#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/export.h>
#include <asm/syscall.h>

static int collect_syscall(struct task_struct *target, long *callno,
			   unsigned long args[6], unsigned int maxargs,
			   unsigned long *sp, unsigned long *pc)
{
	struct pt_regs *regs;

	if (!try_get_task_stack(target)) {
		/* Task has no stack, so the task isn't in a syscall. */
		*callno = -1;
		return 0;
	}

	regs = task_pt_regs(target);
	if (unlikely(!regs)) {
		put_task_stack(target);
		return -EAGAIN;
	}

	*sp = user_stack_pointer(regs);
	*pc = instruction_pointer(regs);

	*callno = syscall_get_nr(target, regs);
	if (*callno != -1L && maxargs > 0)
		syscall_get_arguments(target, regs, 0, maxargs, args);

	put_task_stack(target);
	return 0;
}

/**
 * task_current_syscall - Discover what a blocked task is doing.
 * @target:		thread to examine
 * @callno:		filled with system call number or -1
 * @args:		filled with @maxargs system call arguments
 * @maxargs:		number of elements in @args to fill
 * @sp:			filled with user stack pointer
 * @pc:			filled with user PC
 *
 * If @target is blocked in a system call, returns zero with *@callno
 * set to the the call's number and @args filled in with its arguments.
 * Registers not used for system call arguments may not be available and
 * it is not kosher to use &struct user_regset calls while the system
 * call is still in progress.  Note we may get this result if @target
 * has finished its system call but not yet returned to user mode, such
 * as when it's stopped for signal handling or syscall exit tracing.
 *
 * If @target is blocked in the kernel during a fault or exception,
 * returns zero with *@callno set to -1 and does not fill in @args.
 * If so, it's now safe to examine @target using &struct user_regset
 * get() calls as long as we're sure @target won't return to user mode.
 *
 * Returns -%EAGAIN if @target does not remain blocked.
 *
 * Returns -%EINVAL if @maxargs is too large (maximum is six).
 */
int task_current_syscall(struct task_struct *target, long *callno,
			 unsigned long args[6], unsigned int maxargs,
			 unsigned long *sp, unsigned long *pc)
{
	long state;
	unsigned long ncsw;

	if (unlikely(maxargs > 6))
		return -EINVAL;

	if (target == current)
		return collect_syscall(target, callno, args, maxargs, sp, pc);

	state = target->state;
	if (unlikely(!state))
		return -EAGAIN;

	ncsw = wait_task_inactive(target, state);
	if (unlikely(!ncsw) ||
	    unlikely(collect_syscall(target, callno, args, maxargs, sp, pc)) ||
	    unlikely(wait_task_inactive(target, state) != ncsw))
		return -EAGAIN;

	return 0;
}
ass='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=c92816275674c1491ce228ee49aa030a5fa1be04'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net?id=c92816275674c1491ce228ee49aa030a5fa1be04'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/wireless?id=c92816275674c1491ce228ee49aa030a5fa1be04'>wireless</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/wireless/wext-compat.c?id=c92816275674c1491ce228ee49aa030a5fa1be04'>wext-compat.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='c92816275674c1491ce228ee49aa030a5fa1be04'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-15 12:40:53 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-15 12:40:53 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/wireless/wext-compat.c?id=c92816275674c1491ce228ee49aa030a5fa1be04'>c92816275674c1491ce228ee49aa030a5fa1be04</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/wireless/wext-compat.c?id=c92816275674c1491ce228ee49aa030a5fa1be04'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=c92816275674c1491ce228ee49aa030a5fa1be04'>97deb97f282c6b9f4f58e45a60ea78d1fe31df4e</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/wireless/wext-compat.c?id=c92816275674c1491ce228ee49aa030a5fa1be04'>net/wireless/wext-compat.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/wireless/wext-compat.c?id=2d5a7101a140adcf7a5d8677649847fbb2dd5a2f'>2d5a7101a140adcf7a5d8677649847fbb2dd5a2f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/wireless/wext-compat.c?id=c92816275674c1491ce228ee49aa030a5fa1be04&amp;id2=2d5a7101a140adcf7a5d8677649847fbb2dd5a2f'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/wireless/wext-compat.c?id=c8a6a09c1c617402cc9254b2bc8da359a0347d75'>c8a6a09c1c617402cc9254b2bc8da359a0347d75</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/wireless/wext-compat.c?id=c92816275674c1491ce228ee49aa030a5fa1be04&amp;id2=c8a6a09c1c617402cc9254b2bc8da359a0347d75'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge tag 'char-misc-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc</div><div class='commit-msg'>Pull char/misc driver fixes from Greg KH:
 "Here are some small char/misc driver fixes for 4.10-rc4 that resolve
  some reported issues.

  The MEI driver issue resolves a lot of problems that people have been
  having, as does the mem driver fix. The other minor fixes resolve
  other reported issues.

  All of these have been in linux-next for a while"

* tag 'char-misc-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  vme: Fix wrong pointer utilization in ca91cx42_slave_get
  auxdisplay: fix new ht16k33 build errors
  ppdev: don't print a free'd string
  extcon: return error code on failure
  drivers: char: mem: Fix thinkos in kmem address checks
  mei: bus: enable OS version only for SPT and newer
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=c92816275674c1491ce228ee49aa030a5fa1be04'>Diffstat</a> (limited to 'net/wireless/wext-compat.c')</div><table summary='diffstat' class='diffstat'>