From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Tony Luck <tony.luck@intel.com>,
Yu-cheng Yu <yu-cheng.yu@intel.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Borislav Petkov <bp@suse.de>,
Peter Zijlstra <peterz@infradead.org>,
Kan Liang <kan.liang@linux.intel.com>,
"Chang Seok Bae" <chang.seok.bae@intel.com>,
Megha Dey <megha.dey@linux.intel.com>,
Oliver Sang <oliver.sang@intel.com>
Subject: [patch V4 20/65] x86/fpu: Move fpu__write_begin() to regset
Date: Wed, 23 Jun 2021 14:01:47 +0200 [thread overview]
Message-ID: <20210623121453.328652975@linutronix.de> (raw)
In-Reply-To: 20210623120127.327154589@linutronix.de
The only usecase for fpu__write_begin is the set() callback of regset, so
the function is pointlessly global.
Move it to the regset code and rename it to fpu_force_restore() which is
exactly decribing what the function does.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
---
arch/x86/include/asm/fpu/internal.h | 1 -
arch/x86/kernel/fpu/core.c | 24 ------------------------
arch/x86/kernel/fpu/regset.c | 25 ++++++++++++++++++++++---
3 files changed, 22 insertions(+), 28 deletions(-)
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -26,7 +26,6 @@
/*
* High level FPU state handling functions:
*/
-extern void fpu__prepare_write(struct fpu *fpu);
extern void fpu__save(struct fpu *fpu);
extern int fpu__restore_sig(void __user *buf, int ia32_frame);
extern void fpu__drop(struct fpu *fpu);
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -282,30 +282,6 @@ static void fpu__initialize(struct fpu *
}
/*
- * This function must be called before we write a task's fpstate.
- *
- * Invalidate any cached FPU registers.
- *
- * After this function call, after registers in the fpstate are
- * modified and the child task has woken up, the child task will
- * restore the modified FPU state from the modified context. If we
- * didn't clear its cached status here then the cached in-registers
- * state pending on its former CPU could be restored, corrupting
- * the modifications.
- */
-void fpu__prepare_write(struct fpu *fpu)
-{
- /*
- * Only stopped child tasks can be used to modify the FPU
- * state in the fpstate buffer:
- */
- WARN_ON_FPU(fpu == ¤t->thread.fpu);
-
- /* Invalidate any cached state: */
- __fpu_invalidate_fpregs_state(fpu);
-}
-
-/*
* Drops current FPU state: deactivates the fpregs and
* the fpstate. NOTE: it still leaves previous contents
* in the fpregs in the eager-FPU case.
--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c
@@ -44,6 +44,25 @@ static void sync_fpstate(struct fpu *fpu
fpu__save(fpu);
}
+/*
+ * Invalidate cached FPU registers before modifying the stopped target
+ * task's fpstate.
+ *
+ * This forces the target task on resume to restore the FPU registers from
+ * modified fpstate. Otherwise the task might skip the restore and operate
+ * with the cached FPU registers which discards the modifications.
