From 308c09f17da4adc53935115dbeb5bce4f067d8f9 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Fri, 8 Aug 2014 14:23:25 -0700 Subject: lib/scatterlist: make ARCH_HAS_SG_CHAIN an actual Kconfig Rather than have architectures #define ARCH_HAS_SG_CHAIN in an architecture specific scatterlist.h, make it a proper Kconfig option and use that instead. At same time, remove the header files are are now mostly useless and just include asm-generic/scatterlist.h. [sfr@canb.auug.org.au: powerpc files now need asm/dma.h] Signed-off-by: Laura Abbott Acked-by: Thomas Gleixner [x86] Acked-by: Benjamin Herrenschmidt [powerpc] Acked-by: Heiko Carstens Cc: Russell King Cc: Tony Luck Cc: Fenghua Yu Cc: Paul Mackerras Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: "James E.J. Bottomley" Cc: Martin Schwidefsky Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/Kconfig | 1 + arch/s390/include/asm/Kbuild | 1 + arch/s390/include/asm/scatterlist.h | 3 --- 3 files changed, 2 insertions(+), 3 deletions(-) delete mode 100644 arch/s390/include/asm/scatterlist.h (limited to 'arch/s390') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 8ca60f8d568..05c78bb5f57 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -145,6 +145,7 @@ config S390 select TTY select VIRT_CPU_ACCOUNTING select VIRT_TO_BUS + select ARCH_HAS_SG_CHAIN config SCHED_OMIT_FRAME_POINTER def_bool y diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild index 57892a8a905..b3fea0722ff 100644 --- a/arch/s390/include/asm/Kbuild +++ b/arch/s390/include/asm/Kbuild @@ -4,4 +4,5 @@ generic-y += clkdev.h generic-y += hash.h generic-y += mcs_spinlock.h generic-y += preempt.h +generic-y += scatterlist.h generic-y += trace_clock.h diff --git a/arch/s390/include/asm/scatterlist.h b/arch/s390/include/asm/scatterlist.h deleted file mode 100644 index 6d45ef6c12a..00000000000 --- a/arch/s390/include/asm/scatterlist.h +++ /dev/null @@ -1,3 +0,0 @@ -#include - -#define ARCH_HAS_SG_CHAIN -- cgit v1.2.3-70-g09d2 From a6c19dfe39941a5d3f4d072121c0a4841e7e26fd Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Fri, 8 Aug 2014 14:23:40 -0700 Subject: arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area The core mm code will provide a default gate area based on FIXADDR_USER_START and FIXADDR_USER_END if !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR). This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit UML, and x86_32 have their own code just to disable it. arm, 32-bit UML, and x86_64 have gate areas, but they have their own implementations. This gets rid of the default and moves the code into ia64. This should save some code on architectures without a gate area: it's now possible to inline the gate_area functions in the default case. Signed-off-by: Andy Lutomirski Acked-by: Nathan Lynch Acked-by: H. Peter Anvin Acked-by: Benjamin Herrenschmidt [in principle] Acked-by: Richard Weinberger [for um] Acked-by: Will Deacon [for arm64] Cc: Catalin Marinas Cc: Will Deacon Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chris Metcalf Cc: Jeff Dike Cc: Richard Weinberger Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Nathan Lynch Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm64/include/asm/page.h | 3 --- arch/arm64/kernel/vdso.c | 19 ------------------- arch/ia64/include/asm/page.h | 2 ++ arch/ia64/mm/init.c | 31 +++++++++++++++++++++++++++++++ arch/powerpc/include/asm/page.h | 3 --- arch/powerpc/kernel/vdso.c | 16 ---------------- arch/s390/include/asm/page.h | 2 -- arch/s390/kernel/vdso.c | 15 --------------- arch/sh/include/asm/page.h | 5 ----- arch/sh/kernel/vsyscall/vsyscall.c | 15 --------------- arch/tile/include/asm/page.h | 6 ------ arch/tile/kernel/vdso.c | 15 --------------- arch/um/include/asm/page.h | 5 +++++ arch/x86/include/asm/page.h | 1 - arch/x86/include/asm/page_64.h | 2 ++ arch/x86/um/asm/elf.h | 1 - arch/x86/um/mem_64.c | 15 --------------- arch/x86/vdso/vdso32-setup.c | 19 +------------------ include/linux/mm.h | 17 ++++++++++++----- mm/memory.c | 38 -------------------------------------- mm/nommu.c | 5 ----- 21 files changed, 53 insertions(+), 182 deletions(-) (limited to 'arch/s390') diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index 7a3f462133b..22b16232bd6 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -28,9 +28,6 @@ #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE-1)) -/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */ -#define __HAVE_ARCH_GATE_AREA 1 - /* * The idmap and swapper page tables need some space reserved in the kernel * image. Both require pgd, pud (4 levels only) and pmd tables to (section) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index a81a446a578..32aeea083d9 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -194,25 +194,6 @@ up_fail: return PTR_ERR(ret); } -/* - * We define AT_SYSINFO_EHDR, so we need these function stubs to keep - * Linux happy. - */ -int in_gate_area_no_mm(unsigned long addr) -{ - return 0; -} - -int in_gate_area(struct mm_struct *mm, unsigned long addr) -{ - return 0; -} - -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ - return NULL; -} - /* * Update the vDSO data page to keep in sync with kernel timekeeping. */ diff --git a/arch/ia64/include/asm/page.h b/arch/ia64/include/asm/page.h index f1e1b2e3cdb..1f1bf144fe6 100644 --- a/arch/ia64/include/asm/page.h +++ b/arch/ia64/include/asm/page.h @@ -231,4 +231,6 @@ get_order (unsigned long size) #define PERCPU_ADDR (-PERCPU_PAGE_SIZE) #define LOAD_OFFSET (KERNEL_START - KERNEL_TR_PAGE_SIZE) +#define __HAVE_ARCH_GATE_AREA 1 + #endif /* _ASM_IA64_PAGE_H */ diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c index 892d43e32f3..6b3345758d3 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -278,6 +278,37 @@ setup_gate (void) ia64_patch_gate(); } +static struct vm_area_struct gate_vma; + +static int __init gate_vma_init(void) +{ + gate_vma.vm_mm = NULL; + gate_vma.vm_start = FIXADDR_USER_START; + gate_vma.vm_end = FIXADDR_USER_END; + gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC; + gate_vma.vm_page_prot = __P101; + + return 0; +} +__initcall(gate_vma_init); + +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) +{ + return &gate_vma; +} + +int in_gate_area_no_mm(unsigned long addr) +{ + if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) + return 1; + return 0; +} + +int in_gate_area(struct mm_struct *mm, unsigned long addr) +{ + return in_gate_area_no_mm(addr); +} + void ia64_mmu_init(void *my_cpu_data) { unsigned long pta, impl_va_bits; diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index 32e4e212b9c..26fe1ae1521 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -48,9 +48,6 @@ extern unsigned int HPAGE_SHIFT; #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1) #endif -/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */ -#define __HAVE_ARCH_GATE_AREA 1 - /* * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we * assign PAGE_MASK to a larger type it gets extended the way we want diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index ce74c335a6a..f174351842c 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -840,19 +840,3 @@ static int __init vdso_init(void) return 0; } arch_initcall(vdso_init); - -int in_gate_area_no_mm(unsigned long addr) -{ - return 0; -} - -int in_gate_area(struct mm_struct *mm, unsigned long addr) -{ - return 0; -} - -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ - return NULL; -} - diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h index 114258eeaac..7b2ac6e4416 100644 --- a/arch/s390/include/asm/page.h +++ b/arch/s390/include/asm/page.h @@ -162,6 +162,4 @@ static inline int devmem_is_allowed(unsigned long pfn) #include #include -#define __HAVE_ARCH_GATE_AREA 1 - #endif /* _S390_PAGE_H */ diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index 61364909678..0bbb7e027c5 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -316,18 +316,3 @@ static int __init vdso_init(void) return 0; } early_initcall(vdso_init); - -int in_gate_area_no_mm(unsigned long addr) -{ - return 0; -} - -int in_gate_area(struct