Commit ffd3e504 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Borislav Petkov

x86/fpu/xstate: Provide and use for_each_xfeature()

These loops evaluating xfeature bits are really hard to read. Create an
iterator and use for_each_set_bit_from() inside which already does the right
thing.

No functional changes.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.958107505@linutronix.de
parent 126fe040
......@@ -4,6 +4,7 @@
*
* Author: Suresh Siddha <suresh.b.siddha@intel.com>
*/
#include <linux/bitops.h>
#include <linux/compat.h>
#include <linux/cpu.h>
#include <linux/mman.h>
......@@ -20,6 +21,10 @@
#include "xstate.h"
#define for_each_extended_xfeature(bit, mask) \
(bit) = FIRST_EXTENDED_XFEATURE; \
for_each_set_bit_from(bit, (unsigned long *)&(mask), 8 * sizeof(mask))
/*
* Although we spell it out in here, the Processor Trace
* xfeature is completely unused. We use other mechanisms
......@@ -184,10 +189,7 @@ static void __init setup_xstate_features(void)
xstate_sizes[XFEATURE_SSE] = sizeof_field(struct fxregs_state,
xmm_space);
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
continue;
for_each_extended_xfeature(i, xfeatures_mask_all) {
cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
xstate_sizes[i] = eax;
......@@ -291,20 +293,15 @@ static void __init setup_xstate_comp_offsets(void)
xstate_comp_offsets[XFEATURE_SSE] = offsetof(struct fxregs_state,
xmm_space);
if (!boot_cpu_has(X86_FEATURE_XSAVES)) {
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (xfeature_enabled(i))
xstate_comp_offsets[i] = xstate_offsets[i];
}
if (!cpu_feature_enabled(X86_FEATURE_XSAVES)) {
for_each_extended_xfeature(i, xfeatures_mask_all)
xstate_comp_offsets[i] = xstate_offsets[i];
return;
}
next_offset = FXSAVE_SIZE + XSAVE_HDR_SIZE;
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
continue;
for_each_extended_xfeature(i, xfeatures_mask_all) {
if (xfeature_is_aligned(i))
next_offset = ALIGN(next_offset, 64);
......@@ -328,8 +325,8 @@ static void __init setup_supervisor_only_offsets(void)
next_offset = FXSAVE_SIZE + XSAVE_HDR_SIZE;
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i) || !xfeature_is_supervisor(i))
for_each_extended_xfeature(i, xfeatures_mask_all) {
if (!xfeature_is_supervisor(i))
continue;
if (xfeature_is_aligned(i))
......@@ -347,9 +344,7 @@ static void __init print_xstate_offset_size(void)
{
int i;
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
continue;
for_each_extended_xfeature(i, xfeatures_mask_all) {
pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n",
i, xstate_comp_offsets[i], i, xstate_sizes[i]);
}
......@@ -554,10 +549,7 @@ static void do_extra_xstate_size_checks(void)
int paranoid_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
int i;
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
continue;
for_each_extended_xfeature(i, xfeatures_mask_all) {
check_xstate_against_struct(i);
/*
* Supervisor state components can be managed only by
......@@ -586,7 +578,6 @@ static void do_extra_xstate_size_checks(void)
XSTATE_WARN_ON(paranoid_xstate_size != fpu_kernel_xstate_size);
}
/*
* Get total size of enabled xstates in XCR0 | IA32_XSS.
*
......@@ -969,6 +960,7 @@ void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk,
struct xregs_state *xinit = &init_fpstate.xsave;
struct xstate_header header;
unsigned int zerofrom;
u64 mask;
int i;
memset(&header, 0, sizeof(header));
......@@ -1022,17 +1014,15 @@ void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk,
zerofrom = offsetof(struct xregs_state, extended_state_area);
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
/*
* The ptrace buffer is in non-compacted XSAVE format.
* In non-compacted format disabled features still occupy
* state space, but there is no state to copy from in the
* compacted init_fpstate. The gap tracking will zero this
* later.
*/
if (!(xfeatures_mask_uabi() & BIT_ULL(i)))
continue;
/*
* The ptrace buffer is in non-compacted XSAVE format. In
* non-compacted format disabled features still occupy state space,
* but there is no state to copy from in the compacted
* init_fpstate. The gap tracking will zero these states.
*/
mask = xfeatures_mask_uabi();
for_each_extended_xfeature(i, mask) {
/*
* If there was a feature or alignment gap, zero the space
* in the destination buffer.
......
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