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x86/fpu/xstate: Define new macros for supervisor and user xstates

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XCNTXT_MASK is 'all supported xfeatures' before introducing supervisor
xstates.  Rename it to XFEATURE_MASK_USER_SUPPORTED to make clear that
these are user xstates.

Replace XFEATURE_MASK_SUPERVISOR with the following:
- XFEATURE_MASK_SUPERVISOR_SUPPORTED: Currently nothing.  ENQCMD and
  Control-flow Enforcement Technology (CET) will be introduced in separate
  series.
- XFEATURE_MASK_SUPERVISOR_UNSUPPORTED: Currently only Processor Trace.
- XFEATURE_MASK_SUPERVISOR_ALL: the combination of above.

Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200512145444.15483-3-yu-cheng.yu@intel.com
This commit is contained in:
Fenghua Yu
2020-05-12 07:54:36 -07:00
committed by Borislav Petkov
parent 5274e6c172
commit 8ab22804ef
3 changed files with 37 additions and 26 deletions
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26
arch/x86/kernel/fpu/xstate.c
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@@ -208,14 +208,13 @@ void fpu__init_cpu_xstate(void)
if (!boot_cpu_has(X86_FEATURE_XSAVE) || !xfeatures_mask)
return;
/*
* Make it clear that XSAVES supervisor states are not yet
* implemented should anyone expect it to work by changing
* bits in XFEATURE_MASK_* macros and XCR0.
* Unsupported supervisor xstates should not be found in
* the xfeatures mask.
*/
WARN_ONCE((xfeatures_mask & XFEATURE_MASK_SUPERVISOR),
"x86/fpu: XSAVES supervisor states are not yet implemented.\n");
WARN_ONCE((xfeatures_mask & XFEATURE_MASK_SUPERVISOR_UNSUPPORTED),
"x86/fpu: Found unsupported supervisor xstates.\n");
xfeatures_mask &= ~XFEATURE_MASK_SUPERVISOR;
xfeatures_mask &= ~XFEATURE_MASK_SUPERVISOR_UNSUPPORTED;
cr4_set_bits(X86_CR4_OSXSAVE);
xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);
@@ -438,7 +437,7 @@ static int xfeature_uncompacted_offset(int xfeature_nr)
* format. Checking a supervisor state's uncompacted offset is
* an error.
*/
if (XFEATURE_MASK_SUPERVISOR & BIT_ULL(xfeature_nr)) {
if (XFEATURE_MASK_SUPERVISOR_ALL & BIT_ULL(xfeature_nr)) {
WARN_ONCE(1, "No fixed offset for xstate %d\n", xfeature_nr);
return -1;
}
@@ -475,7 +474,7 @@ int using_compacted_format(void)
int validate_user_xstate_header(const struct xstate_header *hdr)
{
/* No unknown or supervisor features may be set */
if (hdr->xfeatures & (~xfeatures_mask | XFEATURE_MASK_SUPERVISOR))
if (hdr->xfeatures & ~(xfeatures_mask & XFEATURE_MASK_USER_SUPPORTED))
return -EINVAL;
/* Userspace must use the uncompacted format */
@@ -768,7 +767,8 @@ void __init fpu__init_system_xstate(void)
* Update info used for ptrace frames; use standard-format size and no
* supervisor xstates:
*/
update_regset_xstate_info(fpu_user_xstate_size, xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR);
update_regset_xstate_info(fpu_user_xstate_size,
xfeatures_mask & XFEATURE_MASK_USER_SUPPORTED);
fpu__init_prepare_fx_sw_frame();
setup_init_fpu_buf();
@@ -996,7 +996,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of
*/
memset(&header, 0, sizeof(header));
header.xfeatures = xsave->header.xfeatures;
header.xfeatures &= ~XFEATURE_MASK_SUPERVISOR;
header.xfeatures &= XFEATURE_MASK_USER_SUPPORTED;
/*
* Copy xregs_state->header:
@@ -1080,7 +1080,7 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i
*/
memset(&header, 0, sizeof(header));
header.xfeatures = xsave->header.xfeatures;
header.xfeatures &= ~XFEATURE_MASK_SUPERVISOR;
header.xfeatures &= XFEATURE_MASK_USER_SUPPORTED;
/*
* Copy xregs_state->header:
@@ -1173,7 +1173,7 @@ int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf)
* The state that came in from userspace was user-state only.
* Mask all the user states out of 'xfeatures':
*/
xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR;
xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR_ALL;
/*
* Add back in the features that came in from userspace:
@@ -1229,7 +1229,7 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf)
* The state that came in from userspace was user-state only.
* Mask all the user states out of 'xfeatures':
*/
xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR;
xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR_ALL;
/*
* Add back in the features that came in from userspace: