if (use_xsave()) {
/*
- * Note: we don't need to zero the reserved bits in the
- * xstate_header here because we either didn't copy them at all,
- * or we checked earlier that they aren't set.
+ * Clear all feature bits which are not set in
+ * user_xfeatures and clear all extended features
+ * for fx_only mode.
*/
+ u64 mask = fx_only ? XFEATURE_MASK_FPSSE : user_xfeatures;
/*
- * 'user_xfeatures' might have bits clear which are
- * set in header->xfeatures. This represents features that
- * were in init state prior to a signal delivery, and need
- * to be reset back to the init state. Clear any user
- * feature bits which are set in the kernel buffer to get
- * them back to the init state.
- *
- * Supervisor state is unchanged by input from userspace.
- * Ensure supervisor state bits stay set and supervisor
- * state is not modified.
+ * Supervisor state has to be preserved. The sigframe
+ * restore can only modify user features, i.e. @mask
+ * cannot contain them.
*/
- if (fx_only)
- header->xfeatures = XFEATURE_MASK_FPSSE;
- else
- header->xfeatures &= user_xfeatures |
- xfeatures_mask_supervisor();
+ header->xfeatures &= mask | xfeatures_mask_supervisor();
}
if (use_fxsr()) {
return 0;
}
- if (!access_ok(buf, size))
- return -EACCES;
+ if (!access_ok(buf, size)) {
+ ret = -EACCES;
+ goto out;
+ }
- if (!static_cpu_has(X86_FEATURE_FPU))
- return fpregs_soft_set(current, NULL,
- 0, sizeof(struct user_i387_ia32_struct),
- NULL, buf) != 0;
+ if (!static_cpu_has(X86_FEATURE_FPU)) {
+ ret = fpregs_soft_set(current, NULL, 0,
+ sizeof(struct user_i387_ia32_struct),
+ NULL, buf);
+ goto out;
+ }
if (use_xsave()) {
struct _fpx_sw_bytes fx_sw_user;
fpregs_unlock();
return 0;
}
+
+ /*
+ * The above did an FPU restore operation, restricted to
+ * the user portion of the registers, and failed, but the
+ * microcode might have modified the FPU registers
+ * nevertheless.
+ *
+ * If the FPU registers do not belong to current, then
+ * invalidate the FPU register state otherwise the task might
+ * preempt current and return to user space with corrupted
+ * FPU registers.
+ *
+ * In case current owns the FPU registers then no further
+ * action is required. The fixup below will handle it
+ * correctly.
+ */
+ if (test_thread_flag(TIF_NEED_FPU_LOAD))
+ __cpu_invalidate_fpregs_state();
+
fpregs_unlock();
} else {
/*
*/
ret = __copy_from_user(&env, buf, sizeof(env));
if (ret)
- goto err_out;
+ goto out;
envp = &env;
}
if (use_xsave() && !fx_only) {
u64 init_bv = xfeatures_mask_user() & ~user_xfeatures;
- if (using_compacted_format()) {
- ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
- } else {
- ret = __copy_from_user(&fpu->state.xsave, buf_fx, state_size);
-
- if (!ret && state_size > offsetof(struct xregs_state, header))
- ret = validate_user_xstate_header(&fpu->state.xsave.header);
- }
+ ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
if (ret)
- goto err_out;
+ goto out;
sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
fx_only);
ret = __copy_from_user(&fpu->state.fxsave, buf_fx, state_size);
if (ret) {
ret = -EFAULT;
- goto err_out;
+ goto out;
}
sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
} else {
ret = __copy_from_user(&fpu->state.fsave, buf_fx, state_size);
if (ret)
- goto err_out;
+ goto out;
fpregs_lock();
ret = copy_kernel_to_fregs_err(&fpu->state.fsave);
fpregs_deactivate(fpu);
fpregs_unlock();
- err_out:
+ out:
if (ret)
fpu__clear_user_states(fpu);
return ret;
return sp;
}
+
+unsigned long fpu__get_fpstate_size(void)
+{
+ unsigned long ret = xstate_sigframe_size();
+
+ /*
+ * This space is needed on (most) 32-bit kernels, or when a 32-bit
+ * app is running on a 64-bit kernel. To keep things simple, just
+ * assume the worst case and always include space for 'freg_state',
+ * even for 64-bit apps on 64-bit kernels. This wastes a bit of
+ * space, but keeps the code simple.
+ */
+ if ((IS_ENABLED(CONFIG_IA32_EMULATION) ||
+ IS_ENABLED(CONFIG_X86_32)) && use_fxsr())
+ ret += sizeof(struct fregs_state);
+
+ return ret;
+}
+
/*
* Prepare the SW reserved portion of the fxsave memory layout, indicating
* the presence of the extended state information in the memory layout
}
}
+ /*
+ * All supported features have either init state all zeros or are
+ * handled in setup_init_fpu() individually. This is an explicit
+ * feature list and does not use XFEATURE_MASK*SUPPORTED to catch
+ * newly added supported features at build time and make people
+ * actually look at the init state for the new feature.