mm_struct *mm, unsigned long addr) -{ - return 0; -} - -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ - return NULL; -} diff --git a/arch/sh/include/asm/page.h b/arch/sh/include/asm/page.h index 15d970328f7..fe20d14ae05 100644 --- a/arch/sh/include/asm/page.h +++ b/arch/sh/include/asm/page.h @@ -186,11 +186,6 @@ typedef struct page *pgtable_t; #include #include -/* vDSO support */ -#ifdef CONFIG_VSYSCALL -#define __HAVE_ARCH_GATE_AREA -#endif - /* * Some drivers need to perform DMA into kmalloc'ed buffers * and so we have to increase the kmalloc minalign for this. diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c index 5ca579720a0..ea2aa1393b8 100644 --- a/arch/sh/kernel/vsyscall/vsyscall.c +++ b/arch/sh/kernel/vsyscall/vsyscall.c @@ -92,18 +92,3 @@ const char *arch_vma_name(struct vm_area_struct *vma) return NULL; } - -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ - return NULL; -} - -int in_gate_area(struct mm_struct *mm, unsigned long address) -{ - return 0; -} - -int in_gate_area_no_mm(unsigned long address) -{ - return 0; -} diff --git a/arch/tile/include/asm/page.h b/arch/tile/include/asm/page.h index 67276800861..a213a8d84a9 100644 --- a/arch/tile/include/asm/page.h +++ b/arch/tile/include/asm/page.h @@ -38,12 +38,6 @@ #define PAGE_MASK (~(PAGE_SIZE - 1)) #define HPAGE_MASK (~(HPAGE_SIZE - 1)) -/* - * We do define AT_SYSINFO_EHDR to support vDSO, - * but don't use the gate mechanism. - */ -#define __HAVE_ARCH_GATE_AREA 1 - /* * If the Kconfig doesn't specify, set a maximum zone order that * is enough so that we can create huge pages from small pages given diff --git a/arch/tile/kernel/vdso.c b/arch/tile/kernel/vdso.c index 1533af24106..5bc51d7dfdc 100644 --- a/arch/tile/kernel/vdso.c +++ b/arch/tile/kernel/vdso.c @@ -121,21 +121,6 @@ const char *arch_vma_name(struct vm_area_struct *vma) return NULL; } -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ - return NULL; -} - -int in_gate_area(struct mm_struct *mm, unsigned long address) -{ - return 0; -} - -int in_gate_area_no_mm(unsigned long address) -{ - return 0; -} - int setup_vdso_pages(void) { struct page **pagelist; diff --git a/arch/um/include/asm/page.h b/arch/um/include/asm/page.h index 5ff53d9185f..71c5d132062 100644 --- a/arch/um/include/asm/page.h +++ b/arch/um/include/asm/page.h @@ -119,4 +119,9 @@ extern unsigned long uml_physmem; #include #endif /* __ASSEMBLY__ */ + +#ifdef CONFIG_X86_32 +#define __HAVE_ARCH_GATE_AREA 1 +#endif + #endif /* __UM_PAGE_H */ diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h index 775873d3be5..802dde30c92 100644 --- a/arch/x86/include/asm/page.h +++ b/arch/x86/include/asm/page.h @@ -70,7 +70,6 @@ extern bool __virt_addr_valid(unsigned long kaddr); #include #include -#define __HAVE_ARCH_GATE_AREA 1 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA #endif /* __KERNEL__ */ diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h index 0f1ddee6a0c..f408caf7343 100644 --- a/arch/x86/include/asm/page_64.h +++ b/arch/x86/include/asm/page_64.h @@ -39,4 +39,6 @@ void copy_page(void *to, void *from); #endif /* !__ASSEMBLY__ */ +#define __HAVE_ARCH_GATE_AREA 1 + #endif /* _ASM_X86_PAGE_64_H */ diff --git a/arch/x86/um/asm/elf.h b/arch/x86/um/asm/elf.h index 0feee2fd507..25a1022dd79 100644 --- a/arch/x86/um/asm/elf.h +++ b/arch/x86/um/asm/elf.h @@ -216,6 +216,5 @@ extern long elf_aux_hwcap; #define ELF_HWCAP (elf_aux_hwcap) #define SET_PERSONALITY(ex) do ; while(0) -#define __HAVE_ARCH_GATE_AREA 1 #endif diff --git a/arch/x86/um/mem_64.c b/arch/x86/um/mem_64.c index c6492e75797..f8fecaddcc0 100644 --- a/arch/x86/um/mem_64.c +++ b/arch/x86/um/mem_64.c @@ -9,18 +9,3 @@ const char *arch_vma_name(struct vm_area_struct *vma) return NULL; } - -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ - return NULL; -} - -int in_gate_area(struct mm_struct *mm, unsigned long addr) -{ - return 0; -} - -int in_gate_area_no_mm(unsigned long addr) -{ - return 0; -} diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c index