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.
Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Will Deacon <w...@kernel.org> Cc: Mark Brown <broo...@kernel.org> Cc: Dave Martin <dave.mar...@arm.com> Cc: Ard Biesheuvel <a...@kernel.org> Cc: Mark Rutland <mark.rutl...@arm.com> Cc: Suzuki K Poulose <suzuki.poul...@arm.com> Cc: linux-arm-ker...@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khand...@arm.com> --- This applies on 5.9-rc1 Mark, since the patch has changed I have dropped your Acked-by: tag. Are you happy to give a new one ? Changes in V3: - Moved name arrays to (arch/arm64/kernel/cpuinfo.c) to prevent a build warning - Replaced string values with NULL for all compat features not possible on arm64 - Changed compat_hwcap_str[] iteration on size as some NULL values are expected - Warn once after detecting any feature on arm64 that is not expected Changes in V2: (https://patchwork.kernel.org/patch/11533755/) - Defined COMPAT_KERNEL_HWCAP[2] and updated the name arrays per Mark - Updated the commit message as required Changes in V1: (https://patchwork.kernel.org/patch/11532945/) arch/arm64/include/asm/hwcap.h | 9 +++ arch/arm64/kernel/cpuinfo.c | 172 ++++++++++++++++++++++------------------- 2 files changed, 100 insertions(+), 81 deletions(-) diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 22f73fe..6493a4c 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -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) diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 393c6fb..382cb4c 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -43,94 +43,95 @@ 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", + [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", /* reserved for "mte" */ NULL }; #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", + NULL, }; #endif /* CONFIG_COMPAT */ @@ -166,9 +167,18 @@ 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++) if (compat_elf_hwcap2 & (1 << j)) -- 2.7.4
