#include <asm/fpu/internal.h>
#include <asm/fpu/signal.h>
#include <asm/fpu/regset.h>
+#include <asm/fpu/xstate.h>
#include <asm/tlbflush.h>
static unsigned int xstate_sizes[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1};
static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask)*8];
+/*
+ * The XSAVE area of kernel can be in standard or compacted format;
+ * it is always in standard format for user mode. This is the user
+ * mode standard format size used for signal and ptrace frames.
+ */
+unsigned int fpu_user_xstate_size;
+
/*
* Clear all of the X86_FEATURE_* bits that are unavailable
* when the CPU has no XSAVE support.
}
EXPORT_SYMBOL_GPL(cpu_has_xfeatures);
+static int xfeature_is_supervisor(int xfeature_nr)
+{
+ /*
+ * We currently do not support supervisor states, but if
+ * we did, we could find out like this.
+ *
+ * SDM says: If state component 'i' is a user state component,
+ * ECX[0] return 0; if state component i is a supervisor
+ * state component, ECX[0] returns 1.
+ */
+ u32 eax, ebx, ecx, edx;
+
+ cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+ return !!(ecx & 1);
+}
+
+static int xfeature_is_user(int xfeature_nr)
+{
+ return !xfeature_is_supervisor(xfeature_nr);
+}
+
/*
* When executing XSAVEOPT (or other optimized XSAVE instructions), if
* a processor implementation detects that an FPU state component is still
*/
while (xfeatures) {
if (xfeatures & 0x1) {
- int offset = xstate_offsets[feature_bit];
+ int offset = xstate_comp_offsets[feature_bit];
int size = xstate_sizes[feature_bit];
memcpy((void *)fx + offset,
{
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.
+ */
+ WARN_ONCE((xfeatures_mask & XFEATURE_MASK_SUPERVISOR),
+ "x86/fpu: XSAVES supervisor states are not yet implemented.\n");
+
+ xfeatures_mask &= ~XFEATURE_MASK_SUPERVISOR;
cr4_set_bits(X86_CR4_OSXSAVE);
xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);
/* start at the beginnning of the "extended state" */
unsigned int last_good_offset = offsetof(struct xregs_state,
extended_state_area);
+ /*
+ * The FP xstates and SSE xstates are legacy states. They are always
+ * in the fixed offsets in the xsave area in either compacted form
+ * or standard form.
+ */
+ xstate_offsets[0] = 0;
+ xstate_sizes[0] = offsetof(struct fxregs_state, xmm_space);
+ xstate_offsets[1] = xstate_sizes[0];
+ xstate_sizes[1] = FIELD_SIZEOF(struct fxregs_state, xmm_space);
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
continue;
cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
- xstate_offsets[i] = ebx;
+
+ /*
+ * If an xfeature is supervisor state, the offset
+ * in EBX is invalid. We leave it to -1.
+ */
+ if (xfeature_is_user(i))
+ xstate_offsets[i] = ebx;
+
xstate_sizes[i] = eax;
/*
* In our xstate size checks, we assume that the
WARN_ONCE(last_good_offset > xstate_offsets[i],
"x86/fpu: misordered xstate at %d\n", last_good_offset);
last_good_offset = xstate_offsets[i];
-
- printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", i, ebx, i, eax);
}
}
print_xstate_feature(XFEATURE_MASK_PKRU);
}
+/*
+ * This check is important because it is easy to get XSTATE_*
+ * confused with XSTATE_BIT_*.
+ */
+#define CHECK_XFEATURE(nr) do { \
+ WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \
+ WARN_ON(nr >= XFEATURE_MAX); \
+} while (0)
+
+/*
+ * We could cache this like xstate_size[], but we only use
+ * it here, so it would be a waste of space.