+ */
+static void fpu_force_restore(struct fpu *fpu)
+{
+ /*
+ * Only stopped child tasks can be used to modify the FPU
+ * state in the fpstate buffer:
+ */
+ WARN_ON_FPU(fpu == ¤t->thread.fpu);
+
+ __fpu_invalidate_fpregs_state(fpu);
+}
+
int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
struct membuf to)
{
@@ -88,7 +107,7 @@ int xfpregs_set(struct task_struct *targ
if (newstate.mxcsr & ~mxcsr_feature_mask)
return -EINVAL;
- fpu__prepare_write(fpu);
+ fpu_force_restore(fpu);
/* Copy the state */
memcpy(&fpu->state.fxsave, &newstate, sizeof(newstate));
@@ -146,7 +165,7 @@ int xstateregs_set(struct task_struct *t
}
}
- fpu__prepare_write(fpu);
+ fpu_force_restore(fpu);
ret = copy_kernel_to_xstate(&fpu->state.xsave, kbuf ?: tmpbuf);
out:
@@ -346,7 +365,7 @@ int fpregs_set(struct task_struct *targe
if (ret)
return ret;
- fpu__prepare_write(fpu);
+ fpu_force_restore(fpu);
if (cpu_feature_enabled(X86_FEATURE_FXSR))
convert_to_fxsr(&fpu->state.fxsave, &env);
next prev parent reply other threads:[~2021-06-23 12:24 UTC|newest]
Thread overview: 142+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 12:01 [patch V4 00/65] x86/fpu: Spring cleaning and PKRU sanitizing Thomas Gleixner
2021-06-23 12:01 ` [patch V4 01/65] x86/fpu: Fix copy_xstate_to_kernel() gap handling Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 02/65] x86/pkeys: Revert a5eff7259790 ("x86/pkeys: Add PKRU value to init_fpstate") Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 03/65] x86/fpu: Mark various FPU states __ro_after_init Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] x86/fpu: Mark various FPU state variables __ro_after_init tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 04/65] x86/fpu: Make xfeatures_mask_all __ro_after_init Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 05/65] x86/fpu: Get rid of fpu__get_supported_xfeatures_mask() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 06/65] x86/fpu: Remove unused get_xsave_field_ptr() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 07/65] x86/fpu: Move inlines where they belong Thomas Gleixner
2021-06-23 18:43 ` Bae, Chang Seok
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 08/65] x86/fpu: Limit xstate copy size in xstateregs_set() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 09/65] x86/fpu: Sanitize xstateregs_set() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2022-07-14 4:04 ` [patch V4 09/65] " Andrei Vagin
2022-07-25 17:47 ` Dave Hansen
2022-07-25 17:57 ` Andrei Vagin
2022-07-25 21:26 ` Dave Hansen
2022-07-28 23:32 ` Chang S. Bae
2022-08-05 12:12 ` Andrei Vagin
2022-08-05 18:24 ` Chang S. Bae
2022-08-05 18:35 ` Dave Hansen
2021-06-23 12:01 ` [patch V4 10/65] x86/fpu: Reject invalid MXCSR values in copy_kernel_to_xstate() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 11/65] x86/fpu: Simplify PTRACE_GETREGS code Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Dave Hansen
2021-06-23 12:01 ` [patch V4 12/65] x86/fpu: Rewrite xfpregs_set() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Andy Lutomirski
2021-06-23 12:01 ` [patch V4 13/65] x86/fpu: Fail ptrace() requests that try to set invalid MXCSR values Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Andy Lutomirski
2021-06-23 12:01 ` [patch V4 14/65] x86/fpu: Clean up fpregs_set() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Andy Lutomirski
2021-06-23 12:01 ` [patch V4 15/65] x86/fpu: Make copy_xstate_to_kernel() usable for [x]fpregs_get() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-24 15:09 ` [PATCH] x86/fpu/xstate: Clear xstate header in copy_xstate_to_uabi_buf() again Thomas Gleixner
2021-06-24 15:41 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 16/65] x86/fpu: Use copy_xstate_to_uabi_buf() in xfpregs_get() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 17/65] x86/fpu: Use copy_xstate_to_uabi_buf() in fpregs_get() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 18/65] x86/fpu: Remove fpstate_sanitize_xstate() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 19/65] x86/fpu/regset: Move fpu__read_begin() into regset Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` Thomas Gleixner [this message]
2021-06-23 22:09 ` [tip: x86/fpu] x86/fpu: Move fpu__write_begin() to regset tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 21/65] x86/fpu: Get rid of using_compacted_format() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 22/65] x86/kvm: Avoid looking up PKRU in XSAVE buffer Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Dave Hansen
