return boot_cpu_has(X86_FEATURE_XSAVES);
}
+/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */
+int validate_xstate_header(const struct xstate_header *hdr)
+{
+ /* No unknown or supervisor features may be set */
+ if (hdr->xfeatures & (~xfeatures_mask | XFEATURE_MASK_SUPERVISOR))
+ return -EINVAL;
+
+ /* Userspace must use the uncompacted format */
+ if (hdr->xcomp_bv)
+ return -EINVAL;
+
+ /*
+ * If 'reserved' is shrunken to add a new field, make sure to validate
+ * that new field here!
+ */
+ BUILD_BUG_ON(sizeof(hdr->reserved) != 48);
+
+ /* No reserved bits may be set */
+ if (memchr_inv(hdr->reserved, 0, sizeof(hdr->reserved)))
+ return -EINVAL;
+
+ return 0;
+}
+
static void __xstate_dump_leaves(void)
{
int i;
{
struct fpu *fpu = ¤t->thread.fpu;
- if (!fpu->fpstate_active)
+ if (!fpu->initialized)
return NULL;
/*
* fpu__save() takes the CPU's xstate registers
}
#endif /* ! CONFIG_ARCH_HAS_PKEYS */
+/*
+ * Weird legacy quirk: SSE and YMM states store information in the
+ * MXCSR and MXCSR_FLAGS fields of the FP area. That means if the FP
+ * area is marked as unused in the xfeatures header, we need to copy
+ * MXCSR and MXCSR_FLAGS if either SSE or YMM are in use.
+ */
+static inline bool xfeatures_mxcsr_quirk(u64 xfeatures)
+{
+ if (!(xfeatures & (XFEATURE_MASK_SSE|XFEATURE_MASK_YMM)))
+ return false;
+
+ if (xfeatures & XFEATURE_MASK_FP)
+ return false;
+
+ return true;
+}
+
/*
* 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)
+static inline void
+__copy_xstate_to_kernel(void *kbuf, const void *data,
+ unsigned int offset, unsigned int size, unsigned int size_total)
{
- if ((count == 0) || (pos < start_pos))
- return 0;
+ if (offset < size_total) {
+ unsigned int copy = min(size, size_total - offset);
- if (end_pos < 0 || pos < end_pos) {
- unsigned int copy = (end_pos < 0 ? count : min(count, end_pos - pos));
+ memcpy(kbuf + offset, data, copy);
+ }
+}
- if (kbuf) {
- memcpy(kbuf + pos, data, copy);
- } else {
- if (__copy_to_user(ubuf + pos, data, copy))
- return -EFAULT;
+/*
+ * Convert from kernel XSAVES compacted format to standard format and copy
+ * to a kernel-space 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 copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total)
+{
+ unsigned int offset, size;
+ struct xstate_header header;
+ int i;
+
+ /*
+ * Currently copy_regset_to_user() starts from pos 0:
+ */
+ if (unlikely(offset_start != 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);
+
+ __copy_xstate_to_kernel(kbuf, &header, offset, size, size_total);
+
+ 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];
+
+ /* The next component has to fit fully into the output buffer: */
+ if (offset + size > size_total)
+ break;
+
+ __copy_xstate_to_kernel(kbuf, src, offset, size, size_total);
}
+
+ }
+
+ if (xfeatures_mxcsr_quirk(header.xfeatures)) {
+ offset = offsetof(struct fxregs_state, mxcsr);
+ size = MXCSR_AND_FLAGS_SIZE;
+ __copy_xstate_to_kernel(kbuf, &xsave->i387.mxcsr, offset, size, size_total);
+ }
+
+ /*
+ * Fill xsave->i387.sw_reserved value for ptrace frame:
+ */
+ offset = offsetof(struct fxregs_state, sw_reserved);
+ size = sizeof(xstate_fx_sw_bytes);
+
+ __copy_xstate_to_kernel(kbuf, xstate_fx_sw_bytes, offset, size, size_total);
+
+ return 0;
+}
+
+static inline int
+__copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int offset, unsigned int size, unsigned int size_total)
+{
+ if (!size)
+ return 0;
+
+ if (offset < size_total) {
+ unsigned int copy = min(size, size_total - offset);
+
+ if (__copy_to_user(ubuf + offset, 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
+ * to a user-space 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)
+int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total)
{
unsigned int offset, size;
int ret, i;
/*
* Currently copy_regset_to_user() starts from pos 0:
*/
- if (unlikely(pos != 0))
+ if (unlikely(offset_start != 0))
return -EFAULT;
/*
offset = offsetof(struct xregs_state, header);
size = sizeof(header);
- ret = xstate_copyout(offset, size, kbuf, ubuf, &header, 0, count);
-
+ ret = __copy_xstate_to_user(ubuf, &header, offset, size, size_total);
if (ret)
return ret;
offset = xstate_offsets[i];
size = xstate_sizes[i];
- ret = xstate_copyout(offset, size, kbuf, ubuf, src, 0, count);
+ /* The next component has to fit fully into the output buffer: */
+ if (offset + size > size_total)
+ break;
+ ret = __copy_xstate_to_user(ubuf, src, offset, size, size_total);
if (ret)
return ret;
-
- if (offset + size >= count)
- break;
}
}
+ if (xfeatures_mxcsr_quirk(header.xfeatures)) {
+ offset = offsetof(struct fxregs_state, mxcsr);
+ size = MXCSR_AND_FLAGS_SIZE;
+ __copy_xstate_to_user(ubuf, &xsave->i387.mxcsr, offset, size, size_total);
+ }
+
/*
* 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);
-
+ ret = __copy_xstate_to_user(ubuf, xstate_fx_sw_bytes, offset, size, size_total);
if (ret)
return ret;
}
/*
- * 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.
