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Diffstat (limited to 'arch/x86/kernel/fpu/signal.c')
-rw-r--r--arch/x86/kernel/fpu/signal.c37
1 files changed, 21 insertions, 16 deletions
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 83c23c230b4c..fb639e70048f 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -155,7 +155,8 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf)
*/
int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
{
- struct xregs_state *xsave = &current->thread.fpu.state.xsave;
+ struct fpu *fpu = &current->thread.fpu;
+ struct xregs_state *xsave = &fpu->state.xsave;
struct task_struct *tsk = current;
int ia32_fxstate = (buf != buf_fx);
@@ -170,13 +171,13 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
sizeof(struct user_i387_ia32_struct), NULL,
(struct _fpstate_32 __user *) buf) ? -1 : 1;
- if (fpregs_active() || using_compacted_format()) {
+ if (fpu->initialized || using_compacted_format()) {
/* Save the live register state to the user directly. */
if (copy_fpregs_to_sigframe(buf_fx))
return -1;
/* Update the thread's fxstate to save the fsave header. */
if (ia32_fxstate)
- copy_fxregs_to_kernel(&tsk->thread.fpu);
+ copy_fxregs_to_kernel(fpu);
} else {
/*
* It is a *bug* if kernel uses compacted-format for xsave
@@ -189,7 +190,7 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
return -1;
}
- fpstate_sanitize_xstate(&tsk->thread.fpu);
+ fpstate_sanitize_xstate(fpu);
if (__copy_to_user(buf_fx, xsave, fpu_user_xstate_size))
return -1;
}
@@ -213,8 +214,11 @@ sanitize_restored_xstate(struct task_struct *tsk,
struct xstate_header *header = &xsave->header;
if (use_xsave()) {
- /* These bits must be zero. */
- memset(header->reserved, 0, 48);
+ /*
+ * 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.
+ */
/*
* Init the state that is not present in the memory
@@ -223,7 +227,7 @@ sanitize_restored_xstate(struct task_struct *tsk,
if (fx_only)
header->xfeatures = XFEATURE_MASK_FPSSE;
else
- header->xfeatures &= (xfeatures_mask & xfeatures);
+ header->xfeatures &= xfeatures;
}
if (use_fxsr()) {
@@ -279,7 +283,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
if (!access_ok(VERIFY_READ, buf, size))
return -EACCES;
- fpu__activate_curr(fpu);
+ fpu__initialize(fpu);
if (!static_cpu_has(X86_FEATURE_FPU))
return fpregs_soft_set(current, NULL,
@@ -307,28 +311,29 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
/*
* For 32-bit frames with fxstate, copy the user state to the
* thread's fpu state, reconstruct fxstate from the fsave
- * header. Sanitize the copied state etc.
+ * header. Validate and sanitize the copied state.
*/
struct fpu *fpu = &tsk->thread.fpu;
struct user_i387_ia32_struct env;
int err = 0;
/*
- * Drop the current fpu which clears fpu->fpstate_active. This ensures
+ * Drop the current fpu which clears fpu->initialized. This ensures
* that any context-switch during the copy of the new state,
* avoids the intermediate state from getting restored/saved.
* Thus avoiding the new restored state from getting corrupted.
* We will be ready to restore/save the state only after
- * fpu->fpstate_active is again set.
+ * fpu->initialized is again set.
*/
fpu__drop(fpu);
if (using_compacted_format()) {
- err = copyin_to_xsaves(NULL, buf_fx,
- &fpu->state.xsave);
+ err = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
} else {
- err = __copy_from_user(&fpu->state.xsave,
- buf_fx, state_size);
+ err = __copy_from_user(&fpu->state.xsave, buf_fx, state_size);
+
+ if (!err && state_size > offsetof(struct xregs_state, header))
+ err = validate_xstate_header(&fpu->state.xsave.header);
}
if (err || __copy_from_user(&env, buf, sizeof(env))) {
@@ -339,7 +344,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
sanitize_restored_xstate(tsk, &env, xfeatures, fx_only);
}
- fpu->fpstate_active = 1;
+ fpu->initialized = 1;
preempt_disable();
fpu__restore(fpu);
preempt_enable();