From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, "Andy Lutomirski" <luto@kernel.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
kvm@vger.kernel.org, "Jason A. Donenfeld" <Jason@zx2c4.com>,
"Rik van Riel" <riel@surriel.com>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>
Subject: [PATCH 27/27] x86/pkeys: add PKRU value to init_fpstate
Date: Wed, 3 Apr 2019 18:41:56 +0200 [thread overview]
Message-ID: <20190403164156.19645-28-bigeasy@linutronix.de> (raw)
In-Reply-To: <20190403164156.19645-1-bigeasy@linutronix.de>
The task's initiall PKRU value is set part for fpu__clear()/
copy_init_pkru_to_fpregs(). It is not part of init_fpstate.xsave and
instead it is set explictly.
If the user removes the PKRU state from XSAVE in the signal handler then
__fpu__restore_sig() will restore the missing bits from `init_fpstate'
and initialize the PKRU value to 0.
Add the `init_pkru_value' to `init_fpstate' so it is set to the init
value in such a case.
In theory we could drop copy_init_pkru_to_fpregs() because restoring the
PKRU at return-to-userland should be enough.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
arch/x86/kernel/cpu/common.c | 5 +++++
arch/x86/mm/pkeys.c | 6 ++++++
2 files changed, 11 insertions(+)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index cb28e98a0659a..352fa19e63110 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -372,6 +372,8 @@ static bool pku_disabled;
static __always_inline void setup_pku(struct cpuinfo_x86 *c)
{
+ struct pkru_state *pk;
+
/* check the boot processor, plus compile options for PKU: */
if (!cpu_feature_enabled(X86_FEATURE_PKU))
return;
@@ -382,6 +384,9 @@ static __always_inline void setup_pku(struct cpuinfo_x86 *c)
return;
cr4_set_bits(X86_CR4_PKE);
+ pk = get_xsave_addr(&init_fpstate.xsave, XFEATURE_PKRU);
+ if (pk)
+ pk->pkru = init_pkru_value;
/*
* Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE
* cpuid bit to be set. We need to ensure that we
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index 2ecbf4155f98f..1dcfc91c8f0c3 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -18,6 +18,7 @@
#include <asm/cpufeature.h> /* boot_cpu_has, ... */
#include <asm/mmu_context.h> /* vma_pkey() */
+#include <asm/fpu/internal.h> /* init_fpstate */
int __execute_only_pkey(struct mm_struct *mm)
{
@@ -161,6 +162,7 @@ static ssize_t init_pkru_read_file(struct file *file, char __user *user_buf,
static ssize_t init_pkru_write_file(struct file *file,
const char __user *user_buf, size_t count, loff_t *ppos)
{
+ struct pkru_state *pk;
char buf[32];
ssize_t len;
u32 new_init_pkru;
@@ -183,6 +185,10 @@ static ssize_t init_pkru_write_file(struct file *file,
return -EINVAL;
WRITE_ONCE(init_pkru_value, new_init_pkru);
+ pk = get_xsave_addr(&init_fpstate.xsave, XFEATURE_PKRU);
+ if (!pk)
+ return -EINVAL;
+ pk->pkru = new_init_pkru;
return count;
}
--
2.20.1
next prev parent reply other threads:[~2019-04-03 16:41 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-03 16:41 [PATCH v9 00/27] x86: load FPU registers on return to userland Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 01/27] x86/fpu: Remove fpu->initialized usage in __fpu__restore_sig() Sebastian Andrzej Siewior
2019-04-13 20:46 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 02/27] x86/fpu: Remove fpu__restore() Sebastian Andrzej Siewior
2019-04-13 20:47 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 03/27] x86/fpu: Remove preempt_disable() in fpu__clear() Sebastian Andrzej Siewior
2019-04-13 20:48 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 04/27] x86/fpu: Always init the `state' " Sebastian Andrzej Siewior
2019-04-13 20:48 ` [tip:x86/fpu] x86/fpu: Always init the state " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 05/27] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe() Sebastian Andrzej Siewior
2019-04-13 20:49 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 06/27] x86/fpu: Don't save fxregs for ia32 frames " Sebastian Andrzej Siewior
2019-04-13 20:50 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 07/27] x86/fpu: Remove fpu->initialized Sebastian Andrzej Siewior
2019-04-13 20:50 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 08/27] x86/fpu: Remove user_fpu_begin() Sebastian Andrzej Siewior
2019-04-13 20:51 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 09/27] x86/fpu: Add (__)make_fpregs_active helpers Sebastian Andrzej Siewior
2019-04-13 20:52 ` [tip:x86/fpu] x86/fpu: Add an __fpregs_load_activate() internal helper tip-bot for Rik van Riel
