From 175fca3bf91a1111b7e46f6655666640556b9059 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Fri, 23 Aug 2019 21:49:13 +0200 Subject: kexec: add KEXEC_ELF Right now powerpc provides an implementation to read elf files with the kexec_file_load() syscall. Make that available as a public kexec interface so it can be re-used on other architectures. Signed-off-by: Sven Schnelle Reviewed-by: Thiago Jung Bauermann Signed-off-by: Helge Deller --- include/linux/kexec.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'include') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index b9b1bc5f9669..da2a6b1d69e7 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -216,6 +216,30 @@ extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, void **addr, unsigned long *sz); #endif /* CONFIG_KEXEC_FILE */ +#ifdef CONFIG_KEXEC_ELF +struct kexec_elf_info { + /* + * Where the ELF binary contents are kept. + * Memory managed by the user of the struct. + */ + const char *buffer; + + const struct elfhdr *ehdr; + const struct elf_phdr *proghdrs; + struct elf_shdr *sechdrs; +}; + +int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr, + struct kexec_elf_info *elf_info); + +int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr, + struct kexec_elf_info *elf_info, + struct kexec_buf *kbuf, + unsigned long *lowest_load_addr); + +void kexec_free_elf_info(struct kexec_elf_info *elf_info); +int kexec_elf_probe(const char *buf, unsigned long len); +#endif struct kimage { kimage_entry_t head; kimage_entry_t *entry; -- cgit v1.3-14-g43fede From 5f71d977206f3b2990ba304766ddaa9e81dbe700 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Fri, 23 Aug 2019 21:49:15 +0200 Subject: kexec_elf: remove parsing of section headers We're not using them, so we can drop the parsing. Signed-off-by: Sven Schnelle Reviewed-by: Thiago Jung Bauermann Signed-off-by: Helge Deller --- include/linux/kexec.h | 1 - kernel/kexec_elf.c | 137 -------------------------------------------------- 2 files changed, 138 deletions(-) (limited to 'include') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index da2a6b1d69e7..f0b809258ed3 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -226,7 +226,6 @@ struct kexec_elf_info { const struct elfhdr *ehdr; const struct elf_phdr *proghdrs; - struct elf_shdr *sechdrs; }; int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr, diff --git a/kernel/kexec_elf.c b/kernel/kexec_elf.c index 34376fbc55be..137037603117 100644 --- a/kernel/kexec_elf.c +++ b/kernel/kexec_elf.c @@ -257,134 +257,6 @@ static int elf_read_phdrs(const char *buf, size_t len, return 0; } -/** - * elf_is_shdr_sane - check that it is safe to use the section header - * @buf_len: size of the buffer in which the ELF file is loaded. - */ -static bool elf_is_shdr_sane(const struct elf_shdr *shdr, size_t buf_len) -{ - bool size_ok; - - /* SHT_NULL headers have undefined values, so we can't check them. */ - if (shdr->sh_type == SHT_NULL) - return true; - - /* Now verify sh_entsize */ - switch (shdr->sh_type) { - case SHT_SYMTAB: - size_ok = shdr->sh_entsize == sizeof(Elf_Sym); - break; - case SHT_RELA: - size_ok = shdr->sh_entsize == sizeof(Elf_Rela); - break; - case SHT_DYNAMIC: - size_ok = shdr->sh_entsize == sizeof(Elf_Dyn); - break; - case SHT_REL: - size_ok = shdr->sh_entsize == sizeof(Elf_Rel); - break; - case SHT_NOTE: - case SHT_PROGBITS: - case SHT_HASH: - case SHT_NOBITS: - default: - /* - * This is a section whose entsize requirements - * I don't care about. If I don't know about - * the section I can't care about it's entsize - * requirements. - */ - size_ok = true; - break; - } - - if (!size_ok) { - pr_debug("ELF section with wrong entry size.