Commit 4e56de82 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Will Deacon
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arm64/cpuinfo: Define HWCAP name arrays per their actual bit definitions 



HWCAP name arrays (hwcap_str, compat_hwcap_str, compat_hwcap2_str) that are
scanned for /proc/cpuinfo are detached from their bit definitions making it
vulnerable and difficult to correlate. It is also bit problematic because
during /proc/cpuinfo dump these arrays get traversed sequentially assuming
they reflect and match actual HWCAP bit sequence, to test various features
for a given CPU. This redefines name arrays per their HWCAP bit definitions
. It also warns after detecting any feature which is not expected on arm64.

Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/1599630535-29337-1-git-send-email-anshuman.khandual@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent f75aef39

arch/arm64/include/asm/hwcap.h

+9 −0
Original line number Diff line number Diff line
@@ -8,18 +8,27 @@ 
#include <uapi/asm/hwcap.h>

#include <asm/cpufeature.h>



#define COMPAT_HWCAP_SWP	(1 << 0)

#define COMPAT_HWCAP_HALF	(1 << 1)

#define COMPAT_HWCAP_THUMB	(1 << 2)

#define COMPAT_HWCAP_26BIT	(1 << 3)

#define COMPAT_HWCAP_FAST_MULT	(1 << 4)

#define COMPAT_HWCAP_FPA	(1 << 5)

#define COMPAT_HWCAP_VFP	(1 << 6)

#define COMPAT_HWCAP_EDSP	(1 << 7)

#define COMPAT_HWCAP_JAVA	(1 << 8)

#define COMPAT_HWCAP_IWMMXT	(1 << 9)

#define COMPAT_HWCAP_CRUNCH	(1 << 10)

#define COMPAT_HWCAP_THUMBEE	(1 << 11)

#define COMPAT_HWCAP_NEON	(1 << 12)

#define COMPAT_HWCAP_VFPv3	(1 << 13)

#define COMPAT_HWCAP_VFPV3D16	(1 << 14)

#define COMPAT_HWCAP_TLS	(1 << 15)

#define COMPAT_HWCAP_VFPv4	(1 << 16)

#define COMPAT_HWCAP_IDIVA	(1 << 17)

#define COMPAT_HWCAP_IDIVT	(1 << 18)

#define COMPAT_HWCAP_IDIV	(COMPAT_HWCAP_IDIVA|COMPAT_HWCAP_IDIVT)

#define COMPAT_HWCAP_VFPD32	(1 << 19)

#define COMPAT_HWCAP_LPAE	(1 << 20)

#define COMPAT_HWCAP_EVTSTRM	(1 << 21)

arch/arm64/kernel/cpuinfo.c

+92 −85
Original line number Diff line number Diff line
@@ -43,94 +43,92 @@ static const char *icache_policy_str[] = { 
unsigned long __icache_flags;



static const char *const hwcap_str[] = {

	"fp",

	"asimd",

	"evtstrm",

	"aes",

	"pmull",

	"sha1",

	"sha2",

	"crc32",

	"atomics",

	"fphp",

	"asimdhp",

	"cpuid",

	"asimdrdm",

	"jscvt",

	"fcma",

	"lrcpc",

	"dcpop",

	"sha3",

	"sm3",

	"sm4",

	"asimddp",

	"sha512",

	"sve",

	"asimdfhm",

	"dit",

	"uscat",

	"ilrcpc",

	"flagm",

	"ssbs",

	"sb",

	"paca",

	"pacg",

	"dcpodp",

	"sve2",

	"sveaes",

	"svepmull",

	"svebitperm",

	"svesha3",

	"svesm4",

	"flagm2",

	"frint",

	"svei8mm",

	"svef32mm",

	"svef64mm",

	"svebf16",

	"i8mm",

	"bf16",

	"dgh",

	"rng",

	"bti",

	/* reserved for "mte" */

	NULL

	[KERNEL_HWCAP_FP]		= "fp",

	[KERNEL_HWCAP_ASIMD]		= "asimd",

	[KERNEL_HWCAP_EVTSTRM]		= "evtstrm",

	[KERNEL_HWCAP_AES]		= "aes",

	[KERNEL_HWCAP_PMULL]		= "pmull",

	[KERNEL_HWCAP_SHA1]		= "sha1",

	[KERNEL_HWCAP_SHA2]		= "sha2",

	[KERNEL_HWCAP_CRC32]		= "crc32",

	[KERNEL_HWCAP_ATOMICS]		= "atomics",

	[KERNEL_HWCAP_FPHP]		= "fphp",

	[KERNEL_HWCAP_ASIMDHP]		= "asimdhp",

	[KERNEL_HWCAP_CPUID]		= "cpuid",

	[KERNEL_HWCAP_ASIMDRDM]		= "asimdrdm",

	[KERNEL_HWCAP_JSCVT]		= "jscvt",

	[KERNEL_HWCAP_FCMA]		= "fcma",

	[KERNEL_HWCAP_LRCPC]		= "lrcpc",

	[KERNEL_HWCAP_DCPOP]		= "dcpop",

	[KERNEL_HWCAP_SHA3]		= "sha3",

	[KERNEL_HWCAP_SM3]		= "sm3",

	[KERNEL_HWCAP_SM4]		= "sm4",

	[KERNEL_HWCAP_ASIMDDP]		= "asimddp",

	[KERNEL_HWCAP_SHA512]		= "sha512",

	[KERNEL_HWCAP_SVE]		= "sve",

	[KERNEL_HWCAP_ASIMDFHM]		= "asimdfhm",

	[KERNEL_HWCAP_DIT]		= "dit",

	[KERNEL_HWCAP_USCAT]		= "uscat",

	[KERNEL_HWCAP_ILRCPC]		= "ilrcpc",

	[KERNEL_HWCAP_FLAGM]		= "flagm",

	[KERNEL_HWCAP_SSBS]		= "ssbs",

	[KERNEL_HWCAP_SB]		= "sb",

	[KERNEL_HWCAP_PACA]		= "paca",

	[KERNEL_HWCAP_PACG]		= "pacg",

	[KERNEL_HWCAP_DCPODP]		= "dcpodp",

	[KERNEL_HWCAP_SVE2]		= "sve2",

	[KERNEL_HWCAP_SVEAES]		= "sveaes",

	[KERNEL_HWCAP_SVEPMULL]		= "svepmull",

	[KERNEL_HWCAP_SVEBITPERM]	= "svebitperm",

	[KERNEL_HWCAP_SVESHA3]		= "svesha3",

	[KERNEL_HWCAP_SVESM4]		= "svesm4",

	[KERNEL_HWCAP_FLAGM2]		= "flagm2",

	[KERNEL_HWCAP_FRINT]		= "frint",

	[KERNEL_HWCAP_SVEI8MM]		= "svei8mm",

	[KERNEL_HWCAP_SVEF32MM]		= "svef32mm",

	[KERNEL_HWCAP_SVEF64MM]		= "svef64mm",

	[KERNEL_HWCAP_SVEBF16]		= "svebf16",

	[KERNEL_HWCAP_I8MM]		= "i8mm",

	[KERNEL_HWCAP_BF16]		= "bf16",

	[KERNEL_HWCAP_DGH]		= "dgh",

	[KERNEL_HWCAP_RNG]		= "rng",

	[KERNEL_HWCAP_BTI]		= "bti",

};



#ifdef CONFIG_COMPAT

#define COMPAT_KERNEL_HWCAP(x)	const_ilog2(COMPAT_HWCAP_ ## x)