+ */
+static int xfeature_is_aligned(int xfeature_nr)
+{
+ u32 eax, ebx, ecx, edx;
+
+ CHECK_XFEATURE(xfeature_nr);
+ cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+ /*
+ * The value returned by ECX[1] indicates the alignment
+ * of state component 'i' when the compacted format
+ * of the extended region of an XSAVE area is used:
+ */
+ return !!(ecx & 2);
+}
+
/*
* This function sets up offsets and sizes of all extended states in
* xsave area. This supports both standard format and compacted format
else
xstate_comp_sizes[i] = 0;
- if (i > FIRST_EXTENDED_XFEATURE)
+ if (i > FIRST_EXTENDED_XFEATURE) {
xstate_comp_offsets[i] = xstate_comp_offsets[i-1]
+ xstate_comp_sizes[i-1];
+ if (xfeature_is_aligned(i))
+ xstate_comp_offsets[i] =
+ ALIGN(xstate_comp_offsets[i], 64);
+ }
+ }
+}
+
+/*
+ * Print out xstate component offsets and sizes
+ */
+static void __init print_xstate_offset_size(void)
+{
+ int i;
+
+ for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
+ if (!xfeature_enabled(i))
+ continue;
+ pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n",
+ i, xstate_comp_offsets[i], i, xstate_sizes[i]);
}
}
setup_xstate_features();
print_xstate_features();
- if (boot_cpu_has(X86_FEATURE_XSAVES)) {
+ if (boot_cpu_has(X86_FEATURE_XSAVES))
init_fpstate.xsave.header.xcomp_bv = (u64)1 << 63 | xfeatures_mask;
- init_fpstate.xsave.header.xfeatures = xfeatures_mask;
- }
/*
- * Init all the features state with header_bv being 0x0
+ * Init all the features state with header.xfeatures being 0x0
*/
copy_kernel_to_xregs_booting(&init_fpstate.xsave);
copy_xregs_to_kernel_booting(&init_fpstate.xsave);
}
-static int xfeature_is_supervisor(int xfeature_nr)
-{
- /*
- * We currently do not support supervisor states, but if
- * we did, we could find out like this.
- *
- * SDM says: If state component i is a user state component,
- * ECX[0] return 0; if state component i is a supervisor
- * state component, ECX[0] returns 1.
- u32 eax, ebx, ecx, edx;
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx;
- return !!(ecx & 1);
- */
- return 0;
-}
-/*
-static int xfeature_is_user(int xfeature_nr)
-{
- return !xfeature_is_supervisor(xfeature_nr);
-}
-*/
-
-/*
- * This check is important because it is easy to get XSTATE_*
- * confused with XSTATE_BIT_*.
- */
-#define CHECK_XFEATURE(nr) do { \
- WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \
- WARN_ON(nr >= XFEATURE_MAX); \
-} while (0)
-
-/*
- * We could cache this like xstate_size[], but we only use
- * it here, so it would be a waste of space.
- */
-static int xfeature_is_aligned(int xfeature_nr)
+static int xfeature_uncompacted_offset(int xfeature_nr)
{
u32 eax, ebx, ecx, edx;
- CHECK_XFEATURE(xfeature_nr);
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
/*
- * The value returned by ECX[1] indicates the alignment
- * of state component i when the compacted format
- * of the extended region of an XSAVE area is used
+ * Only XSAVES supports supervisor states and it uses compacted
+ * format. Checking a supervisor state's uncompacted offset is
+ * an error.
*/
- return !!(ecx & 2);
-}
-
-static int xfeature_uncompacted_offset(int xfeature_nr)
-{
- u32 eax, ebx, ecx, edx;
+ if (XFEATURE_MASK_SUPERVISOR & (1 << xfeature_nr)) {
+ WARN_ONCE(1, "No fixed offset for xstate %d\n", xfeature_nr);
+ return -1;
+ }
CHECK_XFEATURE(xfeature_nr);
cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
* that it is obvious which aspect of 'XSAVES' is being handled
* by the calling code.
*/
-static int using_compacted_format(void)
+int using_compacted_format(void)
{
return boot_cpu_has(X86_FEATURE_XSAVES);
}
*/
paranoid_xstate_size += xfeature_size(i);
}
- XSTATE_WARN_ON(paranoid_xstate_size != xstate_size);
+ XSTATE_WARN_ON(paranoid_xstate_size != fpu_kernel_xstate_size);
}
+
/*
- * Calculate total size of enabled xstates in XCR0/xfeatures_mask.
+ * Get total size of enabled xstates in XCR0/xfeatures_mask.
*
* Note the SDM's wording here. "sub-function 0" only enumerates
* the size of the *user* states. If we use it to size a buffer
* Note that we do not currently set any bits on IA32_XSS so
* 'XCR0 | IA32_XSS == XCR0' for now.
*/
-static unsigned int __init calculate_xstate_size(void)
+static unsigned int __init get_xsaves_size(void)
{
unsigned int eax, ebx, ecx, edx;
- unsigned int calculated_xstate_size;
+ /*
+ * - CPUID function 0DH, sub-function 1:
+ * EBX enumerates the size (in bytes) required by
+ * the XSAVES instruction for an XSAVE area
+ * containing all the state components
+ * corresponding to bits currently set in
+ * XCR0 | IA32_XSS.
+ */
+ cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx);
+ return ebx;
+}
- if (!boot_cpu_has(X86_FEATURE_XSAVES)) {
- /*
- * - CPUID function 0DH, sub-function 0:
- * EBX enumerates the size (in bytes) required by
- * the XSAVE instruction for an XSAVE area
- * containing all the *user* state components
- * corresponding to bits currently set in XCR0.