\n"); - return false; - } else if (shdr->sh_addr + shdr->sh_size < shdr->sh_addr) { - pr_debug("ELF section address wraps around.\n"); - return false; - } - - if (shdr->sh_type != SHT_NOBITS) { - if (shdr->sh_offset + shdr->sh_size < shdr->sh_offset) { - pr_debug("ELF section location wraps around.\n"); - return false; - } else if (shdr->sh_offset + shdr->sh_size > buf_len) { - pr_debug("ELF section not in file.\n"); - return false; - } - } - - return true; -} - -static int elf_read_shdr(const char *buf, size_t len, - struct kexec_elf_info *elf_info, - int idx) -{ - struct elf_shdr *shdr = &elf_info->sechdrs[idx]; - const struct elfhdr *ehdr = elf_info->ehdr; - const char *sbuf; - struct elf_shdr *buf_shdr; - - sbuf = buf + ehdr->e_shoff + idx * sizeof(*buf_shdr); - buf_shdr = (struct elf_shdr *) sbuf; - - shdr->sh_name = elf32_to_cpu(ehdr, buf_shdr->sh_name); - shdr->sh_type = elf32_to_cpu(ehdr, buf_shdr->sh_type); - shdr->sh_addr = elf_addr_to_cpu(ehdr, buf_shdr->sh_addr); - shdr->sh_offset = elf_addr_to_cpu(ehdr, buf_shdr->sh_offset); - shdr->sh_link = elf32_to_cpu(ehdr, buf_shdr->sh_link); - shdr->sh_info = elf32_to_cpu(ehdr, buf_shdr->sh_info); - - /* - * The following fields have a type equivalent to Elf_Addr - * both in 32 bit and 64 bit ELF. - */ - shdr->sh_flags = elf_addr_to_cpu(ehdr, buf_shdr->sh_flags); - shdr->sh_size = elf_addr_to_cpu(ehdr, buf_shdr->sh_size); - shdr->sh_addralign = elf_addr_to_cpu(ehdr, buf_shdr->sh_addralign); - shdr->sh_entsize = elf_addr_to_cpu(ehdr, buf_shdr->sh_entsize); - - return elf_is_shdr_sane(shdr, len) ? 0 : -ENOEXEC; -} - -/** - * elf_read_shdrs - read the section headers from the buffer - * - * This function assumes that the section header table was checked for sanity. - * Use elf_is_ehdr_sane() if it wasn't. - */ -static int elf_read_shdrs(const char *buf, size_t len, - struct kexec_elf_info *elf_info) -{ - size_t shdr_size, i; - - /* - * e_shnum is at most 65536 so calculating - * the size of the section header cannot overflow. - */ - shdr_size = sizeof(struct elf_shdr) * elf_info->ehdr->e_shnum; - - elf_info->sechdrs = kzalloc(shdr_size, GFP_KERNEL); - if (!elf_info->sechdrs) - return -ENOMEM; - - for (i = 0; i < elf_info->ehdr->e_shnum; i++) { - int ret; - - ret = elf_read_shdr(buf, len, elf_info, i); - if (ret) { - kfree(elf_info->sechdrs); - elf_info->sechdrs = NULL; - return ret; - } - } - - return 0; -} - /** * elf_read_from_buffer - read ELF file and sets up ELF header and ELF info * @buf: Buffer to read ELF file from. @@ -417,14 +289,6 @@ static int elf_read_from_buffer(const char *buf, size_t len, if (ret) return ret; } - if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) { - ret = elf_read_shdrs(buf, len, elf_info); - if (ret) { - kfree(elf_info->proghdrs); - return ret; - } - } - return 0; } @@ -434,7 +298,6 @@ static int elf_read_from_buffer(const char *buf, size_t len, void kexec_free_elf_info(struct kexec_elf_info *elf_info) { kfree(elf_info->proghdrs); - kfree(elf_info->sechdrs); memset(elf_info, 0, sizeof(*elf_info)); } /** -- cgit v1.3-14-g43fede From fc697dc0c26a5908d467454e49440862d7fe96d0 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Sun, 8 Sep 2019 11:33:04 +0200 Subject: parisc: add kexec syscall support Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller --- arch/parisc/Kconfig | 13 +++ arch/parisc/include/asm/fixmap.h | 1 + arch/parisc/include/asm/kexec.h | 37 +++++++++ arch/parisc/kernel/Makefile | 1 + arch/parisc/kernel/kexec.c | 105 ++++++++++++++++++++++++ arch/parisc/kernel/relocate_kernel.S | 149 +++++++++++++++++++++++++++++++++++ include/uapi/linux/kexec.h | 1 + 7 files changed, 307 insertions(+) create mode 100644 arch/parisc/include/asm/kexec.h create mode 100644 arch/parisc/kernel/kexec.c create mode 100644 arch/parisc/kernel/relocate_kernel.S (limited to 'include') diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index ee59171edffe..548c767f4358 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -346,6 +346,19 @@ config NR_CPUS depends on SMP default "4" +config KEXEC + bool "Kexec system call" + select KEXEC_CORE + help + kexec is a system call that implements the ability to shutdown your + current kernel, and to start another kernel. It is like a reboot + but it is independent of the system firmware. And like a reboot + you can start any kernel with it, not just Linux. + + It is an ongoing process to be certain the hardware in a machine + shutdown, so do not be surprised if this code does not + initially work for you. + endmenu diff --git a/arch/parisc/include/asm/fixmap.h b/arch/parisc/include/asm/fixmap.h index 288da73d4cc0..e480b2c05407 100644 --- a/arch/parisc/include/asm/fixmap.h +++ b/arch/parisc/include/asm/fixmap.h @@ -30,6 +30,7 @@ enum fixed_addresses { /* Support writing RO kernel text via kprobes, jump labels, etc. */ FIX_TEXT_POKE0, + FIX_TEXT_KEXEC, FIX_BITMAP_COUNT }; diff --git a/arch/parisc/include/asm/kexec.h b/arch/parisc/include/asm/kexec.h new file mode 100644 index 000000000000..a99ea747d7ed --- /dev/null +++ b/arch/parisc/include/asm/kexec.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_PARISC_KEXEC_H +#define _ASM_PARISC_KEXEC_H + +#ifdef CONFIG_KEXEC + +/* Maximum physical address we can use pages from */ +#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL) +/* Maximum address we can reach in physical address mode */ +#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL) +/* Maximum address we can use for the control code buffer */ +#define KEXEC_CONTROL_MEMORY_LIMIT (-1UL) + +#define KEXEC_CONTROL_PAGE_SIZE 4096 + +#define KEXEC_ARCH KEXEC_ARCH_PARISC +#define ARCH_HAS_KIMAGE_ARCH + +#ifndef __ASSEMBLY__ + +struct kimage_arch { + unsigned long initrd_start; + unsigned long initrd_end; + unsigned long cmdline; +}; + +static inline void crash_setup_regs(struct pt_regs *newregs, + struct pt_regs *oldregs) +{ + /* Dummy implementation for now */ +} + +#endif /* __ASSEMBLY__ */ + +#endif /* CONFIG_KEXEC */ + +#endif /* _ASM_PARISC_KEXEC_H */ diff --git a/arch/parisc/kernel/Makefile b/arch/parisc/kernel/Makefile index c232266b517c..487cf88866a8 100644 --- a/arch/parisc/kernel/Makefile +++ b/arch/parisc/kernel/Makefile @@ -37,3 +37,4 @@ obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_KPROBES) += kprobes.o +obj-$(CONFIG_KEXEC) += kexec.o relocate_kernel.o diff --git a/arch/parisc/kernel/kexec.c b/arch/parisc/kernel/kexec.c new file mode 100644 index 000000000000..a92d265a2261 --- /dev/null +++ b/arch/parisc/kernel/kexec.