diff --git a/arch/x86/include/asm/mpx.h b/arch/x86/include/asm/mpx.h
index f3c1b71d4faeeb141164941b683553481be5d2c8..39f2d0ffe1e203d2a4fe0a4761bb20337057951a 100644
--- a/arch/x86/include/asm/mpx.h
+++ b/arch/x86/include/asm/mpx.h
@@ -60,8 +60,8 @@
#ifdef CONFIG_X86_INTEL_MPX
siginfo_t *mpx_generate_siginfo(struct pt_regs *regs,
- struct xregs_state *xsave_buf);
-int mpx_handle_bd_fault(struct xregs_state *xsave_buf);
+ struct task_struct *tsk);
+int mpx_handle_bd_fault(struct task_struct *tsk);
static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
{
return (mm->bd_addr != MPX_INVALID_BOUNDS_DIR);
@@ -78,11 +78,11 @@ void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long start, unsigned long end);
#else
static inline siginfo_t *mpx_generate_siginfo(struct pt_regs *regs,
- struct xregs_state *xsave_buf)
+ struct task_struct *tsk)
{
return NULL;
}
-static inline int mpx_handle_bd_fault(struct xregs_state *xsave_buf)
+static inline int mpx_handle_bd_fault(struct task_struct *tsk)
{
return -EINVAL;
}
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a2510f2301951a1c7b3b82a1b32b4687fcf501cf..42f15314b3616d3fb0ba81c0a39bb5fa846b493e 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -59,6 +59,7 @@
#include <asm/fixmap.h>
#include <asm/mach_traps.h>
#include <asm/alternative.h>
+#include <asm/fpu/xstate.h>
#include <asm/mpx.h>
#ifdef CONFIG_X86_64
@@ -371,9 +372,8 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
{
struct task_struct *tsk = current;
- struct xregs_state *xsave_buf;
enum ctx_state prev_state;
- struct bndcsr *bndcsr;
+ const struct bndcsr *bndcsr;
siginfo_t *info;
prev_state = exception_enter();
@@ -392,12 +392,11 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
/*
* We need to look at BNDSTATUS to resolve this exception.
- * It is not directly accessible, though, so we need to
- * do an xsave and then pull it out of the xsave buffer.
+ * A NULL here might mean that it is in its 'init state',
+ * which is all zeros which indicates MPX was not
+ * responsible for the exception.
*/
- copy_fpregs_to_fpstate(&tsk->thread.fpu);
- xsave_buf = &(tsk->thread.fpu.state.xsave);
- bndcsr = get_xsave_addr(xsave_buf, XSTATE_BNDCSR);
+ bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR);
if (!bndcsr)
goto exit_trap;
@@ -408,11 +407,11 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
*/
switch (bndcsr->bndstatus & MPX_BNDSTA_ERROR_CODE) {
case 2: /* Bound directory has invalid entry. */
- if (mpx_handle_bd_fault(xsave_buf))
+ if (mpx_handle_bd_fault(tsk))
goto exit_trap;
break; /* Success, it was handled */
case 1: /* Bound violation. */
- info = mpx_generate_siginfo(regs, xsave_buf);
+ info = mpx_generate_siginfo(regs, tsk);
if (IS_ERR(info)) {
/*
* We failed to decode the MPX instruction. Act as if
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 2e0dfd39bd22803a0a997aa36cfab67528f1cf6f..9d67e230b4fb70c36114aa2da0f6a051e81d64f1 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -272,9 +272,9 @@ static int mpx_insn_decode(struct insn *insn,
* The caller is expected to kfree() the returned siginfo_t.
*/
siginfo_t *mpx_generate_siginfo(struct pt_regs *regs,
- struct xregs_state *xsave_buf)
+ struct task_struct *tsk)
{
- struct bndreg *bndregs, *bndreg;
+ const struct bndreg *bndregs, *bndreg;
siginfo_t *info = NULL;
struct insn insn;
uint8_t bndregno;
@@ -294,8 +294,8 @@ siginfo_t *mpx_generate_siginfo(struct pt_regs *regs,
err = -EINVAL;
goto err_out;
}
- /* get the bndregs _area_ of the xsave structure */
- bndregs = get_xsave_addr(xsave_buf, XSTATE_BNDREGS);
+ /* get bndregs field from current task's xsave area */
+ bndregs = get_xsave_field_ptr(XSTATE_BNDREGS);
if (!bndregs) {
err = -EINVAL;
goto err_out;
@@ -342,7 +342,7 @@ siginfo_t *mpx_generate_siginfo(struct pt_regs *regs,
static __user void *task_get_bounds_dir(struct task_struct *tsk)
{
- struct bndcsr *bndcsr;
+ const struct bndcsr *bndcsr;
if (!cpu_feature_enabled(X86_FEATURE_MPX))
return MPX_INVALID_BOUNDS_DIR;
@@ -357,8 +357,7 @@ static __user void *task_get_bounds_dir(struct task_struct *tsk)
* The bounds directory pointer is stored in a register
* only accessible if we first do an xsave.
*/
- copy_fpregs_to_fpstate(&tsk->thread.fpu);
- bndcsr = get_xsave_addr(&tsk->thread.fpu.state.xsave, XSTATE_BNDCSR);
+ bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR);
if (!bndcsr)
return MPX_INVALID_BOUNDS_DIR;
@@ -389,9 +388,10 @@ int mpx_enable_management(struct task_struct *tsk)
* directory into XSAVE/XRSTOR Save Area and enable MPX through
* XRSTOR instruction.
*
- * copy_xregs_to_kernel() is expected to be very expensive. Storing the bounds
- * directory here means that we do not have to do xsave in the unmap
- * path; we can just use mm->bd_addr instead.
+ * The copy_xregs_to_kernel() beneath get_xsave_field_ptr() is
+ * expected to be relatively expensive. Storing the bounds
+ * directory here means that we do not have to do xsave in the
+ * unmap path; we can just use mm->bd_addr instead.
*/
bd_base = task_get_bounds_dir(tsk);
down_write(&mm->mmap_sem);
@@ -497,12 +497,12 @@ static int allocate_bt(long __user *bd_entry)
* bound table is 16KB. With 64-bit mode, the size of BD is 2GB,
* and the size of each bound table is 4MB.
*/
-static int do_mpx_bt_fault(struct xregs_state *xsave_buf)
+static int do_mpx_bt_fault(struct task_struct *tsk)
{
unsigned long bd_entry, bd_base;
- struct bndcsr *bndcsr;
+ const struct bndcsr *bndcsr;
- bndcsr = get_xsave_addr(xsave_buf, XSTATE_BNDCSR);
+ bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR);
if (!bndcsr)
return -EINVAL;
/*
@@ -525,7 +525,7 @@ static int do_mpx_bt_fault(struct xregs_state *xsave_buf)
return allocate_bt((long __user *)bd_entry);
}
-int mpx_handle_bd_fault(struct xregs_state *xsave_buf)
+int mpx_handle_bd_fault(struct task_struct *tsk)
{
/*
* Userspace never asked us to manage the bounds tables,
@@ -534,7 +534,7 @@ int mpx_handle_bd_fault(struct xregs_state *xsave_buf)
if (!kernel_managing_mpx_tables(current->mm))
return -EINVAL;
- if (do_mpx_bt_fault(xsave_buf)) {
+ if (do_mpx_bt_fault(tsk)) {
force_sig(SIGSEGV, current);
/*
* The force_sig() is essentially "handling" this