Messages in this thread Patch in this message | | | From | 黄杰 <> | Date | Mon, 25 Jul 2022 20:56:19 +0800 | Subject | Fwd: [PATCH 2/4] kexec: add CONFING_KEXEC_PURGATORY_SKIP_SIG |
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---------- Forwarded message --------- 发件人: Albert Huang <huangjie.albert@bytedance.com> Date: 2022年7月25日周一 16:40 Subject: [PATCH 2/4] kexec: add CONFING_KEXEC_PURGATORY_SKIP_SIG To: Cc: huangjie.albert <huangjie.albert@bytedance.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>, <x86@kernel.org>, H. Peter Anvin <hpa@zytor.com>, Eric Biederman <ebiederm@xmission.com>, Masahiro Yamada <masahiroy@kernel.org>, Michal Marek <michal.lkml@markovi.net>, Nick Desaulniers <ndesaulniers@google.com>, Kirill A. Shutemov <kirill.shutemov@linux.intel.com>, Brijesh Singh <brijesh.singh@amd.com>, Michael Roth <michael.roth@amd.com>, Nathan Chancellor <nathan@kernel.org>, Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>, Ard Biesheuvel <ardb@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Sean Christopherson <seanjc@google.com>, Joerg Roedel <jroedel@suse.de>, Mark Rutland <mark.rutland@arm.com>, Kees Cook <keescook@chromium.org>, <linux-kernel@vger.kernel.org>, <kexec@lists.infradead.org>, <linux-kbuild@vger.kernel.org>
From: "huangjie.albert" <huangjie.albert@bytedance.com>
the verify_sha256_digest may cost 300+ ms in my test environment: bzImage: 53M initramfs:28M
We can add a macro to control whether to enable this check. If we can confirm that the data in this will not change, we can turn off the check and get a faster startup.
Signed-off-by: huangjie.albert <huangjie.albert@bytedance.com> --- arch/x86/Kconfig | 9 +++++++++ arch/x86/purgatory/purgatory.c | 7 +++++++ 2 files changed, 16 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 52a7f91527fe..adbd3a2bd60f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2052,6 +2052,15 @@ config KEXEC_BZIMAGE_VERIFY_SIG help Enable bzImage signature verification support.
+config KEXEC_PURGATORY_SKIP_SIG + bool "skip kexec purgatory signature verification" + depends on ARCH_HAS_KEXEC_PURGATORY + help + this options makes the kexec purgatory do not signature verification + which would get hundreds of milliseconds saved during kexec boot. If we can + confirm that the data of each segment loaded by kexec will not change we may + enable this option + config CRASH_DUMP bool "kernel crash dumps" depends on X86_64 || (X86_32 && HIGHMEM) diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c index 7558139920f8..b3f15774d86d 100644 --- a/arch/x86/purgatory/purgatory.c +++ b/arch/x86/purgatory/purgatory.c @@ -20,6 +20,12 @@ u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(".kexec-purgatory");
struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX] __section(".kexec-purgatory");
+#ifdef CONFIG_KEXEC_PURGATORY_SKIP_SIG +static int verify_sha256_digest(void) +{ + return 0; +} +#else static int verify_sha256_digest(void) { struct kexec_sha_region *ptr, *end; @@ -39,6 +45,7 @@ static int verify_sha256_digest(void)
return 0; } +#endif
void purgatory(void) { -- 2.31.1
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