Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5669ccee authored by Oleg Nesterov's avatar Oleg Nesterov
Browse files

uprobes: Introduce copy_to_page() 



Extract the kmap_atomic/memcpy/kunmap_atomic code from
xol_get_insn_slot() into the new simple helper, copy_to_page().
It will have more users soon.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarAnton Arapov <anton@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
parent 98763a1b

kernel/events/uprobes.c

+8 −6
Original line number Original line Diff line number Diff line
@@ -194,6 +194,13 @@ static void copy_from_page(struct page *page, unsigned long vaddr, void *dst, in 
	kunmap_atomic(kaddr);

	kunmap_atomic(kaddr);

}

}





static void copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len)

{

	void *kaddr = kmap_atomic(page);

	memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len);

	kunmap_atomic(kaddr);

}



static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode)

static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode)

{

{

	uprobe_opcode_t old_opcode;

	uprobe_opcode_t old_opcode;
@@ -1227,9 +1234,7 @@ static unsigned long xol_take_insn_slot(struct xol_area *area) 
static unsigned long xol_get_insn_slot(struct uprobe *uprobe)

static unsigned long xol_get_insn_slot(struct uprobe *uprobe)

{

{

	struct xol_area *area;

	struct xol_area *area;

	unsigned long offset;

	unsigned long xol_vaddr;

	unsigned long xol_vaddr;

	void *vaddr;





	area = get_xol_area();

	area = get_xol_area();

	if (!area)

	if (!area)
@@ -1240,10 +1245,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe) 
		return 0;

		return 0;





	/* Initialize the slot */

	/* Initialize the slot */

	offset = xol_vaddr & ~PAGE_MASK;

	copy_to_page(area->page, xol_vaddr, uprobe->arch.insn, MAX_UINSN_BYTES);

	vaddr = kmap_atomic(area->page);

	memcpy(vaddr + offset, uprobe->arch.insn, MAX_UINSN_BYTES);

	kunmap_atomic(vaddr);

	/*

	/*

	 * We probably need flush_icache_user_range() but it needs vma.

	 * We probably need flush_icache_user_range() but it needs vma.

	 * This should work on supported architectures too.

	 * This should work on supported architectures too.