From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9E16C433EF for ; Fri, 10 Dec 2021 06:57:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233204AbhLJHAr (ORCPT ); Fri, 10 Dec 2021 02:00:47 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:32900 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237140AbhLJHAN (ORCPT ); Fri, 10 Dec 2021 02:00:13 -0500 Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4J9MBZ6NW3zcdMX; Fri, 10 Dec 2021 14:56:22 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Fri, 10 Dec 2021 14:56:36 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Fri, 10 Dec 2021 14:56:35 +0800 From: Zhen Lei To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , , "H . Peter Anvin" , , Dave Young , Baoquan He , Vivek Goyal , Eric Biederman , , Catalin Marinas , "Will Deacon" , , Rob Herring , Frank Rowand , , Jonathan Corbet , CC: Zhen Lei , Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou Subject: [PATCH v17 05/10] x86: kdump: move reserve_crashkernel[_low]() into crash_core.c Date: Fri, 10 Dec 2021 14:55:28 +0800 Message-ID: <20211210065533.2023-6-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20211210065533.2023-1-thunder.leizhen@huawei.com> References: <20211210065533.2023-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chen Zhou Make the functions reserve_crashkernel[_low]() as generic. Since reserve_crashkernel[_low]() implementations are quite similar on other architectures as well, we can have more users of this later. So have CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL in arch/Kconfig and select this by X86. Signed-off-by: Chen Zhou Signed-off-by: Zhen Lei Tested-by: John Donnelly Tested-by: Dave Kleikamp --- arch/Kconfig | 3 + arch/x86/Kconfig | 2 + arch/x86/include/asm/elf.h | 3 + arch/x86/include/asm/kexec.h | 28 ++++++- arch/x86/kernel/setup.c | 143 +------------------------------- include/linux/crash_core.h | 3 + include/linux/kexec.h | 2 - kernel/crash_core.c | 156 +++++++++++++++++++++++++++++++++++ kernel/kexec_core.c | 17 ---- 9 files changed, 194 insertions(+), 163 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index d3c4ab249e9c275..7bdb32c41985dc5 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -24,6 +24,9 @@ config KEXEC_ELF config HAVE_IMA_KEXEC bool +config ARCH_WANT_RESERVE_CRASH_KERNEL + bool + config SET_FS bool diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5c2ccb85f2efb86..bd78ed8193079b9 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -12,6 +12,7 @@ config X86_32 depends on !64BIT # Options that are inherently 32-bit kernel only: select ARCH_WANT_IPC_PARSE_VERSION + select ARCH_WANT_RESERVE_CRASH_KERNEL if KEXEC_CORE select CLKSRC_I8253 select CLONE_BACKWARDS select GENERIC_VDSO_32 @@ -28,6 +29,7 @@ config X86_64 select ARCH_HAS_GIGANTIC_PAGE select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 select ARCH_USE_CMPXCHG_LOCKREF + select ARCH_WANT_RESERVE_CRASH_KERNEL if KEXEC_CORE select HAVE_ARCH_SOFT_DIRTY select MODULES_USE_ELF_RELA select NEED_DMA_MAP_STATE diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 29fea180a6658e8..7a6c36cff8331f5 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -94,6 +94,9 @@ extern unsigned int vdso32_enabled; #define elf_check_arch(x) elf_check_arch_ia32(x) +/* We can also handle crash dumps from 64 bit kernel. */ +# define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64) + /* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx contains a pointer to a function which might be registered using `atexit'. This provides a mean for the dynamic linker to call DT_FINI functions for diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index 3a22e65262aa70b..3ff38a1353a2b86 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -21,6 +21,27 @@ /* 16M alignment for crash kernel regions */ #define CRASH_ALIGN SZ_16M +/* + * Keep the crash kernel below this limit. + * + * Earlier 32-bits kernels would limit the kernel to the low 512 MB range + * due to mapping restrictions. + * + * 64-bit kdump kernels need to be restricted to be under 64 TB, which