- */
- cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
- calculated_xstate_size = ebx;
- } else {
- /*
- * - CPUID function 0DH, sub-function 1:
- * EBX enumerates the size (in bytes) required by
- * the XSAVES instruction for an XSAVE area
- * containing all the state components
- * corresponding to bits currently set in
- * XCR0 | IA32_XSS.
- */
- cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx);
- calculated_xstate_size = ebx;
- }
- return calculated_xstate_size;
+static unsigned int __init get_xsave_size(void)
+{
+ unsigned int eax, ebx, ecx, edx;
+ /*
+ * - CPUID function 0DH, sub-function 0:
+ * EBX enumerates the size (in bytes) required by
+ * the XSAVE instruction for an XSAVE area
+ * containing all the *user* state components
+ * corresponding to bits currently set in XCR0.
+ */
+ cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
+ return ebx;
}
/*
static int init_xstate_size(void)
{
/* Recompute the context size for enabled features: */
- unsigned int possible_xstate_size = calculate_xstate_size();
+ unsigned int possible_xstate_size;
+ unsigned int xsave_size;
+
+ xsave_size = get_xsave_size();
+
+ if (boot_cpu_has(X86_FEATURE_XSAVES))
+ possible_xstate_size = get_xsaves_size();
+ else
+ possible_xstate_size = xsave_size;
/* Ensure we have the space to store all enabled: */
if (!is_supported_xstate_size(possible_xstate_size))
* The size is OK, we are definitely going to use xsave,
* make it known to the world that we need more space.
*/
- xstate_size = possible_xstate_size;
+ fpu_kernel_xstate_size = possible_xstate_size;
do_extra_xstate_size_checks();
+
+ /*
+ * User space is always in standard format.
+ */
+ fpu_user_xstate_size = xsave_size;
return 0;
}
xfeatures_mask = eax + ((u64)edx << 32);
if ((xfeatures_mask & XFEATURE_MASK_FPSSE) != XFEATURE_MASK_FPSSE) {
+ /*
+ * This indicates that something really unexpected happened
+ * with the enumeration. Disable XSAVE and try to continue
+ * booting without it. This is too early to BUG().
+ */
pr_err("x86/fpu: FP/SSE not present amongst the CPU's xstate features: 0x%llx.\n", xfeatures_mask);
- BUG();
+ goto out_disable;
}
xfeatures_mask &= fpu__get_supported_xfeatures_mask();
/* Enable xstate instructions to be able to continue with initialization: */
fpu__init_cpu_xstate();
err = init_xstate_size();
- if (err) {
- /* something went wrong, boot without any XSAVE support */
- fpu__init_disable_system_xstate();
- return;
- }
+ if (err)
+ goto out_disable;
+
+ /*
+ * 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(xstate_size, xfeatures_mask);
fpu__init_prepare_fx_sw_frame();
setup_init_fpu_buf();
setup_xstate_comp();
+ print_xstate_offset_size();
pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is %d bytes, using '%s' format.\n",
xfeatures_mask,
- xstate_size,
+ fpu_kernel_xstate_size,
boot_cpu_has(X86_FEATURE_XSAVES) ? "compacted" : "standard");
+ return;
+
+out_disable:
+ /* something went wrong, try to boot without any XSAVE support */
+ fpu__init_disable_system_xstate();
}
/*
{
int feature_nr = fls64(xstate_feature_mask) - 1;
+ if (!xfeature_enabled(feature_nr)) {
+ WARN_ON_FPU(1);
+ return NULL;
+ }
+
return (void *)xsave + xstate_comp_offsets[feature_nr];
}
/*
if (!boot_cpu_has(X86_FEATURE_OSPKE))
return -EINVAL;
- /* Set the bits we need in PKRU */
+ /* Set the bits we need in PKRU: */
if (init_val & PKEY_DISABLE_ACCESS)
new_pkru_bits |= PKRU_AD_BIT;
if (init_val & PKEY_DISABLE_WRITE)
new_pkru_bits |= PKRU_WD_BIT;
- /* Shift the bits in to the correct place in PKRU for pkey. */
+ /* Shift the bits in to the correct place in PKRU for pkey: */
new_pkru_bits <<= pkey_shift;
- /* Locate old copy of the state in the xsave buffer */
+ /* Locate old copy of the state in the xsave buffer: */
old_pkru_state = get_xsave_addr(xsave, XFEATURE_MASK_PKRU);
/*
else
new_pkru_state.pkru = old_pkru_state->pkru;
- /* mask off any old bits in place */
+ /* Mask off any old bits in place: */
new_pkru_state.pkru &= ~((PKRU_AD_BIT|PKRU_WD_BIT) << pkey_shift);
- /* Set the newly-requested bits */
+
+ /* Set the newly-requested bits: */
new_pkru_state.pkru |= new_pkru_bits;
/*
*/
new_pkru_state.pad = 0;
- fpu__xfeature_set_state(XFEATURE_MASK_PKRU, &new_pkru_state,
- sizeof(new_pkru_state));
+ fpu__xfeature_set_state(XFEATURE_MASK_PKRU, &new_pkru_state, sizeof(new_pkru_state));
+
+ return 0;
+}
+
+/*
+ * This is similar to user_regset_copyout(), but will not add offset to
+ * the source data pointer or increment pos, count, kbuf, and ubuf.
