[patch V4 21/65] x86/fpu: Get rid of using_compacted_format()

From: Thomas Gleixner
Date: Wed Jun 23 2021 - 08:24:36 EST


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: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
---
V2: New patch.
---
arch/x86/include/asm/fpu/xstate.h | 1 -
arch/x86/kernel/fpu/xstate.c | 22 ++++------------------
2 files changed, 4 insertions(+), 19 deletions(-)

--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -101,7 +101,6 @@ extern void __init update_regset_xstate_
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);
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -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(
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(
* 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