Commit 02b93c0b authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Borislav Petkov
Browse files

x86/fpu: Get rid of using_compacted_format() 



This function is pointlessly global and a complete misnomer because it's
usage is related to both supervisor state checks and compacted format
checks. Remove it and just make the conditions check the XSAVES feature.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210623121453.425493349@linutronix.de
parent dbb60ac7

arch/x86/include/asm/fpu/xstate.h

+0 −1
Original line number Diff line number Diff line
@@ -101,7 +101,6 @@ extern void __init update_regset_xstate_info(unsigned int size, 
					     u64 xstate_mask);



void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr);

int using_compacted_format(void);

int xfeature_size(int xfeature_nr);

int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf);

int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf);

arch/x86/kernel/fpu/xstate.c

+4 −18
Original line number Diff line number Diff line
@@ -449,20 +449,6 @@ int xfeature_size(int xfeature_nr) 
	return eax;

}



/*

 * 'XSAVES' implies two different things:

 * 1. saving of supervisor/system state

 * 2. using the compacted format

 *

 * Use this function when dealing with the compacted format so

 * that it is obvious which aspect of 'XSAVES' is being handled

 * by the calling code.

 */

int using_compacted_format(void)

{

	return boot_cpu_has(X86_FEATURE_XSAVES);

}



/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */

static int validate_user_xstate_header(const struct xstate_header *hdr)

{
@@ -581,9 +567,9 @@ static void do_extra_xstate_size_checks(void) 
		check_xstate_against_struct(i);

		/*

		 * Supervisor state components can be managed only by

		 * XSAVES, which is compacted-format only.

		 * XSAVES.

		 */

		if (!using_compacted_format())

		if (!cpu_feature_enabled(X86_FEATURE_XSAVES))

			XSTATE_WARN_ON(xfeature_is_supervisor(i));



		/* Align from the end of the previous feature */
@@ -593,9 +579,9 @@ static void do_extra_xstate_size_checks(void) 
		 * The offset of a given state in the non-compacted

		 * format is given to us in a CPUID leaf.  We check

		 * them for being ordered (increasing offsets) in

		 * setup_xstate_features().

		 * setup_xstate_features(). XSAVES uses compacted format.

		 */

		if (!using_compacted_format())

		if (!cpu_feature_enabled(X86_FEATURE_XSAVES))

			paranoid_xstate_size = xfeature_uncompacted_offset(i);

		/*

		 * The compacted-format offset always depends on where