From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
linux-mm@kvack.org, linux-arch@vger.kernel.org,
linux-api@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Andy Lutomirski <luto@kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Borislav Petkov <bp@alien8.de>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Eugene Syromiatnikov <esyr@redhat.com>,
Florian Weimer <fweimer@redhat.com>,
"H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Kees Cook <keescook@chromium.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Nadav Amit <nadav.amit@gmail.com>,
Oleg Nesterov <oleg@redhat.com>, Pavel Machek <pavel@ucw.cz>,
Peter Zijlstra <peterz@infradead.org>,
Randy Dunlap <rdunlap@infradead.org>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>,
Dave Martin <Dave.Martin@arm.com>,
Weijiang Yang <weijiang.yang@intel.com>,
Pengfei Xu <pengfei.xu@intel.com>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v17 04/26] x86/cpufeatures: Introduce X86_FEATURE_CET and setup functions
Date: Tue, 29 Dec 2020 13:30:31 -0800 [thread overview]
Message-ID: <20201229213053.16395-5-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20201229213053.16395-1-yu-cheng.yu@intel.com>
Introduce a software-defined X86_FEATURE_CET, which indicates either Shadow
Stack or Indirect Branch Tracking (or both) is present. Also introduce
related cpu init/setup functions.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
arch/x86/include/asm/cpufeatures.h | 2 +-
arch/x86/include/asm/disabled-features.h | 5 ++-
arch/x86/include/uapi/asm/processor-flags.h | 2 ++
arch/x86/kernel/cpu/common.c | 40 ++++++++++++++++++++-
4 files changed, 46 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 292fe87b26b3..d1866659edbd 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -108,7 +108,7 @@
#define X86_FEATURE_EXTD_APICID ( 3*32+26) /* Extended APICID (8 bits) */
#define X86_FEATURE_AMD_DCM ( 3*32+27) /* AMD multi-node processor */
#define X86_FEATURE_APERFMPERF ( 3*32+28) /* P-State hardware coordination feedback capability (APERF/MPERF MSRs) */
-/* free ( 3*32+29) */
+#define X86_FEATURE_CET ( 3*32+29) /* Control-flow enforcement */
#define X86_FEATURE_NONSTOP_TSC_S3 ( 3*32+30) /* TSC doesn't stop in S3 state */
#define X86_FEATURE_TSC_KNOWN_FREQ ( 3*32+31) /* TSC has known frequency */
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 4d3b7ce509e5..86ac4a1c6d81 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -71,9 +71,11 @@
#ifdef CONFIG_X86_CET_USER
#define DISABLE_SHSTK 0
#define DISABLE_IBT 0
+#define DISABLE_CET 0
#else
#define DISABLE_SHSTK (1 << (X86_FEATURE_SHSTK & 31))
#define DISABLE_IBT (1 << (X86_FEATURE_IBT & 31))
+#define DISABLE_CET (1 << (X86_FEATURE_CET & 31))
#endif
/*
@@ -82,7 +84,8 @@
#define DISABLED_MASK0 (DISABLE_VME)
#define DISABLED_MASK1 0
#define DISABLED_MASK2 0
-#define DISABLED_MASK3 (DISABLE_CYRIX_ARR|DISABLE_CENTAUR_MCR|DISABLE_K6_MTRR)
+#define DISABLED_MASK3 (DISABLE_CYRIX_ARR|DISABLE_CENTAUR_MCR|DISABLE_K6_MTRR| \
+ DISABLE_CET)
#define DISABLED_MASK4 (DISABLE_PCID)
#define DISABLED_MASK5 0
#define DISABLED_MASK6 0
diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h
index bcba3c643e63..a8df907e8017 100644
--- a/arch/x86/include/uapi/asm/processor-flags.h
+++ b/arch/x86/include/uapi/asm/processor-flags.h
@@ -130,6 +130,8 @@
#define X86_CR4_SMAP _BITUL(X86_CR4_SMAP_BIT)
#define X86_CR4_PKE_BIT 22 /* enable Protection Keys support */
#define X86_CR4_PKE _BITUL(X86_CR4_PKE_BIT)
+#define X86_CR4_CET_BIT 23 /* enable Control-flow Enforcement */
+#define X86_CR4_CET _BITUL(X86_CR4_CET_BIT)
/*
* x86-64 Task Priority Register, CR8
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 35ad8480c464..03c367f79adc 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -510,6 +510,14 @@ static __init int setup_disable_pku(char *arg)
__setup("nopku", setup_disable_pku);
#endif /* CONFIG_X86_64 */
+static __always_inline void setup_cet(struct cpuinfo_x86 *c)
+{
+ if (!cpu_feature_enabled(X86_FEATURE_CET))
+ return;
+
+ cr4_set_bits(X86_CR4_CET);
+}
+
/*
* Some CPU features depend on higher CPUID levels, which may not always
* be available due to CPUID level capping or broken virtualization
@@ -895,6 +903,12 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
}
}
+static void init_cet_features(struct cpuinfo_x86 *c)
+{
+ if (cpu_has(c, X86_FEATURE_SHSTK) || cpu_has(c, X86_FEATURE_IBT))
+ set_cpu_cap(c, X86_FEATURE_CET);
+}
+
void get_cpu_cap(struct cpuinfo_x86 *c)
{
u32 eax, ebx, ecx, edx;
@@ -960,6 +974,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
if (c->extended_cpuid_level >= 0x8000000a)
c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
+ init_cet_features(c);
init_scattered_cpuid_features(c);
init_speculation_control(c);
@@ -1221,6 +1236,15 @@ static void detect_nopl(void)
#endif
}
+static void adjust_combined_cpu_features(void)
+{
+#ifdef CONFIG_X86_CET_USER
+ if (test_bit(X86_FEATURE_SHSTK, (unsigned long *)cpu_caps_cleared) &&
+ test_bit(X86_FEATURE_IBT, (unsigned long *)cpu_caps_cleared))
+ setup_clear_cpu_cap(X86_FEATURE_CET);
+#endif
+}
+
/*
* We parse cpu parameters early because fpu__init_system() is executed
* before parse_early_param().