static const char *const compat_hwcap_str[] = {

	"swp",

	"half",

	"thumb",

	"26bit",

	"fastmult",

	"fpa",

	"vfp",

	"edsp",

	"java",

	"iwmmxt",

	"crunch",

	"thumbee",

	"neon",

	"vfpv3",

	"vfpv3d16",

	"tls",

	"vfpv4",

	"idiva",

	"idivt",

	"vfpd32",

	"lpae",

	"evtstrm",

	NULL

	[COMPAT_KERNEL_HWCAP(SWP)]	= "swp",

	[COMPAT_KERNEL_HWCAP(HALF)]	= "half",

	[COMPAT_KERNEL_HWCAP(THUMB)]	= "thumb",

	[COMPAT_KERNEL_HWCAP(26BIT)]	= NULL,	/* Not possible on arm64 */

	[COMPAT_KERNEL_HWCAP(FAST_MULT)] = "fastmult",

	[COMPAT_KERNEL_HWCAP(FPA)]	= NULL,	/* Not possible on arm64 */

	[COMPAT_KERNEL_HWCAP(VFP)]	= "vfp",

	[COMPAT_KERNEL_HWCAP(EDSP)]	= "edsp",

	[COMPAT_KERNEL_HWCAP(JAVA)]	= NULL,	/* Not possible on arm64 */

	[COMPAT_KERNEL_HWCAP(IWMMXT)]	= NULL,	/* Not possible on arm64 */

	[COMPAT_KERNEL_HWCAP(CRUNCH)]	= NULL,	/* Not possible on arm64 */

	[COMPAT_KERNEL_HWCAP(THUMBEE)]	= NULL,	/* Not possible on arm64 */

	[COMPAT_KERNEL_HWCAP(NEON)]	= "neon",

	[COMPAT_KERNEL_HWCAP(VFPv3)]	= "vfpv3",

	[COMPAT_KERNEL_HWCAP(VFPV3D16)]	= NULL,	/* Not possible on arm64 */

	[COMPAT_KERNEL_HWCAP(TLS)]	= "tls",

	[COMPAT_KERNEL_HWCAP(VFPv4)]	= "vfpv4",

	[COMPAT_KERNEL_HWCAP(IDIVA)]	= "idiva",

	[COMPAT_KERNEL_HWCAP(IDIVT)]	= "idivt",

	[COMPAT_KERNEL_HWCAP(VFPD32)]	= NULL,	/* Not possible on arm64 */

	[COMPAT_KERNEL_HWCAP(LPAE)]	= "lpae",

	[COMPAT_KERNEL_HWCAP(EVTSTRM)]	= "evtstrm",

};



#define COMPAT_KERNEL_HWCAP2(x)	const_ilog2(COMPAT_HWCAP2_ ## x)

static const char *const compat_hwcap2_str[] = {

	"aes",

	"pmull",

	"sha1",

	"sha2",

	"crc32",

	NULL

	[COMPAT_KERNEL_HWCAP2(AES)]	= "aes",

	[COMPAT_KERNEL_HWCAP2(PMULL)]	= "pmull",

	[COMPAT_KERNEL_HWCAP2(SHA1)]	= "sha1",

	[COMPAT_KERNEL_HWCAP2(SHA2)]	= "sha2",

	[COMPAT_KERNEL_HWCAP2(CRC32)]	= "crc32",

};

#endif /* CONFIG_COMPAT */
@@ -166,16 +164,25 @@ static int c_show(struct seq_file *m, void *v) 
		seq_puts(m, "Features\t:");

		if (compat) {

#ifdef CONFIG_COMPAT

			for (j = 0; compat_hwcap_str[j]; j++)

				if (compat_elf_hwcap & (1 << j))

			for (j = 0; j < ARRAY_SIZE(compat_hwcap_str); j++) {

				if (compat_elf_hwcap & (1 << j)) {

					/*

					 * Warn once if any feature should not

					 * have been present on arm64 platform.

					 */

					if (WARN_ON_ONCE(!compat_hwcap_str[j]))

						continue;



					seq_printf(m, " %s", compat_hwcap_str[j]);

				}

			}



			for (j = 0; compat_hwcap2_str[j]; j++)

			for (j = 0; j < ARRAY_SIZE(compat_hwcap2_str); j++)

				if (compat_elf_hwcap2 & (1 << j))

					seq_printf(m, " %s", compat_hwcap2_str[j]);

#endif /* CONFIG_COMPAT */

		} else {

			for (j = 0; hwcap_str[j]; j++)

			for (j = 0; j < ARRAY_SIZE(hwcap_str); j++)

				if (cpu_have_feature(j))

					seq_printf(m, " %s", hwcap_str[j]);

		}

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