diff options
author | Suresh Siddha <suresh.b.siddha@intel.com> | 2008-07-29 17:29:25 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-07-30 17:49:27 (GMT) |
commit | c37b5efea43f9e500363f9973dd00e3d2cdcc685 (patch) | |
tree | 9ce635f1672099dafcd78e535b4ea18d80235d8f /arch/x86/kernel/i387.c | |
parent | bdd8caba5ed5bb7ee21c9f061597284ffeb280bf (diff) | |
download | linux-fsl-qoriq-c37b5efea43f9e500363f9973dd00e3d2cdcc685.tar.xz |
x86, xsave: save/restore the extended state context in sigframe
On cpu's supporting xsave/xrstor, fpstate pointer in the sigcontext, will
include the extended state information along with fpstate information. Presence
of extended state information is indicated by the presence
of FP_XSTATE_MAGIC1 at fpstate.sw_reserved.magic1 and FP_XSTATE_MAGIC2
at fpstate + (fpstate.sw_reserved.extended_size - FP_XSTATE_MAGIC2_SIZE).
Extended feature bit mask that is saved in the memory layout is represented
by the fpstate.sw_reserved.xstate_bv
For RT signal frames, UC_FP_XSTATE in the uc_flags also indicate the
presence of extended state information in the sigcontext's fpstate
pointer.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/i387.c')
-rw-r--r-- | arch/x86/kernel/i387.c | 82 |
1 files changed, 76 insertions, 6 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 7daf3a0..cbb9dc4 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -26,6 +26,7 @@ # define _fpstate_ia32 _fpstate # define _xstate_ia32 _xstate # define sig_xstate_ia32_size sig_xstate_size +# define fx_sw_reserved_ia32 fx_sw_reserved # define user_i387_ia32_struct user_i387_struct # define user32_fxsr_struct user_fxsr_struct #endif @@ -447,12 +448,30 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf) if (err) return -1; - if (__copy_to_user(&buf->_fxsr_env[0], fx, - sizeof(struct i387_fxsave_struct))) + if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size)) return -1; return 1; } +static int save_i387_xsave(void __user *buf) +{ + struct _fpstate_ia32 __user *fx = buf; + int err = 0; + + if (save_i387_fxsave(fx) < 0) + return -1; + + err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32, + sizeof(struct _fpx_sw_bytes)); + err |= __put_user(FP_XSTATE_MAGIC2, + (__u32 __user *) (buf + sig_xstate_ia32_size + - FP_XSTATE_MAGIC2_SIZE)); + if (err) + return -1; + + return 1; +} + int save_i387_xstate_ia32(void __user *buf) { struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf; @@ -477,6 +496,8 @@ int save_i387_xstate_ia32(void __user *buf) unlazy_fpu(tsk); + if (cpu_has_xsave) + return save_i387_xsave(fp); if (cpu_has_fxsr) return save_i387_fxsave(fp); else @@ -491,14 +512,15 @@ static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf) sizeof(struct i387_fsave_struct)); } -static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf) +static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf, + unsigned int size) { struct task_struct *tsk = current; struct user_i387_ia32_struct env; int err; err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0], - sizeof(struct i387_fxsave_struct)); + size); /* mxcsr reserved bits must be masked to zero for security reasons */ tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask; if (err || __copy_from_user(&env, buf, sizeof(env))) @@ -508,6 +530,51 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf) return 0; } +static int restore_i387_xsave(void __user *buf) +{ + struct _fpx_sw_bytes fx_sw_user; + struct _fpstate_ia32 __user *fx_user = + ((struct _fpstate_ia32 __user *) buf); + struct i387_fxsave_struct __user *fx = + (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0]; + struct xsave_hdr_struct *xsave_hdr = + ¤t->thread.xstate->xsave.xsave_hdr; + unsigned int lmask, hmask; + int err; + + if (check_for_xstate(fx, buf, &fx_sw_user)) + goto fx_only; + + lmask = fx_sw_user.xstate_bv; + hmask = fx_sw_user.xstate_bv >> 32; + + err = restore_i387_fxsave(buf, fx_sw_user.xstate_size); + + xsave_hdr->xstate_bv &= (pcntxt_lmask | (((u64) pcntxt_hmask) << 32)); + /* + * These bits must be zero. + */ + xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0; + + /* + * Init the state that is not present in the memory layout + * and enabled by the OS. + */ + lmask = ~(pcntxt_lmask & ~lmask); + hmask = ~(pcntxt_hmask & ~hmask); + xsave_hdr->xstate_bv &= (lmask | (((u64) hmask) << 32)); + + return err; +fx_only: + /* + * Couldn't find the extended state information in the memory + * layout. Restore the FP/SSE and init the other extended state + * enabled by the OS. + */ + xsave_hdr->xstate_bv = XSTATE_FPSSE; + return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct)); +} + int restore_i387_xstate_ia32(void __user *buf) { int err; @@ -535,8 +602,11 @@ int restore_i387_xstate_ia32(void __user *buf) } if (HAVE_HWFP) { - if (cpu_has_fxsr) - err = restore_i387_fxsave(fp); + if (cpu_has_xsave) + err = restore_i387_xsave(buf); + else if (cpu_has_fxsr) + err = restore_i387_fxsave(fp, sizeof(struct + i387_fxsave_struct)); else err = restore_i387_fsave(fp); } else { |