diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2019-04-03 18:41:56 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2019-04-12 20:21:10 +0200 |
| commit | a5eff7259790d5314eff10563d6e59d358cce482 (patch) | |
| tree | 8da9f41dc68288afc7698f38e2908136fccae9c0 | |
| parent | 06b251dff78704c7d122bd109384d970a7dbe94d (diff) | |
| download | linux-a5eff7259790d5314eff10563d6e59d358cce482.tar.bz2 | |
x86/pkeys: Add PKRU value to init_fpstate
The task's initial PKRU value is set partly for fpu__clear()/
copy_init_pkru_to_fpregs(). It is not part of init_fpstate.xsave and
instead it is set explicitly.
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 copy_init_pkru_to_fpregs() could be removed because restoring
the PKRU at return-to-userland should be enough.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-28-bigeasy@linutronix.de
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 5 | ||||
| -rw-r--r-- | arch/x86/mm/pkeys.c | 6 |
2 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index cb28e98a0659..352fa19e6311 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 2ecbf4155f98..1dcfc91c8f0c 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; } |