Commit dcb30e65 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64 

Pull ARM64 fixes from Catalin Marinas:
 - Compat register fault reporting fix
 - Documentation clarification on tagged pointers
 - hwcap widened to 64-bit (user space already reading it as 64-bit)

* tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
  arm64: Widen hwcap to be 64 bit
  arm64: Correctly report LR and SP for compat tasks
  arm64: documentation: tighten up tagged pointer documentation
  arm64: Make do_bad_area() function static
parents 7b9e3a6a 25804e6a

Documentation/arm64/tagged-pointers.txt

+7 −7
Original line number Diff line number Diff line
@@ -18,17 +18,17 @@ this byte for application use, with the following caveats: 
	    parameters containing user virtual addresses *must* have

	    their top byte cleared before trapping to the kernel.



	(2) Tags are not guaranteed to be preserved when delivering

	    signals. This means that signal handlers in applications

	    making use of tags cannot rely on the tag information for

	    user virtual addresses being maintained for fields inside

	    siginfo_t. One exception to this rule is for signals raised

	    in response to debug exceptions, where the tag information

	(2) Non-zero tags are not preserved when delivering signals.

	    This means that signal handlers in applications making use

	    of tags cannot rely on the tag information for user virtual

	    addresses being maintained for fields inside siginfo_t.

	    One exception to this rule is for signals raised in response

	    to watchpoint debug exceptions, where the tag information

	    will be preserved.



	(3) Special care should be taken when using tagged pointers,

	    since it is likely that C compilers will not hazard two

	    addresses differing only in the upper bits.

	    virtual addresses differing only in the upper byte.



The architecture prevents the use of a tagged PC, so the upper byte will

be set to a sign-extension of bit 55 on exception return.

arch/arm64/include/asm/hwcap.h

+1 −1
Original line number Diff line number Diff line
@@ -43,6 +43,6 @@ 
				 COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\

				 COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV)



extern unsigned int elf_hwcap;

extern unsigned long elf_hwcap;

#endif

#endif

arch/arm64/kernel/process.c

+16 −5
Original line number Diff line number Diff line
@@ -143,15 +143,26 @@ void machine_restart(char *cmd) 


void __show_regs(struct pt_regs *regs)

{

	int i;

	int i, top_reg;

	u64 lr, sp;



	if (compat_user_mode(regs)) {

		lr = regs->compat_lr;

		sp = regs->compat_sp;

		top_reg = 12;

	} else {

		lr = regs->regs[30];

		sp = regs->sp;

		top_reg = 29;

	}



	show_regs_print_info(KERN_DEFAULT);

	print_symbol("PC is at %s\n", instruction_pointer(regs));

	print_symbol("LR is at %s\n", regs->regs[30]);

	print_symbol("LR is at %s\n", lr);

	printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",

	       regs->pc, regs->regs[30], regs->pstate);

	printk("sp : %016llx\n", regs->sp);

	for (i = 29; i >= 0; i--) {

	       regs->pc, lr, regs->pstate);

	printk("sp : %016llx\n", sp);

	for (i = top_reg; i >= 0; i--) {

		printk("x%-2d: %016llx ", i, regs->regs[i]);

		if (i % 2 == 0)

			printk("\n");

arch/arm64/kernel/setup.c

+1 −1
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ 
unsigned int processor_id;

EXPORT_SYMBOL(processor_id);



unsigned int elf_hwcap __read_mostly;

unsigned long elf_hwcap __read_mostly;

EXPORT_SYMBOL_GPL(elf_hwcap);



static const char *cpu_name;

arch/arm64/mm/fault.c

+1 −1
Original line number Diff line number Diff line
@@ -130,7 +130,7 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr, 
	force_sig_info(sig, &si, tsk);

}



void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)

static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)

{

	struct task_struct *tsk = current;

	struct mm_struct *mm = tsk->active_mm;

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