e4f7781ee16..e904c270573 100644 --- a/arch/x86/vdso/vdso32-setup.c +++ b/arch/x86/vdso/vdso32-setup.c @@ -115,23 +115,6 @@ static __init int ia32_binfmt_init(void) return 0; } __initcall(ia32_binfmt_init); -#endif - -#else /* CONFIG_X86_32 */ - -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ - return NULL; -} - -int in_gate_area(struct mm_struct *mm, unsigned long addr) -{ - return 0; -} - -int in_gate_area_no_mm(unsigned long addr) -{ - return 0; -} +#endif /* CONFIG_SYSCTL */ #endif /* CONFIG_X86_64 */ diff --git a/include/linux/mm.h b/include/linux/mm.h index e03dd29145a..8981cc882ed 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2014,13 +2014,20 @@ static inline bool kernel_page_present(struct page *page) { return true; } #endif /* CONFIG_HIBERNATION */ #endif +#ifdef __HAVE_ARCH_GATE_AREA extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm); -#ifdef __HAVE_ARCH_GATE_AREA -int in_gate_area_no_mm(unsigned long addr); -int in_gate_area(struct mm_struct *mm, unsigned long addr); +extern int in_gate_area_no_mm(unsigned long addr); +extern int in_gate_area(struct mm_struct *mm, unsigned long addr); #else -int in_gate_area_no_mm(unsigned long addr); -#define in_gate_area(mm, addr) ({(void)mm; in_gate_area_no_mm(addr);}) +static inline struct vm_area_struct *get_gate_vma(struct mm_struct *mm) +{ + return NULL; +} +static inline int in_gate_area_no_mm(unsigned long addr) { return 0; } +static inline int in_gate_area(struct mm_struct *mm, unsigned long addr) +{ + return 0; +} #endif /* __HAVE_ARCH_GATE_AREA */ #ifdef CONFIG_SYSCTL diff --git a/mm/memory.c b/mm/memory.c index 2a899e4e82b..ab3537bcfed 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3430,44 +3430,6 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) } #endif /* __PAGETABLE_PMD_FOLDED */ -#if !defined(__HAVE_ARCH_GATE_AREA) - -#if defined(AT_SYSINFO_EHDR) -static struct vm_area_struct gate_vma; - -static int __init gate_vma_init(void) -{ - gate_vma.vm_mm = NULL; - gate_vma.vm_start = FIXADDR_USER_START; - gate_vma.vm_end = FIXADDR_USER_END; - gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC; - gate_vma.vm_page_prot = __P101; - - return 0; -} -__initcall(gate_vma_init); -#endif - -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ -#ifdef AT_SYSINFO_EHDR - return &gate_vma; -#else - return NULL; -#endif -} - -int in_gate_area_no_mm(unsigned long addr) -{ -#ifdef AT_SYSINFO_EHDR - if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) - return 1; -#endif - return 0; -} - -#endif /* __HAVE_ARCH_GATE_AREA */ - static int __follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp, spinlock_t **ptlp) { diff --git a/mm/nommu.c b/mm/nommu.c index 4a852f6c570..a881d9673c6 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1981,11 +1981,6 @@ error: return -ENOMEM; } -int in_gate_area_no_mm(unsigned long addr) -{ - return 0; -} - int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { BUG(); -- cgit v1.2.3-70-g09d2 From 12db5562e0352986a265841638482b84f3a6899b Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 8 Aug 2014 14:26:04 -0700 Subject: kexec: load and relocate purgatory at kernel load time Load purgatory code in RAM and relocate it based on the location. Relocation code has been inspired by module relocation code and purgatory relocation code in kexec-tools. Also compute the checksums of loaded kexec segments and store them in purgatory. Arch independent code provides this functionality so that arch dependent bootloaders can make use of it. Helper functions are provided to get/set symbol values in purgatory which are used by bootloaders later to set things like stack and entry point of second kernel etc. Signed-off-by: Vivek Goyal Cc: Borislav Petkov Cc: Michael Kerrisk Cc: Yinghai Lu Cc: Eric Biederman Cc: H. Peter Anvin Cc: Matthew Garrett Cc: Greg Kroah-Hartman Cc: Dave Young Cc: WANG Chao Cc: Baoquan He Cc: Andy Lutomirski Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm/Kconfig | 2 + arch/ia64/Kconfig | 2 + arch/m68k/Kconfig | 2 + arch/mips/Kconfig | 2 + arch/powerpc/Kconfig | 2 + arch/s390/Kconfig | 2 + arch/sh/Kconfig | 2 + arch/tile/Kconfig | 2 + arch/x86/Kconfig | 2 + arch/x86/kernel/machine_kexec_64.c | 142 ++++++++++ include/linux/kexec.h | 33 +++ kernel/kexec.c | 544 ++++++++++++++++++++++++++++++++++++- 12 files changed, 736 insertions(+), 1 deletion(-) (limited to 'arch/s390') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 8e9dbcbcf5a..cacc8d5355b 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2065,6 +2065,8 @@ config XIP_PHYS_ADDR config KEXEC bool "Kexec system call (EXPERIMENTAL)" depends on (!SMP || PM_SLEEP_SMP) + select CRYPTO + select CRYPTO_SHA256 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 diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index c84c88bbbbd..64aefb76bd6 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -549,6 +549,8 @@ source "drivers/sn/Kconfig" config KEXEC bool "kexec system call" depends on !IA64_HP_SIM && (!SMP || HOTPLUG_CPU) + select CRYPTO + select CRYPTO_SHA256 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 diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 87b7c7581b1..3ff8c9a2533 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -91,6 +91,8 @@ config MMU_SUN3 config KEXEC bool "kexec system call" depends on M68KCLASSIC + select CRYPTO + select CRYPTO_SHA256 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 diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 900c7e5333b..df51e78a72c 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2396,6 +2396,8 @@ source "kernel/Kconfig.preempt" config KEXEC bool "Kexec system call" + select CRYPTO + select CRYPTO_SHA256 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 diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 4bc7b62fb4b..a577609f8ed 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -399,6 +399,8 @@ config PPC64_SUPPORTS_MEMORY_FAILURE config KEXEC bool "kexec system call" depends on (PPC_BOOK3S || FSL_BOOKE || (44x && !SMP)) + select CRYPTO + select CRYPTO_SHA256 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 diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 05c78bb5f57..ab39ceb89ec 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -48,6 +48,8 @@ config ARCH_SUPPORTS_DEBUG_PAGEALLOC config KEXEC def_bool y + select CRYPTO + select CRYPTO_SHA256 config AUDIT_ARCH def_bool y diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index aa2df3eaeb2..453fa5c0955 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -595,6 +595,8 @@ source kernel/Kconfig.hz config KEXEC bool "kexec system call (EXPERIMENTAL)" depends on SUPERH32 && MMU + select CRYPTO + select CRYPTO_SHA256 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 diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig index 7fcd492adbf..a3ffe2dd483 100644 --- a/arch/tile/Kconfig +++ b/arch/tile/Kconfig @@ -191,6 +191,8 @@ source "kernel/Kconfig.hz" config KEXEC bool "kexec system call" + select CRYPTO + select CRYPTO_SHA256 ---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 diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 98fe3df6df8..9558b9fcafb 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1583,6 +1583,8 @@ source kernel/Kconfig.hz config KEXEC bool "kexec system call" select BUILD_BIN2C + select CRYPTO + select CRYPTO_SHA256 ---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 diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index c8875b5545e..88404c44072 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -6,6 +6,8 @@ * Version 2. See the file COPYING for more details. */ +#define pr_fmt(fmt) "kexec: " fmt + #include #include #include @@ -328,3 +330,143 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image) return image->fops->cleanup(image); } + +/* + * Apply purgatory relocations. + * + * ehdr: Pointer to elf headers + * sechdrs: Pointer to section headers. + * relsec: section index of SHT_RELA section. + * + * TODO: Some of the code belongs to generic code. Move that in kexec.c. + */ +int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr, + Elf64_Shdr *sechdrs, unsigned int relsec) +{ + unsigned int i; + Elf64_Rela *rel; + Elf64_Sym *sym; + void *location; + Elf64_Shdr *section, *symtabsec; + unsigned long address, sec_base, value; + const char *strtab, *name, *shstrtab; + + /* + * ->sh_offset has been modified to keep the pointer to section + * contents in memory + */ + rel = (void *)sechdrs[relsec].sh_offset; + + /* Section to which relocations apply */ + section = &sechdrs[sechdrs[relsec].sh_info]; + + pr_debug("Applying relocate section %u to %u\n", relsec, + sechdrs[relsec].sh_info); + + /* Associated symbol table */ + symtabsec = &sechdrs[sechdrs[relsec].sh_link]; + + /* String table */ + if (symtabsec->sh_link >= ehdr->e_shnum) { + /* Invalid strtab section number */ + pr_err("Invalid string table section index %d\n", + symtabsec->sh_link); + return -ENOEXEC; + } + + strtab = (char *)sechdrs[symtabsec->sh_link].sh_offset; + + /* section header string table */ + shstrtab = (char *)sechdrs[ehdr->e_shstrndx].sh_offset; + + for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { + + /* + * rel[i].r_offset contains byte offset from beginning + * of section to the storage unit affected. + * + * This is location to update (->sh_offset). This is temporary + * buffer where section is currently loaded. This will finally + * be loaded to a different address later, pointed to by + * ->sh_addr. kexec takes care of moving it + * (kexec_load_segment()). + */ + location = (void *)(section->sh_offset + rel[i].r_offset); + + /* Final address of the location */ + address = section->sh_addr + rel[i].r_offset; + + /* + * rel[i].r_info contains information about symbol table index + * w.r.t which relocation must be made and type of relocation + * to apply. ELF64_R_SYM() and ELF64_R_TYPE() macros get + * these respectively. + */ + sym = (Elf64_Sym *)symtabsec->sh_offset + + ELF64_R_SYM(rel[i].r_info); + + if (sym->st_name) + name = strtab + sym->st_name; + else + name = shstrtab + sechdrs[sym->st_shndx].sh_name; + + pr_debug("Symbol: %s info: %02x shndx: %02x value=%llx size: %llx\n", + name, sym->st_info, sym->st_shndx, sym->st_value, + sym->st_size); + + if (sym->st_shndx == SHN_UNDEF) { + pr_err("Undefined symbol: %s\n", name); + return -ENOEXEC; + } + + if (sym->st_shndx == SHN_COMMON) { + pr_err("symbol '%s' in common section\n", name); + return -ENOEXEC; + } + + if (sym->st_shndx == SHN_ABS) + sec_base = 0; + else if (sym->st_shndx >= ehdr->e_shnum) { + pr_err("Invalid section %d for symbol %s\n", + sym->st_shndx, name); + return -ENOEXEC; + } else + sec_base = sechdrs[sym->st_shndx].sh_addr; + + value = sym->st_value; + value += sec_base; + value += rel[i].r_addend; + + switch (ELF64_R_TYPE(rel[i].r_info)) { + case R_X86_64_NONE: + break; + case R_X86_64_64: + *(u64 *)location = value; + break; + case R_X86_64_32: + *(u32 *)location = value; + if (value != *(u32 *)location) + goto overflow; + break; + case R_X86_64_32S: + *(s32 *)location = value; + if ((s64)value != *(s32 *)location) + goto overflow; + break; + case R_X86_64_PC32: + value -= (u64)address; + *(u32 *)location = value; + break; + default: + pr_err("Unknown rela relocation: %llu\n", + ELF64_R_TYPE(rel[i].r_info)); + return -ENOEXEC; + } + } + return 0; + +overflow: + pr_err("Overflow in relocation type %d value 0x%lx\n", + (int)ELF64_R_TYPE(rel[i].r_info), value); + return -ENOEXEC; +} diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 8e80901e466..84f09e9eca2 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -10,6 +10,7 @@ #include #include #include +#include #include /* Verify architecture specific macros are defined */ @@ -95,6 +96,27 @@ struct compat_kexec_segment { }; #endif +struct kexec_sha_region { + unsigned long start; + unsigned long len; +}; + +struct purgatory_info { + /* Pointer to elf header of read only purgatory */ + Elf_Ehdr *ehdr; + + /* Pointer to purgatory sechdrs which are modifiable */ + Elf_Shdr *sechdrs; + /* + * Temporary buffer location where purgatory is loaded and relocated + * This memory can be freed post image load + */ + void *purgatory_buf; + + /* Address where purgatory is finally loaded and is executed from */ + unsigned long purgatory_load_addr; +}; + struct kimage { kimage_entry_t head; kimage_entry_t *entry; @@ -143,6 +165,9 @@ struct kimage { /* Image loader handling the kernel can store a pointer here */ void *image_loader_data; + + /* Information for loading purgatory */ + struct purgatory_info purgatory_info; }; /* @@ -189,6 +214,14 @@ extern int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long *load_addr); extern struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order); +extern int kexec_load_purgatory(struct kimage *image, unsigned long min, + unsigned long max, int top_down, + unsigned long *load_addr); +extern int kexec_purgatory_get_set_symbol(struct kimage *image, + const char *name, void *buf, + unsigned int size, bool get_value); +extern void *kexec_purgatory_get_symbol_addr(struct kimage *image, + const char *name); extern void crash_kexec(struct pt_regs *); int kexec_should_crash(struct task_struct *); void crash_save_cpu(struct pt_regs *regs, int cpu); diff --git a/kernel/kexec.c b/kernel/kexec.c index 9b46219254d..669e331aa9e 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -42,6 +42,9 @@ #include #include +#include +#include + /* Per cpu memory for storing cpu states in case of system crash. */ note_buf_t __percpu *crash_notes; @@ -54,6 +57,15 @@ size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data); /* Flag to indicate we are going to kexec a new kernel */ bool kexec_in_progress = false; +/* + * Declare these symbols weak so that if architecture provides a purgatory, + * these will be overridden. + */ +char __weak kexec_purgatory[0]; +size_t __weak kexec_purgatory_size = 0; + +static int kexec_calculate_store_digests(struct kimage *image); + /* Location of the reserved area for the crash kernel */ struct resource crashk_res = { .name = "Crash kernel", @@ -404,6 +416,24 @@ void __weak arch_kimage_file_post_load_cleanup(struct kimage *image) { } +/* Apply relocations of type RELA */ +int __weak +arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, + unsigned int relsec) +{ + pr_err("RELA relocation unsupported.\n"); + return -ENOEXEC; +} + +/* Apply relocations of type REL */ +int __weak +arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, + unsigned int relsec) +{ + pr_err("REL relocation unsupported.\n"); + return -ENOEXEC; +} + /* * Free up memory used by kernel, initrd, and comand line. This is temporary * memory allocation which is not needed any more after these buffers have @@ -411,6 +441,8 @@ void __weak arch_kimage_file_post_load_cleanup(struct kimage *image) */ static void kimage_file_post_load_cleanup(struct kimage *image) { + struct purgatory_info *pi = &image->purgatory_info; + vfree(image->kernel_buf); image->kernel_buf = NULL; @@ -420,6 +452,12 @@ static void kimage_file_post_load_cleanup(struct kimage *image) kfree(image->cmdline_buf); image->cmdline_buf = NULL; + vfree(pi->purgatory_buf); + pi->purgatory_buf = NULL; + + vfree(pi->sechdrs); + pi->sechdrs = NULL; + /* See if architecture has anything to cleanup post load */ arch_kimage_file_post_load_cleanup(image); } @@ -1105,7 +1143,7 @@ static int kimage_load_crash_segment(struct kimage *image, } ubytes -= uchunk; maddr += mchunk; - buf += mchunk; + buf += mchunk; mbytes -= mchunk; } out: @@ -1340,6 +1378,10 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, if (ret) goto out; + ret = kexec_calculate_store_digests(image); + if (ret) + goto out; + for (i = 0; i < image->nr_segments; i++) { struct kexec_segment *ksegment; @@ -2092,6 +2134,506 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, return 0; } +/* Calculate and store the digest of segments */ +static int kexec_calculate_store_digests(struct kimage *image) +{ + struct crypto_shash *tfm; + struct shash_desc *desc; + int ret = 0, i, j, zero_buf_sz, sha_region_sz; + size_t desc_size, nullsz; + char *digest; + void *zero_buf; + struct