This is a note to let you know that I've just added the patch titled
x86/pkeys: Revert a5eff7259790 ("x86/pkeys: Add PKRU value to init_fpstate")
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-pkeys-revert-a5eff7259790-x86-pkeys-add-pkru-value-to-init_fpstate.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b3607269ff57fd3c9690cb25962c5e4b91a0fd3b Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Wed, 23 Jun 2021 14:01:29 +0200
Subject: x86/pkeys: Revert a5eff7259790 ("x86/pkeys: Add PKRU value to init_fpstate")
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
commit b3607269ff57fd3c9690cb25962c5e4b91a0fd3b upstream.
This cannot work and it's unclear how that ever made a difference.
init_fpstate.xsave.header.xfeatures is always 0 so get_xsave_addr() will
always return a NULL pointer, which will prevent storing the default PKRU
value in init_fpstate.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lkml.kernel.org/r/20210623121451.451391598@xxxxxxxxxxxxx
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/common.c | 5 -----
arch/x86/mm/pkeys.c | 6 ------
2 files changed, 11 deletions(-)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -450,8 +450,6 @@ 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;
@@ -462,9 +460,6 @@ static __always_inline void setup_pku(st
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
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -10,7 +10,6 @@
#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)
{
@@ -154,7 +153,6 @@ static ssize_t init_pkru_read_file(struc
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;
@@ -177,10 +175,6 @@ static ssize_t init_pkru_write_file(stru
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;
}
Patches currently in stable-queue which might be from tglx@xxxxxxxxxxxxx are
queue-5.4/x86-pkeys-revert-a5eff7259790-x86-pkeys-add-pkru-value-to-init_fpstate.patch
