The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4c4a39dd5fe2d13e2d2fa5fceb8ef95d19fc389a Mon Sep 17 00:00:00 2001

From: Suzuki K Poulose suzuki.poulose@arm.com Date: Wed, 4 Jul 2018 23:07:45 +0100 Subject: [PATCH] arm64: Fix mismatched cache line size detection

If there is a mismatch in the I/D min line size, we must always use the system wide safe value both in applications and in the kernel, while performing cache operations. However, we have been checking more bits than just the min line sizes, which triggers false negatives. We may need to trap the user accesses in such cases, but not necessarily patch the kernel.

This patch fixes the check to do the right thing as advertised. A new capability will be added to check mismatches in other fields and ensure we trap the CTR accesses.

Fixes: be68a8aaf925 ("arm64: cpufeature: Fix CTR_EL0 field definitions") Cc: stable@vger.kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Reported-by: Will Deacon will.deacon@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Will Deacon will.deacon@arm.com

diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h index 5df5cfe1c143..5ee5bca8c24b 100644 --- a/arch/arm64/include/asm/cache.h +++ b/arch/arm64/include/asm/cache.h @@ -21,12 +21,16 @@ #define CTR_L1IP_SHIFT 14 #define CTR_L1IP_MASK 3 #define CTR_DMINLINE_SHIFT 16 +#define CTR_IMINLINE_SHIFT 0 #define CTR_ERG_SHIFT 20 #define CTR_CWG_SHIFT 24 #define CTR_CWG_MASK 15 #define CTR_IDC_SHIFT 28 #define CTR_DIC_SHIFT 29

+#define CTR_CACHE_MINLINE_MASK \ + (0xf << CTR_DMINLINE_SHIFT | 0xf << CTR_IMINLINE_SHIFT) + #define CTR_L1IP(ctr) (((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)

#define ICACHE_POLICY_VPIPT 0 diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 1d2b6d768efe..5d1fa928ea4b 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -68,9 +68,11 @@ static bool has_mismatched_cache_line_size(const struct arm64_cpu_capabilities *entry, int scope) { + u64 mask = CTR_CACHE_MINLINE_MASK; + WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); - return (read_cpuid_cachetype() & arm64_ftr_reg_ctrel0.strict_mask) != - (arm64_ftr_reg_ctrel0.sys_val & arm64_ftr_reg_ctrel0.strict_mask); + return (read_cpuid_cachetype() & mask) != + (arm64_ftr_reg_ctrel0.sys_val & mask); }

static void diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index f24892a40d2c..25d5cef00333 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -214,7 +214,7 @@ static const struct arm64_ftr_bits ftr_ctr[] = { * If we have differing I-cache policies, report it as the weakest - VIPT. */ ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_VIPT), /* L1Ip */ - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* IminLine */ + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0), ARM64_FTR_END, };