2021-06-23 12:01 ` [patch V4 23/65] x86/fpu: Cleanup arch_set_user_pkey_access() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 24/65] x86/fpu: Get rid of copy_supervisor_to_kernel() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 25/65] x86/fpu: Rename copy_xregs_to_kernel() and copy_kernel_to_xregs() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 26/65] x86/fpu: Rename copy_user_to_xregs() and copy_xregs_to_user() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 27/65] x86/fpu: Rename fxregs related copy functions Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] x86/fpu: Rename fxregs-related " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 28/65] x86/math-emu: Rename frstor() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 29/65] x86/fpu: Rename fregs related copy functions Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] x86/fpu: Rename fregs-related " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 30/65] x86/fpu: Rename xstate copy functions which are related to UABI Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 31/65] x86/fpu: Deduplicate copy_uabi_from_user/kernel_to_xstate() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:01 ` [patch V4 32/65] x86/fpu: Rename copy_fpregs_to_fpstate() to save_fpregs_to_fpstate() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 33/65] x86/fpu: Get rid of the FNSAVE optimization Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 34/65] x86/fpu: Rename copy_kernel_to_fpregs() to restore_fpregs_from_fpstate() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 35/65] x86/fpu: Rename initstate copy functions Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 36/65] x86/fpu: Rename "dynamic" XSTATEs to "independent" Thomas Gleixner
2021-06-23 12:02 ` [patch V4 37/65] x86/fpu/xstate: Sanitize handling of independent features Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 38/65] x86/pkeys: Move read_pkru() and write_pkru() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Dave Hansen
2021-06-23 12:02 ` [patch V4 39/65] x86/fpu: Rename and sanitize fpu__save/copy() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 40/65] x86/cpu: Sanitize X86_FEATURE_OSPKE Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 41/65] x86/pkru: Provide pkru_get_init_value() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 42/65] x86/pkru: Provide pkru_write_default() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 43/65] x86/cpu: Write the default PKRU value when enabling PKE Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 44/65] x86/fpu: Use pkru_write_default() in copy_init_fpstate_to_fpregs() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 45/65] x86/fpu: Rename fpu__clear_all() to fpu_flush_thread() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 46/65] x86/fpu: Clean up the fpu__clear() variants Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Andy Lutomirski
2021-06-23 12:02 ` [patch V4 47/65] x86/fpu: Rename __fpregs_load_activate() to fpregs_restore_userregs() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 48/65] x86/fpu: Move FXSAVE_LEAK quirk info __copy_kernel_to_fpregs() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 49/65] x86/fpu: Rename xfeatures_mask_user() to xfeatures_mask_uabi() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 50/65] x86/fpu: Dont restore PKRU in fpregs_restore_userspace() Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 51/65] x86/fpu: Add PKRU storage outside of task XSAVE buffer Thomas Gleixner
2021-06-23 22:09 ` [tip: x86/fpu] " tip-bot2 for Dave Hansen
2021-06-23 12:02 ` [patch V4 52/65] x86/fpu: Hook up PKRU into ptrace() Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Dave Hansen
2021-06-23 12:02 ` [patch V4 53/65] x86/fpu: Mask PKRU from kernel XRSTOR[S] operations Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 54/65] x86/fpu: Remove PKRU handling from switch_fpu_finish() Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 55/65] x86/fpu: Dont store PKRU in xstate in fpu_reset_fpstate() Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] x86/fpu: Don't " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 56/65] x86/pkru: Remove xstate fiddling from write_pkru() Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 57/65] x86/fpu: Mark init_fpstate __ro_after_init Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 58/65] x86/fpu/signal: Move initial checks into fpu__sig_restore() Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] x86/fpu/signal: Move initial checks into fpu__restore_sig() tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 59/65] x86/fpu/signal: Remove the legacy alignment check Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 60/65] x86/fpu/signal: Sanitize the xstate check on sigframe Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 61/65] x86/fpu/signal: Sanitize copy_user_to_fpregs_zeroing() Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 62/65] x86/fpu/signal: Split out the direct restore code Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 63/65] x86/fpu: Return proper error codes from user access functions Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 64/65] x86/fpu/signal: Handle #PF in the direct restore path Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-23 12:02 ` [patch V4 65/65] x86/fpu/signal: Let xrstor handle the features to init Thomas Gleixner
2021-06-23 22:08 ` [tip: x86/fpu] " tip-bot2 for Thomas Gleixner
2021-06-25 14:50 ` [patch V4 00/65] x86/fpu: Spring cleaning and PKRU sanitizing Oliver Sang
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