@@ -1252,9 +1276,19 @@ static void __init cpu_parse_early_param(void)
if (cmdline_find_option_bool(boot_command_line, "noxsaves"))
setup_clear_cpu_cap(X86_FEATURE_XSAVES);
+ /*
+ * CET states are XSAVES states and options must be parsed early.
+ */
+#ifdef CONFIG_X86_CET_USER
+ if (cmdline_find_option_bool(boot_command_line, "no_user_shstk"))
+ setup_clear_cpu_cap(X86_FEATURE_SHSTK);
+ if (cmdline_find_option_bool(boot_command_line, "no_user_ibt"))
+ setup_clear_cpu_cap(X86_FEATURE_IBT);
+#endif
+
arglen = cmdline_find_option(boot_command_line, "clearcpuid", arg, sizeof(arg));
if (arglen <= 0)
- return;
+ goto done;
pr_info("Clearing CPUID bits:");
do {
@@ -1272,6 +1306,9 @@ static void __init cpu_parse_early_param(void)
}
} while (res == 2);
pr_cont("\n");
+
+done:
+ adjust_combined_cpu_features();
}
/*
@@ -1591,6 +1628,7 @@ static void identify_cpu(struct cpuinfo_x86 *c)
x86_init_rdrand(c);
setup_pku(c);
+ setup_cet(c);
/*
* Clear/Set all flags overridden by options, need do it
--
2.21.0
next prev parent reply other threads:[~2020-12-29 21:33 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-29 21:30 [PATCH v17 00/26] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 01/26] Documentation/x86: Add CET description Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 02/26] x86/cet/shstk: Add Kconfig option for user-mode control-flow protection Yu-cheng Yu
2021-01-19 11:06 ` Borislav Petkov
2021-01-19 18:10 ` Yu, Yu-cheng
2020-12-29 21:30 ` [PATCH v17 03/26] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2020-12-29 21:30 ` Yu-cheng Yu [this message]
2021-01-11 17:56 ` [PATCH v17 04/26] x86/cpufeatures: Introduce X86_FEATURE_CET and setup functions Borislav Petkov
2021-01-11 20:25 ` Yu, Yu-cheng
2021-01-11 23:09 ` Yu-cheng Yu
2021-01-12 0:09 ` Yu, Yu-cheng
2021-01-12 12:38 ` Borislav Petkov
2021-01-12 23:02 ` Yu, Yu-cheng
2021-01-13 10:04 ` Borislav Petkov
2020-12-29 21:30 ` [PATCH v17 05/26] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 06/26] x86/cet: Add control-protection fault handler Yu-cheng Yu
2021-01-19 12:04 ` Borislav Petkov
2021-01-19 19:36 ` Yu, Yu-cheng
2020-12-29 21:30 ` [PATCH v17 07/26] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 08/26] x86/mm: Introduce _PAGE_COW Yu-cheng Yu
2021-01-21 18:44 ` Borislav Petkov
2021-01-21 20:16 ` Yu, Yu-cheng
2021-01-21 20:20 ` Dave Hansen
2021-01-21 20:26 ` Dave Hansen
2021-01-21 20:44 ` Yu, Yu-cheng
2021-01-21 20:41 ` Borislav Petkov
2021-01-21 21:40 ` Yu, Yu-cheng
2021-01-21 22:16 ` David Laight
2021-01-21 22:19 ` Randy Dunlap
2021-01-21 22:32 ` David Laight
2021-01-22 21:54 ` Yu, Yu-cheng
2020-12-29 21:30 ` [PATCH v17 09/26] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 10/26] x86/mm: Update pte_modify for _PAGE_COW Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 11/26] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY to _PAGE_COW Yu-cheng Yu
2021-01-25 18:27 ` Borislav Petkov
2021-01-25 21:27 ` Yu, Yu-cheng
2021-01-25 21:55 ` Borislav Petkov
2021-01-25 22:18 ` Yu, Yu-cheng
2021-01-26 10:24 ` Borislav Petkov
2021-01-26 16:45 ` Yu, Yu-cheng
2021-01-26 8:46 ` Peter Zijlstra
2021-01-26 9:40 ` Peter Zijlstra
2021-01-26 16:43 ` Yu, Yu-cheng
2020-12-29 21:30 ` [PATCH v17 12/26] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 13/26] x86/mm: Shadow Stack page fault error checking Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 14/26] x86/mm: Update maybe_mkwrite() for shadow stack Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 15/26] mm: Fixup places that call pte_mkwrite() directly Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 16/26] mm: Add guard pages around a shadow stack Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 17/26] mm/mmap: Add shadow stack pages to memory accounting Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 18/26] mm: Update can_follow_write_pte() for shadow stack Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 19/26] mm: Re-introduce vm_flags to do_mmap() Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 20/26] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 21/26] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 22/26] binfmt_elf: Define GNU_PROPERTY_X86_FEATURE_1_AND properties Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 23/26] ELF: Introduce arch_setup_elf_property() Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 24/26] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 25/26] x86/cet/shstk: Add arch_prctl functions for " Yu-cheng Yu
2020-12-29 21:30 ` [PATCH v17 26/26] mm: Introduce PROT_SHSTK " Yu-cheng Yu
2021-01-04 20:08 ` [PATCH v17 00/26] Control-flow Enforcement: Shadow Stack Yu, Yu-cheng
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