+ */
+ #define XFEATURES_INIT_FPSTATE_HANDLED \
+ (XFEATURE_MASK_FP | \
+ XFEATURE_MASK_SSE | \
+ XFEATURE_MASK_YMM | \
+ XFEATURE_MASK_OPMASK | \
+ XFEATURE_MASK_ZMM_Hi256 | \
+ XFEATURE_MASK_Hi16_ZMM | \
+ XFEATURE_MASK_PKRU | \
+ XFEATURE_MASK_BNDREGS | \
+ XFEATURE_MASK_BNDCSR | \
+ XFEATURE_MASK_PASID)
+
/*
* setup the xstate image representing the init state
*/
{
static int on_boot_cpu __initdata = 1;
+ BUILD_BUG_ON((XFEATURE_MASK_USER_SUPPORTED |
+ XFEATURE_MASK_SUPERVISOR_SUPPORTED) !=
+ XFEATURES_INIT_FPSTATE_HANDLED);
+
WARN_ON_FPU(!on_boot_cpu);
on_boot_cpu = 0;
copy_kernel_to_xregs_booting(&init_fpstate.xsave);
/*
- * Dump the init state again. This is to identify the init state
- * of any feature which is not represented by all zero's.
+ * All components are now in init state. Read the state back so
+ * that init_fpstate contains all non-zero init state. This only
+ * works with XSAVE, but not with XSAVEOPT and XSAVES because
+ * those use the init optimization which skips writing data for
+ * components in init state.
+ *
+ * XSAVE could be used, but that would require to reshuffle the
+ * data when XSAVES is available because XSAVES uses xstate
+ * compaction. But doing so is a pointless exercise because most
+ * components have an all zeros init state except for the legacy
+ * ones (FP and SSE). Those can be saved with FXSAVE into the
+ * legacy area. Adding new features requires to ensure that init
+ * state is all zeroes or if not to add the necessary handling
+ * here.
*/
- copy_xregs_to_kernel_booting(&init_fpstate.xsave);
+ fxsave(&init_fpstate.fxsave);
}
static int xfeature_uncompacted_offset(int xfeature_nr)
offset = offsetof(struct xregs_state, header);
size = sizeof(hdr);
- if (__copy_from_user(&hdr, ubuf + offset, size))
+ if (copy_from_user(&hdr, ubuf + offset, size))
return -EFAULT;
if (validate_user_xstate_header(&hdr))
offset = xstate_offsets[i];
size = xstate_sizes[i];
- if (__copy_from_user(dst, ubuf + offset, size))
+ 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))
+ if (copy_from_user(&xsave->i387.mxcsr, ubuf + offset, size))
return -EFAULT;
}
return 0;
}
#endif /* CONFIG_PROC_PID_ARCH_STATUS */
-
- #ifdef CONFIG_IOMMU_SUPPORT
- void update_pasid(void)
- {
- u64 pasid_state;
- u32 pasid;
-
- if (!cpu_feature_enabled(X86_FEATURE_ENQCMD))
- return;
-
- if (!current->mm)
- return;
-
- pasid = READ_ONCE(current->mm->pasid);
- /* Set the valid bit in the PASID MSR/state only for valid pasid. */
- pasid_state = pasid == PASID_DISABLED ?
- pasid : pasid | MSR_IA32_PASID_VALID;
-
- /*
- * No need to hold fregs_lock() since the task's fpstate won't
- * be changed by others (e.g. ptrace) while the task is being
- * switched to or is in IPI.
- */
- if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {
- /* The MSR is active and can be directly updated. */
- wrmsrl(MSR_IA32_PASID, pasid_state);
- } else {
- struct fpu *fpu = ¤t->thread.fpu;
- struct ia32_pasid_state *ppasid_state;
- struct xregs_state *xsave;
-
- /*
- * The CPU's xstate registers are not currently active. Just
- * update the PASID state in the memory buffer here. The
- * PASID MSR will be loaded when returning to user mode.
- */
- xsave = &fpu->state.xsave;
- xsave->header.xfeatures |= XFEATURE_MASK_PASID;
- ppasid_state = get_xsave_addr(xsave, XFEATURE_PASID);
- /*
- * Since XFEATURE_MASK_PASID is set in xfeatures, ppasid_state
- * won't be NULL and no need to check its value.
- *
- * Only update the task's PASID state when it's different
- * from the mm's pasid.
- */
- if (ppasid_state->pasid != pasid_state) {
- /*
- * Invalid fpregs so that state restoring will pick up
- * the PASID state.
- */
- __fpu_invalidate_fpregs_state(fpu);
- ppasid_state->pasid = pasid_state;
- }
- }
- }
- #endif /* CONFIG_IOMMU_SUPPORT */
int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
int force_sig_pkuerr(void __user *addr, u32 pkey);
+ int force_sig_perf(void __user *addr, u32 type, u64 sig_data);
int force_sig_ptrace_errno_trap(int errno, void __user *addr);
#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
#define SEND_SIG_PRIV ((struct kernel_siginfo *) 1)
+static inline int __on_sig_stack(unsigned long sp)
+{
+#ifdef CONFIG_STACK_GROWSUP
+ return sp >= current->sas_ss_sp &&
+ sp - current->sas_ss_sp < current->sas_ss_size;
+#else
+ return sp > current->sas_ss_sp &&
+ sp - current->sas_ss_sp <= current->sas_ss_size;
+#endif
+}
+
/*
* True if we are on the alternate signal stack.
*/
if (current->sas_ss_flags & SS_AUTODISARM)
return 0;
-#ifdef CONFIG_STACK_GROWSUP
- return sp >= current->sas_ss_sp &&
- sp - current->sas_ss_sp < current->sas_ss_size;
-#else
- return sp > current->sas_ss_sp &&
- sp - current->sas_ss_sp <= current->sas_ss_size;
-#endif
+ return __on_sig_stack(sp);
}
static inline int sas_ss_flags(unsigned long sp)
projects / linux-2.6-microblaze.git / commitdiff