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include +#include + +extern void relocate_new_kernel(unsigned long head, + unsigned long start, + unsigned long phys); + +extern const unsigned int relocate_new_kernel_size; +extern unsigned int kexec_initrd_start_offset; +extern unsigned int kexec_initrd_end_offset; +extern unsigned int kexec_cmdline_offset; +extern unsigned int kexec_free_mem_offset; + +static void kexec_show_segment_info(const struct kimage *kimage, + unsigned long n) +{ + pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n", + n, + kimage->segment[n].mem, + kimage->segment[n].mem + kimage->segment[n].memsz, + (unsigned long)kimage->segment[n].memsz, + (unsigned long)kimage->segment[n].memsz / PAGE_SIZE); +} + +static void kexec_image_info(const struct kimage *kimage) +{ + unsigned long i; + + pr_debug("kexec kimage info:\n"); + pr_debug(" type: %d\n", kimage->type); + pr_debug(" start: %lx\n", kimage->start); + pr_debug(" head: %lx\n", kimage->head); + pr_debug(" nr_segments: %lu\n", kimage->nr_segments); + + for (i = 0; i < kimage->nr_segments; i++) + kexec_show_segment_info(kimage, i); +} + +void machine_kexec_cleanup(struct kimage *kimage) +{ +} + +void machine_crash_shutdown(struct pt_regs *regs) +{ +} + +void machine_shutdown(void) +{ + smp_send_stop(); + while (num_online_cpus() > 1) { + cpu_relax(); + mdelay(1); + } +} + +void machine_kexec(struct kimage *image) +{ +#ifdef CONFIG_64BIT + Elf64_Fdesc desc; +#endif + void (*reloc)(unsigned long head, + unsigned long start, + unsigned long phys); + + unsigned long phys = page_to_phys(image->control_code_page); + void *virt = (void *)__fix_to_virt(FIX_TEXT_KEXEC); + struct kimage_arch *arch = &image->arch; + + set_fixmap(FIX_TEXT_KEXEC, phys); + + flush_cache_all(); + +#ifdef CONFIG_64BIT + reloc = (void *)&desc; + desc.addr = (long long)virt; +#else + reloc = (void *)virt; +#endif + + memcpy(virt, dereference_function_descriptor(relocate_new_kernel), + relocate_new_kernel_size); + + *(unsigned long *)(virt + kexec_cmdline_offset) = arch->cmdline; + *(unsigned long *)(virt + kexec_initrd_start_offset) = arch->initrd_start; + *(unsigned long *)(virt + kexec_initrd_end_offset) = arch->initrd_end; + *(unsigned long *)(virt + kexec_free_mem_offset) = PAGE0->mem_free; + + flush_cache_all(); + flush_tlb_all(); + local_irq_disable(); + + reloc(image->head & PAGE_MASK, image->start, phys); +} + +int machine_kexec_prepare(struct kimage *image) +{ + kexec_image_info(image); + return 0; +} diff --git a/arch/parisc/kernel/relocate_kernel.S b/arch/parisc/kernel/relocate_kernel.S new file mode 100644 index 000000000000..2561e52b8d9b --- /dev/null +++ b/arch/parisc/kernel/relocate_kernel.S @@ -0,0 +1,149 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#include + +#include +#include +#include +#include +#include + +.level PA_ASM_LEVEL + +.macro kexec_param name +.align 8 +ENTRY(kexec\()_\name) +#ifdef CONFIG_64BIT + .dword 0 +#else + .word 0 +#endif + +ENTRY(kexec\()_\name\()_offset) + .word kexec\()_\name - relocate_new_kernel +.endm + +.text + +/* args: + * r26 - kimage->head + * r25 - start address of kernel + * r24 - physical address of relocate code + */ + +ENTRY_CFI(relocate_new_kernel) +0: copy %arg1, %rp + /* disable I and Q bit, so we are allowed to execute RFI */ + rsm PSW_SM_I, %r0 + nop + nop + nop + nop + nop + nop + nop + + rsm PSW_SM_Q, %r0 + nop + nop + nop + nop + nop + nop + nop + + /* + * After return-from-interrupt, we want to run without Code/Data + * translation enabled just like on a normal boot. + */ + + /* calculate new physical execution address */ + ldo 1f-0b(%arg2), %r1 + mtctl %r0, %cr17 /* IIASQ */ + mtctl %r0, %cr17 /* IIASQ */ + mtctl %r1, %cr18 /* IIAOQ */ + ldo 4(%r1),%r1 + mtctl %r1, %cr18 /* IIAOQ */ +#ifdef CONFIG_64BIT + depdi,z 1, PSW_W_BIT, 1, %r1 + mtctl %r1, %cr22 /* IPSW */ +#else + mtctl %r0, %cr22 /* IPSW */ +#endif + /* lets go... */ + rfi +1: nop + nop + +.Lloop: + LDREG,ma REG_SZ(%arg0), %r3 + /* If crash kernel, no copy needed */ + cmpib,COND(=),n 0,%r3,boot + + bb,<,n %r3, 31 - IND_DONE_BIT, boot + bb,>=,n %r3, 31 - IND_INDIRECTION_BIT, .Lnotind + /* indirection, load and restart */ + movb %r3, %arg0, .Lloop + depi 0, 31, PAGE_SHIFT, %arg0 + +.Lnotind: + bb,>=,n %r3, 31 - IND_DESTINATION_BIT, .Lnotdest + b .Lloop + copy %r3, %r20 + +.Lnotdest: + bb,>= %r3, 31 - IND_SOURCE_BIT, .Lloop + depi 0, 31, PAGE_SHIFT, %r3 + copy %r3, %r21 + + /* copy page */ + copy %r0, %r18 + zdepi 1, 31 - PAGE_SHIFT, 1, %r18 + add %r20, %r18, %r17 + + depi 0, 31, PAGE_SHIFT, %r20 +.Lcopy: + copy %r20, %r12 + LDREG,ma REG_SZ(%r21), %r8 + LDREG,ma REG_SZ(%r21), %r9 + LDREG,ma REG_SZ(%r21), %r10 + LDREG,ma REG_SZ(%r21), %r11 + STREG,ma %r8, REG_SZ(%r20) + STREG,ma %r9, REG_SZ(%r20) + STREG,ma %r10, REG_SZ(%r20) + STREG,ma %r11, REG_SZ(%r20) + +#ifndef CONFIG_64BIT + LDREG,ma REG_SZ(%r21), %r8 + LDREG,ma REG_SZ(%r21), %r9 + LDREG,ma REG_SZ(%r21), %r10 + LDREG,ma REG_SZ(%r21), %r11 + STREG,ma %r8, REG_SZ(%r20) + STREG,ma %r9, REG_SZ(%r20) + STREG,ma %r10, REG_SZ(%r20) + STREG,ma %r11, REG_SZ(%r20) +#endif + + fdc %r0(%r12) + cmpb,COND(<<) %r20,%r17,.Lcopy + fic (%sr4, %r12) + b,n .Lloop + +boot: + mtctl %r0, %cr15 + + LDREG kexec_free_mem-0b(%arg2), %arg0 + LDREG kexec_cmdline-0b(%arg2), %arg1 + LDREG kexec_initrd_end-0b(%arg2), %arg3 + LDREG kexec_initrd_start-0b(%arg2), %arg2 + bv,n %r0(%rp) + +ENDPROC_CFI(relocate_new_kernel); + +ENTRY(relocate_new_kernel_size) + .word relocate_new_kernel_size - relocate_new_kernel + +kexec_param cmdline +kexec_param initrd_start +kexec_param initrd_end +kexec_param free_mem diff --git a/include/uapi/linux/kexec.h b/include/uapi/linux/kexec.h index 6d112868272d..05669c87a0af 100644 --- a/include/uapi/linux/kexec.h +++ b/include/uapi/linux/kexec.h @@ -31,6 +31,7 @@ #define KEXEC_ARCH_DEFAULT ( 0 << 16) #define KEXEC_ARCH_386 ( 3 << 16) #define KEXEC_ARCH_68K ( 4 << 16) +#define KEXEC_ARCH_PARISC (15 << 16) #define KEXEC_ARCH_X86_64 (62 << 16) #define KEXEC_ARCH_PPC (20 << 16) #define KEXEC_ARCH_PPC64 (21 << 16) -- cgit v1.3-14-g43fede