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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-10-20 00:10:27 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-10-20 00:10:27 -0300
commitd0b2f91bede3bd5e3d24dd6803e56eee959c1797 (patch)
tree7fee4ab0509879c373c4f2cbd5b8a5be5b4041ee /arch/x86/kernel/fpu/signal.c
parente914f8eb445e8f74b00303c19c2ffceaedd16a05 (diff)
Linux-libre 4.8.2-gnupck-4.8.2-gnu
Diffstat (limited to 'arch/x86/kernel/fpu/signal.c')
-rw-r--r--arch/x86/kernel/fpu/signal.c58
1 files changed, 41 insertions, 17 deletions
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 31c6a6050..a184c210e 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -8,8 +8,10 @@
#include <asm/fpu/internal.h>
#include <asm/fpu/signal.h>
#include <asm/fpu/regset.h>
+#include <asm/fpu/xstate.h>
#include <asm/sigframe.h>
+#include <asm/trace/fpu.h>
static struct _fpx_sw_bytes fx_sw_reserved, fx_sw_reserved_ia32;
@@ -31,7 +33,7 @@ static inline int check_for_xstate(struct fxregs_state __user *buf,
/* Check for the first magic field and other error scenarios. */
if (fx_sw->magic1 != FP_XSTATE_MAGIC1 ||
fx_sw->xstate_size < min_xstate_size ||
- fx_sw->xstate_size > xstate_size ||
+ fx_sw->xstate_size > fpu_user_xstate_size ||
fx_sw->xstate_size > fx_sw->extended_size)
return -1;
@@ -88,7 +90,8 @@ static inline int save_xstate_epilog(void __user *buf, int ia32_frame)
if (!use_xsave())
return err;
- err |= __put_user(FP_XSTATE_MAGIC2, (__u32 *)(buf + xstate_size));
+ err |= __put_user(FP_XSTATE_MAGIC2,
+ (__u32 *)(buf + fpu_user_xstate_size));
/*
* Read the xfeatures which we copied (directly from the cpu or
@@ -125,7 +128,7 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf)
else
err = copy_fregs_to_user((struct fregs_state __user *) buf);
- if (unlikely(err) && __clear_user(buf, xstate_size))
+ if (unlikely(err) && __clear_user(buf, fpu_user_xstate_size))
err = -EFAULT;
return err;
}
@@ -156,8 +159,8 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
struct task_struct *tsk = current;
int ia32_fxstate = (buf != buf_fx);
- ia32_fxstate &= (config_enabled(CONFIG_X86_32) ||
- config_enabled(CONFIG_IA32_EMULATION));
+ ia32_fxstate &= (IS_ENABLED(CONFIG_X86_32) ||
+ IS_ENABLED(CONFIG_IA32_EMULATION));
if (!access_ok(VERIFY_WRITE, buf, size))
return -EACCES;
@@ -167,7 +170,7 @@ 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()) {
+ if (fpregs_active() || using_compacted_format()) {
/* Save the live register state to the user directly. */
if (copy_fpregs_to_sigframe(buf_fx))
return -1;
@@ -175,8 +178,19 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
if (ia32_fxstate)
copy_fxregs_to_kernel(&tsk->thread.fpu);
} else {
+ /*
+ * It is a *bug* if kernel uses compacted-format for xsave
+ * area and we copy it out directly to a signal frame. It
+ * should have been handled above by saving the registers
+ * directly.
+ */
+ if (boot_cpu_has(X86_FEATURE_XSAVES)) {
+ WARN_ONCE(1, "x86/fpu: saving compacted-format xsave area to a signal frame!\n");
+ return -1;
+ }
+
fpstate_sanitize_xstate(&tsk->thread.fpu);
- if (__copy_to_user(buf_fx, xsave, xstate_size))
+ if (__copy_to_user(buf_fx, xsave, fpu_user_xstate_size))
return -1;
}
@@ -250,12 +264,12 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
int ia32_fxstate = (buf != buf_fx);
struct task_struct *tsk = current;
struct fpu *fpu = &tsk->thread.fpu;
- int state_size = xstate_size;
+ int state_size = fpu_kernel_xstate_size;
u64 xfeatures = 0;
int fx_only = 0;
- ia32_fxstate &= (config_enabled(CONFIG_X86_32) ||
- config_enabled(CONFIG_IA32_EMULATION));
+ ia32_fxstate &= (IS_ENABLED(CONFIG_X86_32) ||
+ IS_ENABLED(CONFIG_IA32_EMULATION));
if (!buf) {
fpu__clear(fpu);
@@ -282,6 +296,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
*/
state_size = sizeof(struct fxregs_state);
fx_only = 1;
+ trace_x86_fpu_xstate_check_failed(fpu);
} else {
state_size = fx_sw_user.xstate_size;
xfeatures = fx_sw_user.xfeatures;
@@ -308,9 +323,17 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
*/
fpu__drop(fpu);
- if (__copy_from_user(&fpu->state.xsave, buf_fx, state_size) ||
- __copy_from_user(&env, buf, sizeof(env))) {
+ if (using_compacted_format()) {
+ err = copyin_to_xsaves(NULL, buf_fx,
+ &fpu->state.xsave);
+ } else {
+ err = __copy_from_user(&fpu->state.xsave,
+ buf_fx, state_size);
+ }
+
+ if (err || __copy_from_user(&env, buf, sizeof(env))) {
fpstate_init(&fpu->state);
+ trace_x86_fpu_init_state(fpu);
err = -1;
} else {
sanitize_restored_xstate(tsk, &env, xfeatures, fx_only);
@@ -341,7 +364,8 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
static inline int xstate_sigframe_size(void)
{
- return use_xsave() ? xstate_size + FP_XSTATE_MAGIC2_SIZE : xstate_size;
+ return use_xsave() ? fpu_user_xstate_size + FP_XSTATE_MAGIC2_SIZE :
+ fpu_user_xstate_size;
}
/*
@@ -385,15 +409,15 @@ fpu__alloc_mathframe(unsigned long sp, int ia32_frame,
*/
void fpu__init_prepare_fx_sw_frame(void)
{
- int size = xstate_size + FP_XSTATE_MAGIC2_SIZE;
+ int size = fpu_user_xstate_size + FP_XSTATE_MAGIC2_SIZE;
fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1;
fx_sw_reserved.extended_size = size;
fx_sw_reserved.xfeatures = xfeatures_mask;
- fx_sw_reserved.xstate_size = xstate_size;
+ fx_sw_reserved.xstate_size = fpu_user_xstate_size;
- if (config_enabled(CONFIG_IA32_EMULATION) ||
- config_enabled(CONFIG_X86_32)) {
+ if (IS_ENABLED(CONFIG_IA32_EMULATION) ||
+ IS_ENABLED(CONFIG_X86_32)) {
int fsave_header_size = sizeof(struct fregs_state);
fx_sw_reserved_ia32 = fx_sw_reserved;