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| author | Thomas Gleixner <tglx@linutronix.de> | 2021-06-23 14:01:44 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-06-23 17:49:47 +0200 |
| commit | 3f7f75634ccefefcc929696f346db7a748e78f79 (patch) | |
| tree | 777eae2ecb9d67f1d468532794ddf565a7e5cafd /arch/x86/kernel/fpu | |
| parent | x86/fpu: Use copy_xstate_to_uabi_buf() in xfpregs_get() (diff) | |
| download | linux-3f7f75634ccefefcc929696f346db7a748e78f79.tar.xz linux-3f7f75634ccefefcc929696f346db7a748e78f79.zip | |
x86/fpu: Use copy_xstate_to_uabi_buf() in fpregs_get()
Use the new functionality of copy_xstate_to_uabi_buf() to retrieve the
FX state when XSAVE* is in use. This avoids to overwrite the FPU state
buffer with fpstate_sanitize_xstate() which is error prone and duplicated
code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210623121453.014441775@linutronix.de
Diffstat (limited to 'arch/x86/kernel/fpu')
| -rw-r--r-- | arch/x86/kernel/fpu/regset.c | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index ccbe25f6627d..4b799e42ebc7 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -210,10 +210,10 @@ static inline u32 twd_fxsr_to_i387(struct fxregs_state *fxsave) * FXSR floating point environment conversions. */ -void -convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk) +static void __convert_from_fxsr(struct user_i387_ia32_struct *env, + struct task_struct *tsk, + struct fxregs_state *fxsave) { - struct fxregs_state *fxsave = &tsk->thread.fpu.state.fxsave; struct _fpreg *to = (struct _fpreg *) &env->st_space[0]; struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0]; int i; @@ -247,6 +247,12 @@ convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk) memcpy(&to[i], &from[i], sizeof(to[0])); } +void +convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk) +{ + __convert_from_fxsr(env, tsk, &tsk->thread.fpu.state.fxsave); +} + void convert_to_fxsr(struct fxregs_state *fxsave, const struct user_i387_ia32_struct *env) @@ -279,25 +285,29 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset, { struct fpu *fpu = &target->thread.fpu; struct user_i387_ia32_struct env; + struct fxregs_state fxsave, *fx; fpu__prepare_read(fpu); - if (!boot_cpu_has(X86_FEATURE_FPU)) + if (!cpu_feature_enabled(X86_FEATURE_FPU)) return fpregs_soft_get(target, regset, to); - if (!boot_cpu_has(X86_FEATURE_FXSR)) { + if (!cpu_feature_enabled(X86_FEATURE_FXSR)) { return membuf_write(&to, &fpu->state.fsave, sizeof(struct fregs_state)); } - fpstate_sanitize_xstate(fpu); + if (use_xsave()) { + struct membuf mb = { .p = &fxsave, .left = sizeof(fxsave) }; - if (to.left == sizeof(env)) { - convert_from_fxsr(to.p, target); - return 0; + /* Handle init state optimized xstate correctly */ + copy_xstate_to_uabi_buf(mb, &fpu->state.xsave, XSTATE_COPY_FP); + fx = &fxsave; + } else { + fx = &fpu->state.fxsave; } - convert_from_fxsr(&env, target); + __convert_from_fxsr(&env, target, fx); return membuf_write(&to, &env, sizeof(env)); } |