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Commit c449c38b authored by David S. Miller's avatar David S. Miller
Browse files

[SPARC64]: Unaligned accesses to userspace are hard errors. 



Userspace is forbidden from making unaligned loads and
stores.  So if we get an unaligned trap due to a
{get,put}_user(), signal a fault and run the exception
handler.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6e7726e1

arch/sparc64/kernel/unaligned.c

+31 −13
Original line number Diff line number Diff line
@@ -243,7 +243,7 @@ static inline int ok_for_kernel(unsigned int insn) 
	return !floating_point_load_or_store_p(insn);

}



static void kernel_mna_trap_fault(void)

static void kernel_mna_trap_fault(int fixup_tstate_asi)

{

	struct pt_regs *regs = current_thread_info()->kern_una_regs;

	unsigned int insn = current_thread_info()->kern_una_insn;
@@ -274,18 +274,15 @@ static void kernel_mna_trap_fault(void) 
	regs->tpc = entry->fixup;

	regs->tnpc = regs->tpc + 4;



	if (fixup_tstate_asi) {

		regs->tstate &= ~TSTATE_ASI;

		regs->tstate |= (ASI_AIUS << 24UL);

	}

}



asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)

static void log_unaligned(struct pt_regs *regs)

{

	static unsigned long count, last_time;

	enum direction dir = decode_direction(insn);

	int size = decode_access_size(insn);



	current_thread_info()->kern_una_regs = regs;

	current_thread_info()->kern_una_insn = insn;



	if (jiffies - last_time > 5 * HZ)

		count = 0;
@@ -295,6 +292,28 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn) 
		printk("Kernel unaligned access at TPC[%lx] ", regs->tpc);

		print_symbol("%s\n", regs->tpc);

	}

}



asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)

{

	enum direction dir = decode_direction(insn);

	int size = decode_access_size(insn);

	int orig_asi, asi;



	current_thread_info()->kern_una_regs = regs;

	current_thread_info()->kern_una_insn = insn;



	orig_asi = asi = decode_asi(insn, regs);



	/* If this is a {get,put}_user() on an unaligned userspace pointer,

	 * just signal a fault and do not log the event.

	 */

	if (asi == ASI_AIUS) {

		kernel_mna_trap_fault(0);

		return;

	}



	log_unaligned(regs);



	if (!ok_for_kernel(insn) || dir == both) {

		printk("Unsupported unaligned load/store trap for kernel "
@@ -302,10 +321,10 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn) 
		unaligned_panic("Kernel does fpu/atomic "

				"unaligned load/store.", regs);



		kernel_mna_trap_fault();

		kernel_mna_trap_fault(0);

	} else {

		unsigned long addr, *reg_addr;

		int orig_asi, asi, err;

		int err;



		addr = compute_effective_address(regs, insn,

						 ((insn >> 25) & 0x1f));
@@ -315,7 +334,6 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn) 
		       regs->tpc, dirstrings[dir], addr, size,

		       regs->u_regs[UREG_RETPC]);

#endif

		orig_asi = asi = decode_asi(insn, regs);

		switch (asi) {

		case ASI_NL:

		case ASI_AIUPL:
@@ -365,7 +383,7 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn) 
			/* Not reached... */

		}

		if (unlikely(err))

			kernel_mna_trap_fault();

			kernel_mna_trap_fault(1);

		else

			advance(regs);

	}