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Commit 5ded8871 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux 

Pull arm64 fixes from Will Deacon:
 "The main thing is a fix to our FUTEX_WAKE_OP implementation which was
  unbelievably broken, but did actually work for the one scenario that
  GLIBC used to use.

  Summary:

   - Fix stack unwinding so we ignore user stacks

   - Fix ftrace module PLT trampoline initialisation checks

   - Fix terminally broken implementation of FUTEX_WAKE_OP atomics"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value
  arm64: backtrace: Don't bother trying to unwind the userspace stack
  arm64/ftrace: fix inadvertent BUG() in trampoline check
parents 6d0a5984 045afc24

arch/arm64/include/asm/futex.h

+8 −8
Original line number Diff line number Diff line
@@ -30,8 +30,8 @@ do { \ 
"	prfm	pstl1strm, %2\n"					\

"1:	ldxr	%w1, %2\n"						\

	insn "\n"							\

"2:	stlxr	%w3, %w0, %2\n"						\

"	cbnz	%w3, 1b\n"						\

"2:	stlxr	%w0, %w3, %2\n"						\

"	cbnz	%w0, 1b\n"						\

"	dmb	ish\n"							\

"3:\n"									\

"	.pushsection .fixup,\"ax\"\n"					\
@@ -50,30 +50,30 @@ do { \ 
static inline int

arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *_uaddr)

{

	int oldval = 0, ret, tmp;

	int oldval, ret, tmp;

	u32 __user *uaddr = __uaccess_mask_ptr(_uaddr);



	pagefault_disable();



	switch (op) {

	case FUTEX_OP_SET:

		__futex_atomic_op("mov	%w0, %w4",

		__futex_atomic_op("mov	%w3, %w4",

				  ret, oldval, uaddr, tmp, oparg);

		break;

	case FUTEX_OP_ADD:

		__futex_atomic_op("add	%w0, %w1, %w4",

		__futex_atomic_op("add	%w3, %w1, %w4",

				  ret, oldval, uaddr, tmp, oparg);

		break;

	case FUTEX_OP_OR:

		__futex_atomic_op("orr	%w0, %w1, %w4",

		__futex_atomic_op("orr	%w3, %w1, %w4",

				  ret, oldval, uaddr, tmp, oparg);

		break;

	case FUTEX_OP_ANDN:

		__futex_atomic_op("and	%w0, %w1, %w4",

		__futex_atomic_op("and	%w3, %w1, %w4",

				  ret, oldval, uaddr, tmp, ~oparg);

		break;

	case FUTEX_OP_XOR:

		__futex_atomic_op("eor	%w0, %w1, %w4",

		__futex_atomic_op("eor	%w3, %w1, %w4",

				  ret, oldval, uaddr, tmp, oparg);

		break;

	default:

arch/arm64/include/asm/module.h

+5 −0
Original line number Diff line number Diff line
@@ -73,4 +73,9 @@ static inline bool is_forbidden_offset_for_adrp(void *place) 
struct plt_entry get_plt_entry(u64 dst, void *pc);

bool plt_entries_equal(const struct plt_entry *a, const struct plt_entry *b);



static inline bool plt_entry_is_initialized(const struct plt_entry *e)

{

	return e->adrp || e->add || e->br;

}



#endif /* __ASM_MODULE_H */

arch/arm64/kernel/ftrace.c

+1 −2
Original line number Diff line number Diff line
@@ -107,8 +107,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) 
		trampoline = get_plt_entry(addr, mod->arch.ftrace_trampoline);

		if (!plt_entries_equal(mod->arch.ftrace_trampoline,

				       &trampoline)) {

			if (!plt_entries_equal(mod->arch.ftrace_trampoline,

					       &(struct plt_entry){})) {

			if (plt_entry_is_initialized(mod->arch.ftrace_trampoline)) {

				pr_err("ftrace: far branches to multiple entry points unsupported inside a single module\n");

				return -EINVAL;

			}

arch/arm64/kernel/traps.c

+9 −6
Original line number Diff line number Diff line
@@ -102,10 +102,16 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) 
void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)

{

	struct stackframe frame;

	int skip;

	int skip = 0;



	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);



	if (regs) {

		if (user_mode(regs))

			return;

		skip = 1;

	}



	if (!tsk)

		tsk = current;
@@ -126,7 +132,6 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) 
	frame.graph = 0;

#endif



	skip = !!regs;

	printk("Call trace:\n");

	do {

		/* skip until specified stack frame */
@@ -176,15 +181,13 @@ static int __die(const char *str, int err, struct pt_regs *regs) 
		return ret;



	print_modules();

	__show_regs(regs);

	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",

		 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),

		 end_of_stack(tsk));

	show_regs(regs);



	if (!user_mode(regs)) {

		dump_backtrace(regs, tsk);

	if (!user_mode(regs))

		dump_instr(KERN_EMERG, regs);

	}



	return ret;

}