Thread (4 messages) flat view 4 messages, 3 authors, 2018-07-25

[PATCH] arm64: Check for errata before evaluating cpu features

From: suzuki.poulose@arm.com (Suzuki K Poulose)
Date: 2018-07-25 08:51:25
Also in: lkml

On 07/25/2018 09:35 AM, Dirk Mueller wrote:
Since commit d3aec8a28be3b8 ("arm64: capabilities: Restrict KPTI
detection to boot-time CPUs") we rely on errata flags being already
populated during feature enumeration. The order of errata and
features was flipped as part of commit ed478b3f9e4a ("arm64:
capabilities: Group handling of features and errata workarounds").

Return to the orginal order of errata and feature evaluation to
ensure errata flags are present during feature evaluation.

Fixes: d3aec8a28be3b8 ("arm64: capabilities: Restrict KPTI
detection to boot-time CPUs")
CC: Suzuki K Poulose <suzuki.poulose@arm.com>
CC: Marc Zyngier <redacted>
Signed-off-by: Dirk Mueller <redacted>
It would be good to add "Fixes: ed478b3f9e4a" (instead), just to make
sure this gets fixed everywhere the original problem appears.
quoted hunk ↗ jump to hunk
---
  arch/arm64/kernel/cpufeature.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index f24892a40d2c..c6d80743f4ed 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1351,9 +1351,9 @@ static void __update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
  
  static void update_cpu_capabilities(u16 scope_mask)
  {
-	__update_cpu_capabilities(arm64_features, scope_mask, "detected:");
  	__update_cpu_capabilities(arm64_errata, scope_mask,
  				  "enabling workaround for");
+	__update_cpu_capabilities(arm64_features, scope_mask, "detected:");
  }
  
  static int __enable_cpu_capability(void *arg)
@@ -1408,8 +1408,8 @@ __enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
  
  static void __init enable_cpu_capabilities(u16 scope_mask)
  {
-	__enable_cpu_capabilities(arm64_features, scope_mask);
  	__enable_cpu_capabilities(arm64_errata, scope_mask);
+	__enable_cpu_capabilities(arm64_features, scope_mask);
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
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