is + * the upper limit of system RAM in 4-level paging mode. Since the kdump + * jump could be from 5-level paging to 4-level paging, the jump will fail if + * the kernel is put above 64 TB, and during the 1st kernel bootup there's + * no good way to detect the paging mode of the target kernel which will be + * loaded for dumping. + */ +#ifdef CONFIG_X86_32 +# define CRASH_ADDR_LOW_MAX SZ_512M +# define CRASH_ADDR_HIGH_MAX SZ_512M +#else +# define CRASH_ADDR_LOW_MAX SZ_4G +# define CRASH_ADDR_HIGH_MAX SZ_64T +#endif + #ifndef __ASSEMBLY__ #include @@ -51,9 +72,6 @@ struct kimage; /* The native architecture */ # define KEXEC_ARCH KEXEC_ARCH_386 - -/* We can also handle crash dumps from 64 bit kernel. */ -# define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64) #else /* Maximum physical address we can use pages from */ # define KEXEC_SOURCE_MEMORY_LIMIT (MAXMEM-1) @@ -195,6 +213,10 @@ typedef void crash_vmclear_fn(void); extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss; extern void kdump_nmi_shootdown_cpus(void); +#ifdef CONFIG_KEXEC_CORE +extern void __init reserve_crashkernel(void); +#endif + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 7ae00716a208f82..5519baa7f4b964e 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include #include @@ -386,147 +387,7 @@ static void __init memblock_x86_reserve_range_setup_data(void) } } -/* - * --------- Crashkernel reservation ------------------------------ - */ - -#ifdef CONFIG_KEXEC_CORE - -/* - * Keep the crash kernel below this limit. - * - * Earlier 32-bits kernels would limit the kernel to the low 512 MB range - * due to mapping restrictions. - * - * 64-bit kdump kernels need to be restricted to be under 64 TB, which is - * the upper limit of system RAM in 4-level paging mode. Since the kdump - * jump could be from 5-level paging to 4-level paging, the jump will fail if - * the kernel is put above 64 TB, and during the 1st kernel bootup there's - * no good way to detect the paging mode of the target kernel which will be - * loaded for dumping. - */ -#ifdef CONFIG_X86_32 -# define CRASH_ADDR_LOW_MAX SZ_512M -# define CRASH_ADDR_HIGH_MAX SZ_512M -#else -# define CRASH_ADDR_LOW_MAX SZ_4G -# define CRASH_ADDR_HIGH_MAX SZ_64T -#endif - -static int __init reserve_crashkernel_low(void) -{ -#ifdef CONFIG_X86_64 - unsigned long long base, low_base = 0, low_size = 0; - unsigned long low_mem_limit; - int ret; - - low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX); - - /* crashkernel=Y,low */ - ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base); - if (ret) { - /* - * two parts from kernel/dma/swiotlb.c: - * -swiotlb size: user-specified with swiotlb= or default. - * - * -swiotlb overflow buffer: now hardcoded to 32k. We round it - * to 8M for other buffers that may need to stay low too. Also - * make sure we allocate enough extra low memory so that we - * don't run out of DMA buffers for 32-bit devices. - */ - low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); - } else { - /* passed with crashkernel=0,low ? */ - if (!low_size) - return 0; - } - - low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, CRASH_ALIGN, - CRASH_ADDR_LOW_MAX); - if (!low_base) { - pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n", - (unsigned long)(low_size >> 20)); - return -ENOMEM; - } - - pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n", - (unsigned long)(low_size >> 20), - (unsigned long)(low_base >> 20), - (unsigned long)(low_mem_limit >> 20)); - - crashk_low_res.start = low_base; - crashk_low_res.end = low_base + low_size - 1; -#endif - return 0; -} - -static void __init reserve_crashkernel(void) -{ - unsigned long long crash_size, crash_base, total_mem; - bool high = false; - int ret; - - total_mem = memblock_phys_mem_size(); - - /* crashkernel=XM */ - ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); - if (ret != 0 || crash_size <= 0) { - /* crashkernel=X,high */ - ret = parse_crashkernel_high(boot_command_line, total_mem, - &crash_size, &crash_base); - if (ret != 0 || crash_size <= 0) - return; - high = true; - } - - /* 0 means: find the address automatically */ - if (!crash_base) { - /* - * Set CRASH_ADDR_LOW_MAX upper bound for crash memory, - * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX, - * also allocates 256M extra low memory for DMA buffers - * and swiotlb. - * But the extra memory is not required for all machines. - * So try low memory first and fall back to high memory - * unless "crashkernel=size[KMG],high" is specified. - */ - if (!high) - crash_base = memblock_phys_alloc_range(crash_size, - CRASH_ALIGN, CRASH_ALIGN, - CRASH_ADDR_LOW_MAX); - if (!crash_base) - crash_base = memblock_phys_alloc_range(crash_size, - CRASH_ALIGN, CRASH_ALIGN, - CRASH_ADDR_HIGH_MAX); - if (!crash_base) { - pr_info("crashkernel reservation failed - No suitable area found.\n"); - return; - } - } else { - unsigned long long start; - - start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base, - crash_base + crash_size); - if (start != crash_base) { - pr_info("crashkernel reservation failed - memory is in use.\n"); - return; - } - } - - if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { - memblock_phys_free(crash_base, crash_size); - return; - } - - pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n", - (unsigned long)(crash_size >> 20), - (unsigned long)(crash_base >> 20), - (unsigned long)(total_mem >> 20)); - - crashk_res.start = crash_base; - crashk_res.end = crash_base + crash_size - 1; -} -#else +#ifndef CONFIG_KEXEC_CORE static void __init reserve_crashkernel(void) { } diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h index de62a722431e7db..f6b99da4ed08ecf 100644 --- a/include/linux/crash_core.h +++ b/include/linux/crash_core.h @@ -73,6 +73,9 @@ extern unsigned char *vmcoreinfo_data; extern size_t vmcoreinfo_size; extern u32 *vmcoreinfo_note; +extern struct resource crashk_res; +extern struct resource crashk_low_res; + Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, void *data, size_t data_len); void final_note(Elf_Word *buf); diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 0c994ae37729e1e..cd744d962f6f417 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -352,8 +352,6 @@ extern int kexec_load_disabled; /* Location of a reserved region to hold the crash kernel. */ -extern struct resource crashk_res; -extern struct resource crashk_low_res; extern note_buf_t __percpu *crash_notes; /* flag to track if kexec reboot is in progress */ diff --git a/kernel/crash_core.c b/kernel/crash_core.c index eb53f5ec62c900f..b23cfc0ca8905fd 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -8,6 +8,12 @@ #include #include #include +#include +#include + +#ifdef CONFIG_KEXEC_CORE +#include +#endif #include #include @@ -22,6 +28,22 @@ u32 *vmcoreinfo_note; /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */ static unsigned char *vmcoreinfo_data_safecopy; +/* Location of the reserved area for the crash kernel */ +struct resource crashk_res = { + .name = "Crash kernel", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, + .desc = IORES_DESC_CRASH_KERNEL +}; +struct resource crashk_low_res = { + .name = "Crash kernel", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, + .desc = IORES_DESC_CRASH_KERNEL +}; + /* * parsing the "crashkernel" commandline * @@ -295,6 +317,140 @@ int __init parse_crashkernel_low(char *cmdline, "crashkernel=", suffix_tbl[SUFFIX_LOW]); } +/* + * --------- Crashkernel reservation ------------------------------ + */ + +#ifdef CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL +static int __init reserve_crashkernel_low(void) +{ +#ifdef CONFIG_64BIT + unsigned long long base, low_base = 0, low_size = 0; + unsigned long low_mem_limit; + int ret; + + low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX); + + /* crashkernel=Y,low */ + ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base); + if (ret) { + /* + * two parts from kernel/dma/swiotlb.c: + * -swiotlb size: user-specified with swiotlb= or default. + * + * -swiotlb overflow buffer: now hardcoded to 32k. We round it + * to 8M for other buffers that may need to stay low too. Also + * make sure we allocate enough extra low memory so that we + * don't run out of DMA buffers for 32-bit devices. + */ + low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); + } else { + /* passed with crashkernel=0,low ? */ + if (!low_size) + return 0; + } + + low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, CRASH_ALIGN, + CRASH_ADDR_LOW_MAX); + if (!low_base) { + pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n", + (unsigned long)(low_size >> 20)); + return -ENOMEM; + } + + pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n", + (unsigned long)(low_size >> 20), + (unsigned long)(low_base >> 20), + (unsigned long)(low_mem_limit >> 20)); + + crashk_low_res.start = low_base; + crashk_low_res.end = low_base + low_size - 1; +#endif + return 0; +} + +/* + * reserve_crashkernel() - reserves memory for crash kernel + * + * This function reserves memory area given in "crashkernel=" kernel command + * line parameter. The memory reserved is used by dump capture kernel when + * primary kernel is crashing. + */ +void __init reserve_crashkernel(void) +{ + unsigned long long crash_size, crash_base, total_mem; + bool high = false; + int ret; + + total_mem = memblock_phys_mem_size(); + + /* crashkernel=XM */ + ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); + if (ret != 0 || crash_size <= 0) { + /* crashkernel=X,high */ + ret = parse_crashkernel_high(boot_command_line, total_mem, + &crash_size, &crash_base); + if (ret != 0 || crash_size <= 0) + return; + high = true; + } + + /* 0 means: find the address automatically */ + if (!crash_base) { + /* + * Set CRASH_ADDR_LOW_MAX upper bound for crash memory, + * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX, + * also allocates 256M extra low memory for DMA buffers + * and swiotlb. + * But the extra memory is not required for all machines. + * So try low memory first and fall back to high memory + * unless "crashkernel=size[KMG],high" is specified. + */ + if (!high) + crash_base = memblock_phys_alloc_range(crash_size, + CRASH_ALIGN, CRASH_ALIGN, + CRASH_ADDR_LOW_MAX); + if (!crash_base) + crash_base = memblock_phys_alloc_range(crash_size, + CRASH_ALIGN, CRASH_ALIGN, + CRASH_ADDR_HIGH_MAX); + if (!crash_base) { + pr_info("crashkernel reservation failed - No suitable area found.\n"); + return; + } + } else { + /* User specifies base address explicitly. */ + unsigned long long start; + + if (!IS_ALIGNED(crash_base, CRASH_ALIGN)) { + pr_warn("cannot reserve crashkernel: base address is not %ldMB aligned\n", + (unsigned long)CRASH_ALIGN >> 20); + return; + } + + start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base, + crash_base + crash_size); + if (start != crash_base) { + pr_info("crashkernel reservation failed - memory is in use.\n"); + return; + } + } + + if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { + memblock_phys_free(crash_base, crash_size); + return; + } + + pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n", + (unsigned long)(crash_size >> 20), + (unsigned long)(crash_base >> 20), + (unsigned long)(total_mem >> 20)); + + crashk_res.start = crash_base; + crashk_res.end = crash_base + crash_size - 1; +} +#endif /* CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL */ + Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, void *data, size_t data_len) { diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 5a5d192a89ac307..1e0d4909bbb6b77 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -54,23 +54,6 @@ note_buf_t __percpu *crash_notes; /* Flag to indicate we are going to kexec a new kernel */ bool kexec_in_progress = false; - -/* Location of the reserved area for the crash kernel */ -struct resource crashk_res = { - .name = "Crash kernel", - .start = 0, - .end = 0, - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, - .desc = IORES_DESC_CRASH_KERNEL -}; -struct resource crashk_low_res = { - .name = "Crash kernel", - .start = 0, - .end = 0, - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, - .desc = IORES_DESC_CRASH_KERNEL -}; - int kexec_should_crash(struct task_struct *p) { /* -- 2.25.1