[v8,08/10] arm64: Always enable ssb vulnerability detection

Message ID	20190415212129.1112-9-jeremy.linton@arm.com
State	New
Headers	show Delivered-To: patch@linaro.org Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; From: Jeremy Linton <jeremy.linton@arm.com> To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com, suzuki.poulose@arm.com, Dave.Martin@arm.com, shankerd@codeaurora.org, julien.thierry@arm.com, mlangsdo@redhat.com, stefan.wahren@i2se.com, Andre.Przywara@arm.com, linux-kernel@vger.kernel.org, Jeremy Linton <jeremy.linton@arm.com>, Andre Przywara <andre.przywara@arm.com> Subject: [v8 08/10] arm64: Always enable ssb vulnerability detection Date: Mon, 15 Apr 2019 16:21:27 -0500 Message-Id: <20190415212129.1112-9-jeremy.linton@arm.com> In-Reply-To: <20190415212129.1112-1-jeremy.linton@arm.com> References: <20190415212129.1112-1-jeremy.linton@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk
Series	arm64: add system vulnerability sysfs entries \| expand [v8,00/10] arm64: add system vulnerability sysfs entries [v8,01/10] arm64: Provide a command line to disable spectre_v2 mitigation [v8,02/10] arm64: add sysfs vulnerability show for spectre v1 [v8,03/10] arm64: add sysfs vulnerability show for meltdown [v8,04/10] arm64: Advertise mitigation of Spectre-v2, or lack thereof [v8,05/10] arm64: Use firmware to detect CPUs that are not affected by Spectre-v2 [v8,06/10] arm64: Always enable spectrev2 vulnerability detection [v8,07/10] arm64: add sysfs vulnerability show for spectre v2 [v8,08/10] arm64: Always enable ssb vulnerability detection [v8,09/10] arm64: add sysfs vulnerability show for speculative store bypass [v8,10/10] arm64: enable generic CPU vulnerabilites support

Message ID

20190415212129.1112-9-jeremy.linton@arm.com

State

New

Headers

Received-SPF: pass (google.com: best guess record for domain of
	linux-kernel-owner@vger.kernel.org designates 209.132.180.67
	as permitted sender) client-ip=209.132.180.67; 
From: Jeremy Linton <jeremy.linton@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com,
	suzuki.poulose@arm.com, Dave.Martin@arm.com,
	shankerd@codeaurora.org, julien.thierry@arm.com,
	mlangsdo@redhat.com, stefan.wahren@i2se.com,
	Andre.Przywara@arm.com, linux-kernel@vger.kernel.org,
	Jeremy Linton <jeremy.linton@arm.com>,
	Andre Przywara <andre.przywara@arm.com>
Subject: [v8 08/10] arm64: Always enable ssb vulnerability detection
Date: Mon, 15 Apr 2019 16:21:27 -0500
Message-Id: <20190415212129.1112-9-jeremy.linton@arm.com>
In-Reply-To: <20190415212129.1112-1-jeremy.linton@arm.com>
References: <20190415212129.1112-1-jeremy.linton@arm.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Series

arm64: add system vulnerability sysfs entries | expand

Commit Message

Jeremy Linton April 15, 2019, 9:21 p.m. UTC

The ssb detection logic is necessary regardless of whether
the vulnerability mitigation code is built into the kernel.
Break it out so that the CONFIG option only controls the
mitigation logic and not the vulnerability detection.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

Tested-by: Stefan Wahren <stefan.wahren@i2se.com>

---
 arch/arm64/include/asm/cpufeature.h |  4 ----
 arch/arm64/kernel/cpu_errata.c      | 11 +++++++----
 2 files changed, 7 insertions(+), 8 deletions(-)

-- 
2.20.1

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index e505e1fbd2b9..6ccdc97e5d6a 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -638,11 +638,7 @@  static inline int arm64_get_ssbd_state(void)
 #endif
 }
 
-#ifdef CONFIG_ARM64_SSBD
 void arm64_set_ssbd_mitigation(bool state);
-#else
-static inline void arm64_set_ssbd_mitigation(bool state) {}
-#endif
 
 extern int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt);
 
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index e51ddcb197c0..5814645afd73 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -275,7 +275,6 @@  static int detect_harden_bp_fw(void)
 	return 1;
 }
 
-#ifdef CONFIG_ARM64_SSBD
 DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
 
 int ssbd_state __read_mostly = ARM64_SSBD_KERNEL;
@@ -346,6 +345,7 @@  void __init arm64_enable_wa2_handling(struct alt_instr *alt,
 		*updptr = cpu_to_le32(aarch64_insn_gen_nop());
 }
 
+#ifdef CONFIG_ARM64_SSBD
 void arm64_set_ssbd_mitigation(bool state)
 {
 	if (this_cpu_has_cap(ARM64_SSBS)) {
@@ -370,6 +370,12 @@  void arm64_set_ssbd_mitigation(bool state)
 		break;
 	}
 }
+#else
+void arm64_set_ssbd_mitigation(bool state)
+{
+	pr_info_once("SSBD disabled by kernel configuration\n");
+}
+#endif	/* CONFIG_ARM64_SSBD */
 
 static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
 				    int scope)
@@ -467,7 +473,6 @@  static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
 
 	return required;
 }
-#endif	/* CONFIG_ARM64_SSBD */
 
 static void __maybe_unused
 cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused)
@@ -759,14 +764,12 @@  const struct arm64_cpu_capabilities arm64_errata[] = {
 		ERRATA_MIDR_RANGE_LIST(arm64_harden_el2_vectors),
 	},
 #endif
-#ifdef CONFIG_ARM64_SSBD
 	{
 		.desc = "Speculative Store Bypass Disable",
 		.capability = ARM64_SSBD,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
 		.matches = has_ssbd_mitigation,
 	},
-#endif
 #ifdef CONFIG_ARM64_ERRATUM_1188873
 	{
 		/* Cortex-A76 r0p0 to r2p0 */

[v8,08/10] arm64: Always enable ssb vulnerability detection

Commit Message

Patch