2019-04-03 16:41 ` [PATCH 10/27] x86/fpu: Make __raw_xsave_addr() use feature number instead of mask Sebastian Andrzej Siewior
2019-04-13 20:52 ` [tip:x86/fpu] x86/fpu: Make __raw_xsave_addr() use a " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 11/27] x86/fpu: Make get_xsave_field_ptr() and get_xsave_addr() use " Sebastian Andrzej Siewior
2019-04-13 20:53 ` [tip:x86/fpu] x86/fpu: Use a feature number instead of mask in two more helpers tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 12/27] x86/pkru: Provide .*_pkru_ins() functions Sebastian Andrzej Siewior
2019-04-10 16:36 ` Borislav Petkov
2019-04-10 16:52 ` Borislav Petkov
2019-04-10 21:25 ` Sebastian Andrzej Siewior
2019-04-10 21:29 ` Dave Hansen
2019-04-11 13:24 ` Borislav Petkov
2019-04-13 20:54 ` [tip:x86/fpu] x86/pkeys: Provide *pkru() helpers tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 13/27] x86/fpu: Only write PKRU if it is different from current Sebastian Andrzej Siewior
2019-04-13 20:55 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 14/27] x86/pkeys: Don't check if PKRU is zero before writting it Sebastian Andrzej Siewior
2019-04-13 20:55 ` [tip:x86/fpu] x86/pkeys: Don't check if PKRU is zero before writing it tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 15/27] x86/fpu: Eager switch PKRU state Sebastian Andrzej Siewior
2019-04-13 20:56 ` [tip:x86/fpu] " tip-bot for Rik van Riel
2019-04-03 16:41 ` [PATCH 16/27] x86/entry: Add TIF_NEED_FPU_LOAD Sebastian Andrzej Siewior
2019-04-13 20:57 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 17/27] x86/fpu: Always store the registers in copy_fpstate_to_sigframe() Sebastian Andrzej Siewior
2019-04-13 20:57 ` [tip:x86/fpu] " tip-bot for Rik van Riel
2019-04-03 16:41 ` [PATCH 18/27] x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD Sebastian Andrzej Siewior
2019-04-13 20:58 ` [tip:x86/fpu] " tip-bot for Rik van Riel
2019-04-03 16:41 ` [PATCH 19/27] x86/fpu: Update xstate's PKRU value on write_pkru() Sebastian Andrzej Siewior
2019-04-08 18:14 ` Dave Hansen
2019-04-08 20:03 ` Sebastian Andrzej Siewior
2019-04-13 20:59 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 20/27] x86/fpu: Inline copy_user_to_fpregs_zeroing() Sebastian Andrzej Siewior
2019-04-13 21:00 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 21/27] x86/fpu: Let __fpu__restore_sig() restore the !32bit+fxsr frame from kernel memory Sebastian Andrzej Siewior
2019-04-13 21:00 ` [tip:x86/fpu] x86/fpu: Restore from kernel memory on the 64-bit path too tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 22/27] x86/fpu: Merge the two code paths in __fpu__restore_sig() Sebastian Andrzej Siewior
2019-04-13 21:01 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 23/27] x86/fpu: Defer FPU state load until return to userspace Sebastian Andrzej Siewior
2019-04-12 14:36 ` Borislav Petkov
2019-04-12 15:24 ` Sebastian Andrzej Siewior
2019-04-12 16:22 ` Borislav Petkov
2019-04-12 16:37 ` Sebastian Andrzej Siewior
2019-04-12 16:48 ` Borislav Petkov
2019-04-12 17:19 ` Sebastian Andrzej Siewior
2019-04-12 17:29 ` Borislav Petkov
2019-04-15 9:14 ` Sebastian Andrzej Siewior
2019-04-13 21:02 ` [tip:x86/fpu] " tip-bot for Rik van Riel
2019-04-03 16:41 ` [PATCH 24/27] x86/fpu: Add a fastpath to __fpu__restore_sig() Sebastian Andrzej Siewior
2019-04-08 17:05 ` Thomas Gleixner
2019-04-08 20:02 ` Sebastian Andrzej Siewior
2019-04-09 7:27 ` Thomas Gleixner
2019-04-12 17:17 ` Borislav Petkov
2019-04-12 17:27 ` Sebastian Andrzej Siewior
2019-04-13 21:02 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 25/27] x86/fpu: Add a fastpath to copy_fpstate_to_sigframe() Sebastian Andrzej Siewior
2019-04-13 21:03 ` [tip:x86/fpu] " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` [PATCH 26/27] x86/fpu: Restore FPU register in copy_fpstate_to_sigframe() in order to use the fastpath Sebastian Andrzej Siewior
2019-04-13 21:04 ` [tip:x86/fpu] x86/fpu: Restore regs " tip-bot for Sebastian Andrzej Siewior
2019-04-03 16:41 ` Sebastian Andrzej Siewior [this message]
2019-04-13 21:05 ` [tip:x86/fpu] x86/pkeys: Add PKRU value to init_fpstate tip-bot for Sebastian Andrzej Siewior
2019-04-04 14:01 ` [PATCH v9 00/27] x86: load FPU registers on return to userland David Laight
2019-04-04 14:14 ` 'Sebastian Andrzej Siewior'
2019-04-04 14:26 ` Andy Lutomirski
2019-04-04 14:31 ` Sebastian Andrzej Siewior
2019-04-04 15:10 ` David Laight
2019-04-08 17:08 ` Thomas Gleixner
2019-04-12 18:30 ` Borislav Petkov
2019-04-15 8:58 ` Sebastian Andrzej Siewior
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