Commit def0bfdb authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc: use probe_user_read() and probe_user_write() 



Instead of opencoding, use probe_user_read() to failessly read
a user location and probe_user_write() for writing to user.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e041f5eedb23f09ab553be8a91c3de2087147320.1579800517.git.christophe.leroy@c-s.fr
parent 1e353198

arch/powerpc/kernel/process.c

+1 −11
Original line number Diff line number Diff line
@@ -1277,16 +1277,6 @@ void show_user_instructions(struct pt_regs *regs) 


	pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));



	/*

	 * Make sure the NIP points at userspace, not kernel text/data or

	 * elsewhere.

	 */

	if (!__access_ok(pc, NR_INSN_TO_PRINT * sizeof(int), USER_DS)) {

		pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",

			current->comm, current->pid);

		return;

	}



	seq_buf_init(&s, buf, sizeof(buf));



	while (n) {
@@ -1297,7 +1287,7 @@ void show_user_instructions(struct pt_regs *regs) 
		for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {

			int instr;



			if (probe_kernel_address((const void *)pc, instr)) {

			if (probe_user_read(&instr, (void __user *)pc, sizeof(instr))) {

				seq_buf_printf(&s, "XXXXXXXX ");

				continue;

			}

arch/powerpc/kvm/book3s_64_mmu_radix.c

+2 −4
Original line number Diff line number Diff line
@@ -63,12 +63,10 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, 
	}

	isync();



	pagefault_disable();

	if (is_load)

		ret = raw_copy_from_user(to, from, n);

		ret = probe_user_read(to, (const void __user *)from, n);

	else

		ret = raw_copy_to_user(to, from, n);

	pagefault_enable();

		ret = probe_user_write((void __user *)to, from, n);



	/* switch the pid first to avoid running host with unallocated pid */

	if (quadrant == 1 && pid != old_pid)

arch/powerpc/mm/fault.c

+1 −5
Original line number Diff line number Diff line
@@ -279,12 +279,8 @@ static bool bad_stack_expansion(struct pt_regs *regs, unsigned long address, 
		if ((flags & FAULT_FLAG_WRITE) && (flags & FAULT_FLAG_USER) &&

		    access_ok(nip, sizeof(*nip))) {

			unsigned int inst;

			int res;



			pagefault_disable();

			res = __get_user_inatomic(inst, nip);

			pagefault_enable();

			if (!res)

			if (!probe_user_read(&inst, nip, sizeof(inst)))

				return !store_updates_sp(inst);

			*must_retry = true;

		}

arch/powerpc/oprofile/backtrace.c

+2 −12
Original line number Diff line number Diff line
@@ -28,15 +28,12 @@ static unsigned int user_getsp32(unsigned int sp, int is_first) 
	unsigned int stack_frame[2];

	void __user *p = compat_ptr(sp);



	if (!access_ok(p, sizeof(stack_frame)))

		return 0;



	/*

	 * The most likely reason for this is that we returned -EFAULT,

	 * which means that we've done all that we can do from

	 * interrupt context.

	 */

	if (__copy_from_user_inatomic(stack_frame, p, sizeof(stack_frame)))

	if (probe_user_read(stack_frame, (void __user *)p, sizeof(stack_frame)))

		return 0;



	if (!is_first)
@@ -54,11 +51,7 @@ static unsigned long user_getsp64(unsigned long sp, int is_first) 
{

	unsigned long stack_frame[3];



	if (!access_ok((void __user *)sp, sizeof(stack_frame)))

		return 0;



	if (__copy_from_user_inatomic(stack_frame, (void __user *)sp,

					sizeof(stack_frame)))

	if (probe_user_read(stack_frame, (void __user *)sp, sizeof(stack_frame)))

		return 0;



	if (!is_first)
@@ -103,7 +96,6 @@ void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth) 
			first_frame = 0;

		}

	} else {

		pagefault_disable();

#ifdef CONFIG_PPC64

		if (!is_32bit_task()) {

			while (depth--) {
@@ -112,7 +104,6 @@ void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth) 
					break;

				first_frame = 0;

			}

			pagefault_enable();

			return;

		}

#endif
@@ -123,6 +114,5 @@ void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth) 
				break;

			first_frame = 0;

		}

		pagefault_enable();

	}

}

arch/powerpc/perf/callchain.c

+3 −17
Original line number Diff line number Diff line
@@ -155,12 +155,8 @@ static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret) 
	    ((unsigned long)ptr & 7))

		return -EFAULT;



	pagefault_disable();

	if (!__get_user_inatomic(*ret, ptr)) {

		pagefault_enable();

	if (!probe_user_read(ret, ptr, sizeof(*ret)))

		return 0;

	}

	pagefault_enable();



	return read_user_stack_slow(ptr, ret, 8);

}
@@ -171,12 +167,8 @@ static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret) 
	    ((unsigned long)ptr & 3))

		return -EFAULT;



	pagefault_disable();

	if (!__get_user_inatomic(*ret, ptr)) {

		pagefault_enable();

	if (!probe_user_read(ret, ptr, sizeof(*ret)))

		return 0;

	}

	pagefault_enable();



	return read_user_stack_slow(ptr, ret, 4);

}
@@ -293,17 +285,11 @@ static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry, 
 */

static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)

{

	int rc;



	if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||

	    ((unsigned long)ptr & 3))

		return -EFAULT;



	pagefault_disable();

	rc = __get_user_inatomic(*ret, ptr);

	pagefault_enable();



	return rc;

	return probe_user_read(ret, ptr, sizeof(*ret));

}



static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,

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