+ * Convert from a ptrace standard-format kernel buffer to kernel XSAVES format
+ * and copy to the target thread. This is called from xstateregs_set().
*/
-int copyin_to_xsaves(const void *kbuf, const void __user *ubuf,
- struct xregs_state *xsave)
+int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf)
{
unsigned int offset, size;
int i;
- u64 xfeatures;
- u64 allowed_features;
+ struct xstate_header hdr;
offset = offsetof(struct xregs_state, header);
- size = sizeof(xfeatures);
+ size = sizeof(hdr);
- if (kbuf) {
- memcpy(&xfeatures, kbuf + offset, size);
- } else {
- if (__copy_from_user(&xfeatures, ubuf + offset, size))
- return -EFAULT;
+ memcpy(&hdr, kbuf + offset, size);
+
+ if (validate_xstate_header(&hdr))
+ return -EINVAL;
+
+ for (i = 0; i < XFEATURE_MAX; i++) {
+ u64 mask = ((u64)1 << i);
+
+ if (hdr.xfeatures & mask) {
+ void *dst = __raw_xsave_addr(xsave, 1 << i);
+
+ offset = xstate_offsets[i];
+ size = xstate_sizes[i];
+
+ memcpy(dst, kbuf + offset, size);
+ }
+ }
+
+ if (xfeatures_mxcsr_quirk(hdr.xfeatures)) {
+ offset = offsetof(struct fxregs_state, mxcsr);
+ size = MXCSR_AND_FLAGS_SIZE;
+ memcpy(&xsave->i387.mxcsr, kbuf + offset, size);
}
/*
- * Reject if the user sets any disabled or supervisor features:
+ * 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:
*/
- allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR;
+ xsave->header.xfeatures |= hdr.xfeatures;
- if (xfeatures & ~allowed_features)
+ return 0;
+}
+
+/*
+ * Convert from a ptrace or sigreturn standard-format user-space buffer to
+ * kernel XSAVES format and copy to the target thread. This is called from
+ * xstateregs_set(), as well as potentially from the sigreturn() and
+ * rt_sigreturn() system calls.
+ */
+int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf)
+{
+ unsigned int offset, size;
+ int i;
+ struct xstate_header hdr;
+
+ offset = offsetof(struct xregs_state, header);
+ size = sizeof(hdr);
+
+ if (__copy_from_user(&hdr, ubuf + offset, size))
+ return -EFAULT;
+
+ if (validate_xstate_header(&hdr))
return -EINVAL;
for (i = 0; i < XFEATURE_MAX; i++) {
u64 mask = ((u64)1 << i);
- if (xfeatures & mask) {
+ if (hdr.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;
- }
+ if (__copy_from_user(dst, ubuf + offset, size))
+ return -EFAULT;
}
}
+ if (xfeatures_mxcsr_quirk(hdr.xfeatures)) {
+ offset = offsetof(struct fxregs_state, mxcsr);
+ size = MXCSR_AND_FLAGS_SIZE;
+ if (__copy_from_user(&xsave->i387.mxcsr, ubuf + offset, size))
+ return -EFAULT;
+ }
+
/*
* The state that came in from userspace was user-state only.
* Mask all the user states out of 'xfeatures':
/*
* Add back in the features that came in from userspace:
*/
- xsave->header.xfeatures |= xfeatures;
+ xsave->header.xfeatures |= hdr.xfeatures;
return 0;
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff