Commit a2d25a53 authored by Vladimir Murzin's avatar Vladimir Murzin Committed by Will Deacon
Browse files

arm64: compat: align cacheflush syscall with arch/arm 



Update handling of cacheflush syscall with changes made in arch/arm
counterpart:
 - return error to userspace when flushing syscall fails
 - split user cache-flushing into interruptible chunks
 - don't bother rounding to nearest vma

Signed-off-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
[will: changed internal return value from -EINTR to 0 to match arch/arm/]
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent a1ae65b2

arch/arm64/include/asm/cacheflush.h

+1 −1
Original line number Diff line number Diff line
@@ -73,7 +73,7 @@ extern void flush_cache_all(void); 
extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);

extern void flush_icache_range(unsigned long start, unsigned long end);

extern void __flush_dcache_area(void *addr, size_t len);

extern void __flush_cache_user_range(unsigned long start, unsigned long end);

extern long __flush_cache_user_range(unsigned long start, unsigned long end);



static inline void flush_cache_mm(struct mm_struct *mm)

{

arch/arm64/kernel/sys_compat.c

+29 −20
Original line number Diff line number Diff line
@@ -28,29 +28,39 @@ 
#include <asm/cacheflush.h>

#include <asm/unistd.h>



static inline void

do_compat_cache_op(unsigned long start, unsigned long end, int flags)

static long

__do_compat_cache_op(unsigned long start, unsigned long end)

{

	struct mm_struct *mm = current->active_mm;

	struct vm_area_struct *vma;

	long ret;



	if (end < start || flags)

		return;

	do {

		unsigned long chunk = min(PAGE_SIZE, end - start);



	down_read(&mm->mmap_sem);

	vma = find_vma(mm, start);

	if (vma && vma->vm_start < end) {

		if (start < vma->vm_start)

			start = vma->vm_start;

		if (end > vma->vm_end)

			end = vma->vm_end;

		up_read(&mm->mmap_sem);

		__flush_cache_user_range(start & PAGE_MASK, PAGE_ALIGN(end));

		return;

	}

	up_read(&mm->mmap_sem);

		if (fatal_signal_pending(current))

			return 0;



		ret = __flush_cache_user_range(start, start + chunk);

		if (ret)

			return ret;



		cond_resched();

		start += chunk;

	} while (start < end);



	return 0;

}



static inline long

do_compat_cache_op(unsigned long start, unsigned long end, int flags)

{

	if (end < start || flags)

		return -EINVAL;



	if (!access_ok(VERIFY_READ, start, end - start))

		return -EFAULT;



	return __do_compat_cache_op(start, end);

}

/*

 * Handle all unrecognised system calls.

 */
@@ -74,8 +84,7 @@ long compat_arm_syscall(struct pt_regs *regs) 
	 * the specified region).

	 */

	case __ARM_NR_compat_cacheflush:

		do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]);

		return 0;

		return do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]);



	case __ARM_NR_compat_set_tls:

		current->thread.tp_value = regs->regs[0];

arch/arm64/mm/cache.S

+5 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#include <linux/errno.h>

#include <linux/linkage.h>

#include <linux/init.h>

#include <asm/assembler.h>
@@ -140,9 +141,12 @@ USER(9f, ic ivau, x4 ) // invalidate I line PoU 
	add	x4, x4, x2

	cmp	x4, x1

	b.lo	1b

9:						// ignore any faulting cache operation

	dsb	ish

	isb

	mov	x0, #0

	ret

9:

	mov	x0, #-EFAULT

	ret

ENDPROC(flush_icache_range)

ENDPROC(__flush_cache_user_range)

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