Commit 8efa3c9d authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

uml: eliminate setjmp_wrapper 



setjmp_wrapper existed to provide setjmp to kernel code when UML used libc's
setjmp and longjmp.  Now that UML has its own implementation, this isn't
needed and kernel code can invoke setjmp directly.

do_buffer_op is massively cleaned up since it is no longer a callback from
setjmp_wrapper and given a va_list from which it must extract its arguments.

The actual setjmp is moved from buffer_op to do_op_one_page because the copy
operation is inside an atomic section (kmap_atomic to kunmap_atomic) and it
shouldn't be longjmp-ed out of.

Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0b4e273f

arch/um/include/os.h

+0 −1
Original line number Diff line number Diff line
@@ -235,7 +235,6 @@ extern void stack_protections(unsigned long address); 
extern int raw(int fd);

extern void setup_machinename(char *machine_out);

extern void setup_hostinfo(char *buf, int len);

extern int setjmp_wrapper(void (*proc)(void *, void *), ...);

extern void os_dump_core(void) __attribute__ ((noreturn));



/* time.c */

arch/um/kernel/skas/uaccess.c

+27 −46
Original line number Diff line number Diff line
@@ -58,9 +58,10 @@ static pte_t *maybe_map(unsigned long virt, int is_write) 
static int do_op_one_page(unsigned long addr, int len, int is_write,

		 int (*op)(unsigned long addr, int len, void *arg), void *arg)

{

	jmp_buf buf;

	struct page *page;

	pte_t *pte;

	int n;

	int n, faulted;



	pte = maybe_map(addr, is_write);

	if (pte == NULL)
@@ -70,82 +71,62 @@ static int do_op_one_page(unsigned long addr, int len, int is_write, 
	addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) +

		(addr & ~PAGE_MASK);



	current->thread.fault_catcher = &buf;



	faulted = UML_SETJMP(&buf);

	if (faulted == 0)

		n = (*op)(addr, len, arg);

	else

		n = -1;



	current->thread.fault_catcher = NULL;



	kunmap_atomic(page, KM_UML_USERCOPY);



	return n;

}



static void do_buffer_op(void *jmpbuf, void *arg_ptr)

static int buffer_op(unsigned long addr, int len, int is_write,

		     int (*op)(unsigned long, int, void *), void *arg)

{

	va_list args;

	unsigned long addr;

	int len, is_write, size, remain, n;

	int (*op)(unsigned long, int, void *);

	void *arg;

	int *res;



	va_copy(args, *(va_list *)arg_ptr);

	addr = va_arg(args, unsigned long);

	len = va_arg(args, int);

	is_write = va_arg(args, int);

	op = va_arg(args, void *);

	arg = va_arg(args, void *);

	res = va_arg(args, int *);

	va_end(args);

	int size, remain, n;



	size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len);

	remain = len;



	current->thread.fault_catcher = jmpbuf;

	n = do_op_one_page(addr, size, is_write, op, arg);

	if (n != 0) {

		*res = (n < 0 ? remain : 0);

		remain = (n < 0 ? remain : 0);

		goto out;

	}



	addr += size;

	remain -= size;

	if (remain == 0) {

		*res = 0;

	if (remain == 0)

		goto out;

	}



	while (addr < ((addr + remain) & PAGE_MASK)) {

		n = do_op_one_page(addr, PAGE_SIZE, is_write, op, arg);

		if (n != 0) {

			*res = (n < 0 ? remain : 0);

			remain = (n < 0 ? remain : 0);

			goto out;

		}



		addr += PAGE_SIZE;

		remain -= PAGE_SIZE;

	}

	if (remain == 0) {

		*res = 0;

	if (remain == 0)

		goto out;

	}



	n = do_op_one_page(addr, remain, is_write, op, arg);

	if (n != 0)

		*res = (n < 0 ? remain : 0);

	else *res = 0;

 out:

	current->thread.fault_catcher = NULL;

	if (n != 0) {

		remain = (n < 0 ? remain : 0);

		goto out;

	}



static int buffer_op(unsigned long addr, int len, int is_write,

		     int (*op)(unsigned long addr, int len, void *arg),

		     void *arg)

{

	int faulted, res;



	faulted = setjmp_wrapper(do_buffer_op, addr, len, is_write, op, arg,

				 &res);

	if (!faulted)

		return res;



	return addr + len - (unsigned long) current->thread.fault_addr;

	return 0;

 out:

	return remain;

}



static int copy_chunk_from_user(unsigned long from, int len, void *arg)

arch/um/os-Linux/util.c

+0 −15
Original line number Diff line number Diff line
@@ -88,21 +88,6 @@ void setup_hostinfo(char *buf, int len) 
		 host.release, host.version, host.machine);

}



int setjmp_wrapper(void (*proc)(void *, void *), ...)

{

	va_list args;

	jmp_buf buf;

	int n;



	n = UML_SETJMP(&buf);

	if(n == 0){

		va_start(args, proc);

		(*proc)(&buf, &args);

	}

	va_end(args);

	return n;

}



void os_dump_core(void)

{

	int pid;

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