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

Commit d744dcad authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
Browse files

selftests/x86/ldt_gdt: Add infrastructure to test set_thread_area() 



Much of the test design could apply to set_thread_area() (i.e. GDT),
not just modify_ldt().  Add set_thread_area() to the
install_valid_mode() helper.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/02c23f8fba5547007f741dc24c3926e5284ede02.1509794321.git.luto@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent d60ad744

tools/testing/selftests/x86/ldt_gdt.c

+37 −16
Original line number Diff line number Diff line
@@ -137,30 +137,51 @@ static void check_valid_segment(uint16_t index, int ldt, 
	}

}



static bool install_valid_mode(const struct user_desc *desc, uint32_t ar,

			       bool oldmode)

static bool install_valid_mode(const struct user_desc *d, uint32_t ar,

			       bool oldmode, bool ldt)

{

	int ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11,

			  desc, sizeof(*desc));

	struct user_desc desc = *d;

	int ret;



	if (!ldt) {

#ifndef __i386__

		/* No point testing set_thread_area in a 64-bit build */

		return false;

#endif

		if (!gdt_entry_num)

			return false;

		desc.entry_number = gdt_entry_num;



		ret = syscall(SYS_set_thread_area, &desc);

	} else {

		ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11,

			      &desc, sizeof(desc));



		if (ret < -1)

			errno = -ret;



		if (ret != 0 && errno == ENOSYS) {

			printf("[OK]\tmodify_ldt returned -ENOSYS\n");

			return false;

		}

	}



	if (ret == 0) {

		uint32_t limit = desc->limit;

		if (desc->limit_in_pages)

		uint32_t limit = desc.limit;

		if (desc.limit_in_pages)

			limit = (limit << 12) + 4095;

		check_valid_segment(desc->entry_number, 1, ar, limit, true);

		check_valid_segment(desc.entry_number, ldt, ar, limit, true);

		return true;

	} else if (errno == ENOSYS) {

		printf("[OK]\tmodify_ldt returned -ENOSYS\n");

		return false;

	} else {

		if (desc->seg_32bit) {

			printf("[FAIL]\tUnexpected modify_ldt failure %d\n",

		if (desc.seg_32bit) {

			printf("[FAIL]\tUnexpected %s failure %d\n",

			       ldt ? "modify_ldt" : "set_thread_area",

			       errno);

			nerrs++;

			return false;

		} else {

			printf("[OK]\tmodify_ldt rejected 16 bit segment\n");

			printf("[OK]\t%s rejected 16 bit segment\n",

			       ldt ? "modify_ldt" : "set_thread_area");

			return false;

		}

	}
@@ -168,7 +189,7 @@ static bool install_valid_mode(const struct user_desc *desc, uint32_t ar, 


static bool install_valid(const struct user_desc *desc, uint32_t ar)

{

	return install_valid_mode(desc, ar, false);

	return install_valid_mode(desc, ar, false, true);

}



static void install_invalid(const struct user_desc *desc, bool oldmode)