diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2021-06-23 14:01:46 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-06-23 17:49:47 +0200 |
| commit | 5a32fac8dbe8adc08c10e2c8770c95aebfc627cd (patch) | |
| tree | c2050a16b5522c3a2638bd136b2437022c033235 /arch/x86/kernel/fpu/regset.c | |
| parent | afac9e894364418731d1d7e66c1118b31fd130e8 (diff) | |
x86/fpu/regset: Move fpu__read_begin() into regset
The function can only be used from the regset get() callbacks safely. So
there is no reason to have it globally exposed.
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/20210623121453.234942936@linutronix.de
Diffstat (limited to 'arch/x86/kernel/fpu/regset.c')
| -rw-r--r-- | arch/x86/kernel/fpu/regset.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index 4b799e42ebc7..937adf702b37 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -28,6 +28,22 @@ int regset_xregset_fpregs_active(struct task_struct *target, const struct user_r return 0; } +/* + * The regset get() functions are invoked from: + * + * - coredump to dump the current task's fpstate. If the current task + * owns the FPU then the memory state has to be synchronized and the + * FPU register state preserved. Otherwise fpstate is already in sync. + * + * - ptrace to dump fpstate of a stopped task, in which case the registers + * have already been saved to fpstate on context switch. + */ +static void sync_fpstate(struct fpu *fpu) +{ + if (fpu == ¤t->thread.fpu) + fpu__save(fpu); +} + int xfpregs_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { @@ -36,7 +52,7 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset, if (!cpu_feature_enabled(X86_FEATURE_FXSR)) return -ENODEV; - fpu__prepare_read(fpu); + sync_fpstate(fpu); if (!use_xsave()) { return membuf_write(&to, &fpu->state.fxsave, @@ -96,7 +112,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, if (!cpu_feature_enabled(X86_FEATURE_XSAVE)) return -ENODEV; - fpu__prepare_read(fpu); + sync_fpstate(fpu); copy_xstate_to_uabi_buf(to, &fpu->state.xsave, XSTATE_COPY_XSAVE); return 0; @@ -287,7 +303,7 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset, struct user_i387_ia32_struct env; struct fxregs_state fxsave, *fx; - fpu__prepare_read(fpu); + sync_fpstate(fpu); if (!cpu_feature_enabled(X86_FEATURE_FPU)) return fpregs_soft_get(target, regset, to); |