diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 73cb07b6f1e2791e271fc9049fd78a34dcf034f1..58cdf1837d440c00cc527097fcac6772d485fe2c 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -326,9 +326,12 @@ static inline void os_xrstor(struct xregs_state *xstate, u64 mask) * We don't use modified optimization because xrstor/xrstors might track * a different application. * - * We don't use compacted format xsave area for - * backward compatibility for old applications which don't understand - * compacted format of xsave area. + * We don't use compacted format xsave area for backward compatibility for + * old applications which don't understand the compacted format of the + * xsave area. + * + * The caller has to zero buf::header before calling this because XSAVE* + * does not touch the reserved fields in the header. */ static inline int xsave_to_user_sigframe(struct xregs_state __user *buf) { @@ -342,14 +345,6 @@ static inline int xsave_to_user_sigframe(struct xregs_state __user *buf) u32 hmask = mask >> 32; int err; - /* - * Clear the xsave header first, so that reserved fields are - * initialized to zero. - */ - err = __clear_user(&buf->header, sizeof(buf->header)); - if (unlikely(err)) - return -EFAULT; - stac(); XSTATE_OP(XSAVE, buf, lmask, hmask, err); clac(); diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index cd96f5ce0ca7ada8f88ef58af748d7f240591537..91c1e68e5fca59528415c8761af1530298ec8fd5 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -189,6 +189,18 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size) if (!access_ok(buf, size)) return -EACCES; + + if (use_xsave()) { + struct xregs_state __user *xbuf = buf_fx; + + /* + * Clear the xsave header first, so that reserved fields are + * initialized to zero. + */ + ret = __clear_user(&xbuf->header, sizeof(xbuf->header)); + if (unlikely(ret)) + return ret; + } retry: /* * Load the FPU registers if they are not valid for the current task.