters all of the information it needs, ensures
all of the fiddly bits of filling in struct siginfo are done properly
and then calls force_sig_info.

In short about a 5 line reduction in code for every time force_sig_info
is called, which makes the calling function clearer.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent 6f467986

arch/mips/kernel/traps.c

+18 −47
Original line number Diff line number Diff line
@@ -699,17 +699,11 @@ static int simulate_sync(struct pt_regs *regs, unsigned int opcode) 
asmlinkage void do_ov(struct pt_regs *regs)

{

	enum ctx_state prev_state;

	siginfo_t info;



	clear_siginfo(&info);

	info.si_signo = SIGFPE;

	info.si_code = FPE_INTOVF;

	info.si_addr = (void __user *)regs->cp0_epc;



	prev_state = exception_enter();

	die_if_kernel("Integer overflow", regs);



	force_sig_info(SIGFPE, &info, current);

	force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->cp0_epc, current);

	exception_exit(prev_state);

}
@@ -722,32 +716,27 @@ asmlinkage void do_ov(struct pt_regs *regs) 
void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,

		     struct task_struct *tsk)

{

	struct siginfo si;



	clear_siginfo(&si);

	si.si_addr = fault_addr;

	si.si_signo = SIGFPE;

	int si_code;



	if (fcr31 & FPU_CSR_INV_X)

		si.si_code = FPE_FLTINV;

		si_code = FPE_FLTINV;

	else if (fcr31 & FPU_CSR_DIV_X)

		si.si_code = FPE_FLTDIV;

		si_code = FPE_FLTDIV;

	else if (fcr31 & FPU_CSR_OVF_X)

		si.si_code = FPE_FLTOVF;

		si_code = FPE_FLTOVF;

	else if (fcr31 & FPU_CSR_UDF_X)

		si.si_code = FPE_FLTUND;

		si_code = FPE_FLTUND;

	else if (fcr31 & FPU_CSR_INE_X)

		si.si_code = FPE_FLTRES;

		si_code = FPE_FLTRES;



	force_sig_info(SIGFPE, &si, tsk);

	force_sig_fault(SIGFPE, si_code, fault_addr, tsk);

}



int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)

{

	struct siginfo si;

	int si_code;

	struct vm_area_struct *vma;



	clear_siginfo(&si);

	switch (sig) {

	case 0:

		return 0;
@@ -757,23 +746,18 @@ int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31) 
		return 1;



	case SIGBUS:

		si.si_addr = fault_addr;

		si.si_signo = sig;

		si.si_code = BUS_ADRERR;

		force_sig_info(sig, &si, current);

		force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr, current);

		return 1;



	case SIGSEGV:

		si.si_addr = fault_addr;

		si.si_signo = sig;

		down_read(&current->mm->mmap_sem);

		vma = find_vma(current->mm, (unsigned long)fault_addr);

		if (vma && (vma->vm_start <= (unsigned long)fault_addr))

			si.si_code = SEGV_ACCERR;

			si_code = SEGV_ACCERR;

		else

			si.si_code = SEGV_MAPERR;

			si_code = SEGV_MAPERR;

		up_read(&current->mm->mmap_sem);

		force_sig_info(sig, &si, current);

		force_sig_fault(SIGSEGV, si_code, fault_addr, current);

		return 1;



	default:
@@ -896,10 +880,8 @@ out: 
void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,

	const char *str)

{

	siginfo_t info;

	char b[40];



	clear_siginfo(&info);

#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP

	if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr,

			 SIGTRAP) == NOTIFY_STOP)
@@ -921,13 +903,9 @@ void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code, 
	case BRK_DIVZERO:

		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);

		die_if_kernel(b, regs);

		if (code == BRK_DIVZERO)

			info.si_code = FPE_INTDIV;

		else

			info.si_code = FPE_INTOVF;

		info.si_signo = SIGFPE;

		info.si_addr = (void __user *) regs->cp0_epc;

		force_sig_info(SIGFPE, &info, current);

		force_sig_fault(SIGFPE,

				code == BRK_DIVZERO ? FPE_INTDIV : FPE_INTOVF,

				(void __user *) regs->cp0_epc, current);

		break;

	case BRK_BUG:

		die_if_kernel("Kernel bug detected", regs);
@@ -952,9 +930,7 @@ void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code, 
		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);

		die_if_kernel(b, regs);

		if (si_code) {

			info.si_signo = SIGTRAP;

			info.si_code = si_code;

			force_sig_info(SIGTRAP, &info, current);

			force_sig_fault(SIGTRAP, si_code, NULL,	current);

		} else {

			force_sig(SIGTRAP, current);

		}
@@ -1506,13 +1482,8 @@ asmlinkage void do_mdmx(struct pt_regs *regs) 
 */

asmlinkage void do_watch(struct pt_regs *regs)

{

	siginfo_t info;

	enum ctx_state prev_state;



	clear_siginfo(&info);

	info.si_signo = SIGTRAP;

	info.si_code = TRAP_HWBKPT;



	prev_state = exception_enter();

	/*

	 * Clear WP (bit 22) bit of cause register so we don't loop
@@ -1528,7 +1499,7 @@ asmlinkage void do_watch(struct pt_regs *regs) 
	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {

		mips_read_watch_registers();

		local_irq_enable();

		force_sig_info(SIGTRAP, &info, current);

		force_sig_fault(SIGTRAP, TRAP_HWBKPT, NULL, current);

	} else {

		mips_clear_watch_registers();

		local_irq_enable();

arch/mips/mm/fault.c

+5 −14
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, 
	struct task_struct *tsk = current;

	struct mm_struct *mm = tsk->mm;

	const int field = sizeof(unsigned long) * 2;

	siginfo_t info;

	int si_code;

	int fault;

	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
@@ -63,8 +63,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, 
		return;

#endif



	clear_siginfo(&info);

	info.si_code = SEGV_MAPERR;

	si_code = SEGV_MAPERR;



	/*

	 * We fault-in kernel-space virtual memory on-demand. The
@@ -113,7 +112,7 @@ retry: 
 * we can handle it..

 */

good_area:

	info.si_code = SEGV_ACCERR;

	si_code = SEGV_ACCERR;



	if (write) {

		if (!(vma->vm_flags & VM_WRITE))
@@ -224,11 +223,7 @@ bad_area_nosemaphore: 
			pr_cont("\n");

		}

		current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;

		info.si_signo = SIGSEGV;

		info.si_errno = 0;

		/* info.si_code has been set above */

		info.si_addr = (void __user *) address;

		force_sig_info(SIGSEGV, &info, tsk);

		force_sig_fault(SIGSEGV, si_code, (void __user *)address, tsk);

		return;

	}
@@ -284,11 +279,7 @@ do_sigbus: 
#endif

	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;

	tsk->thread.cp0_badvaddr = address;

	info.si_signo = SIGBUS;

	info.si_errno = 0;

	info.si_code = BUS_ADRERR;

	info.si_addr = (void __user *) address;

	force_sig_info(SIGBUS, &info, tsk);

	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, tsk);



	return;

#ifndef CONFIG_64BIT

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