+ */
+static inline int xstate_copyout(unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf,
+ const void *data, const int start_pos,
+ const int end_pos)
+{
+ if ((count == 0) || (pos < start_pos))
+ return 0;
+
+ if (end_pos < 0 || pos < end_pos) {
+ unsigned int copy = (end_pos < 0 ? count : min(count, end_pos - pos));
+
+ if (kbuf) {
+ memcpy(kbuf + pos, data, copy);
+ } else {
+ if (__copy_to_user(ubuf + pos, data, copy))
+ return -EFAULT;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Convert from kernel XSAVES compacted format to standard format and copy
+ * to a ptrace buffer. It supports partial copy but pos always starts from
+ * zero. This is called from xstateregs_get() and there we check the CPU
+ * has XSAVES.
+ */
+int copyout_from_xsaves(unsigned int pos, unsigned int count, void *kbuf,
+ void __user *ubuf, struct xregs_state *xsave)
+{
+ unsigned int offset, size;
+ int ret, i;
+ struct xstate_header header;
+
+ /*
+ * Currently copy_regset_to_user() starts from pos 0:
+ */
+ if (unlikely(pos != 0))
+ return -EFAULT;
+
+ /*
+ * The destination is a ptrace buffer; we put in only user xstates:
+ */
+ memset(&header, 0, sizeof(header));
+ header.xfeatures = xsave->header.xfeatures;
+ header.xfeatures &= ~XFEATURE_MASK_SUPERVISOR;
+
+ /*
+ * Copy xregs_state->header:
+ */
+ offset = offsetof(struct xregs_state, header);
+ size = sizeof(header);
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, &header, 0, count);
+
+ if (ret)
+ return ret;
+
+ for (i = 0; i < XFEATURE_MAX; i++) {
+ /*
+ * Copy only in-use xstates:
+ */
+ if ((header.xfeatures >> i) & 1) {
+ void *src = __raw_xsave_addr(xsave, 1 << i);
+
+ offset = xstate_offsets[i];
+ size = xstate_sizes[i];
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, src, 0, count);
+
+ if (ret)
+ return ret;
+
+ if (offset + size >= count)
+ break;
+ }
+
+ }
+
+ /*
+ * Fill xsave->i387.sw_reserved value for ptrace frame:
+ */
+ offset = offsetof(struct fxregs_state, sw_reserved);
+ size = sizeof(xstate_fx_sw_bytes);
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, xstate_fx_sw_bytes, 0, count);
+
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+/*
+ * Convert from a ptrace standard-format buffer to kernel XSAVES format
+ * and copy to the target thread. This is called from xstateregs_set() and
+ * there we check the CPU has XSAVES and a whole standard-sized buffer
+ * exists.
+ */
+int copyin_to_xsaves(const void *kbuf, const void __user *ubuf,
+ struct xregs_state *xsave)
+{
+ unsigned int offset, size;
+ int i;
+ u64 xfeatures;
+ u64 allowed_features;
+
+ offset = offsetof(struct xregs_state, header);
+ size = sizeof(xfeatures);
+
+ if (kbuf) {
+ memcpy(&xfeatures, kbuf + offset, size);
+ } else {
+ if (__copy_from_user(&xfeatures, ubuf + offset, size))
+ return -EFAULT;
+ }
+
+ /*
+ * Reject if the user sets any disabled or supervisor features:
+ */
+ allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR;
+
+ if (xfeatures & ~allowed_features)
+ return -EINVAL;
+
+ for (i = 0; i < XFEATURE_MAX; i++) {
+ u64 mask = ((u64)1 << i);
+
+ if (xfeatures & mask) {
+ void *dst = __raw_xsave_addr(xsave, 1 << i);
+
+ offset = xstate_offsets[i];
+ size = xstate_sizes[i];
+
+ if (kbuf) {
+ memcpy(dst, kbuf + offset, size);
+ } else {
+ if (__copy_from_user(dst, ubuf + offset, size))
+ return -EFAULT;
+ }
+ }
+ }
+
+ /*
+ * 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;
+
+ /*
+ * Add back in the features that came in from userspace:
+ */
+ xsave->header.xfeatures |= xfeatures;
return 0;
}
projects / linux-2.6-block.git / commitdiff