kexec_sha_region *sha_regions; + struct purgatory_info *pi = &image->purgatory_info; + + zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT); + zero_buf_sz = PAGE_SIZE; + + tfm = crypto_alloc_shash("sha256", 0, 0); + if (IS_ERR(tfm)) { + ret = PTR_ERR(tfm); + goto out; + } + + desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); + desc = kzalloc(desc_size, GFP_KERNEL); + if (!desc) { + ret = -ENOMEM; + goto out_free_tfm; + } + + sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region); + sha_regions = vzalloc(sha_region_sz); + if (!sha_regions) + goto out_free_desc; + + desc->tfm = tfm; + desc->flags = 0; + + ret = crypto_shash_init(desc); + if (ret < 0) + goto out_free_sha_regions; + + digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); + if (!digest) { + ret = -ENOMEM; + goto out_free_sha_regions; + } + + for (j = i = 0; i < image->nr_segments; i++) { + struct kexec_segment *ksegment; + + ksegment = &image->segment[i]; + /* + * Skip purgatory as it will be modified once we put digest + * info in purgatory. + */ + if (ksegment->kbuf == pi->purgatory_buf) + continue; + + ret = crypto_shash_update(desc, ksegment->kbuf, + ksegment->bufsz); + if (ret) + break; + + /* + * Assume rest of the buffer is filled with zero and + * update digest accordingly. + */ + nullsz = ksegment->memsz - ksegment->bufsz; + while (nullsz) { + unsigned long bytes = nullsz; + + if (bytes > zero_buf_sz) + bytes = zero_buf_sz; + ret = crypto_shash_update(desc, zero_buf, bytes); + if (ret) + break; + nullsz -= bytes; + } + + if (ret) + break; + + sha_regions[j].start = ksegment->mem; + sha_regions[j].len = ksegment->memsz; + j++; + } + + if (!ret) { + ret = crypto_shash_final(desc, digest); + if (ret) + goto out_free_digest; + ret = kexec_purgatory_get_set_symbol(image, "sha_regions", + sha_regions, sha_region_sz, 0); + if (ret) + goto out_free_digest; + + ret = kexec_purgatory_get_set_symbol(image, "sha256_digest", + digest, SHA256_DIGEST_SIZE, 0); + if (ret) + goto out_free_digest; + } + +out_free_digest: + kfree(digest); +out_free_sha_regions: + vfree(sha_regions); +out_free_desc: + kfree(desc); +out_free_tfm: + kfree(tfm); +out: + return ret; +} + +/* Actually load purgatory. Lot of code taken from kexec-tools */ +static int __kexec_load_purgatory(struct kimage *image, unsigned long min, + unsigned long max, int top_down) +{ + struct purgatory_info *pi = &image->purgatory_info; + unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad; + unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset; + unsigned char *buf_addr, *src; + int i, ret = 0, entry_sidx = -1; + const Elf_Shdr *sechdrs_c; + Elf_Shdr *sechdrs = NULL; + void *purgatory_buf = NULL; + + /* + * sechdrs_c points to section headers in purgatory and are read + * only. No modifications allowed. + */ + sechdrs_c = (void *)pi->ehdr + pi->ehdr->e_shoff; + + /* + * We can not modify sechdrs_c[] and its fields. It is read only. + * Copy it over to a local copy where one can store some temporary + * data and free it at the end. We need to modify ->sh_addr and + * ->sh_offset fields to keep track of permanent and temporary + * locations of sections. + */ + sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr)); + if (!sechdrs) + return -ENOMEM; + + memcpy(sechdrs, sechdrs_c, pi->ehdr->e_shnum * sizeof(Elf_Shdr)); + + /* + * We seem to have multiple copies of sections. First copy is which + * is embedded in kernel in read only section. Some of these sections + * will be copied to a temporary buffer and relocated. And these + * sections will finally be copied to their final destination at + * segment load time. + * + * Use ->sh_offset to reflect section address in memory. It will + * point to original read only copy if section is not allocatable. + * Otherwise it will point to temporary copy which will be relocated. + * + * Use ->sh_addr to contain final address of the section where it + * will go during execution time. + */ + for (i = 0; i < pi->ehdr->e_shnum; i++) { + if (sechdrs[i].sh_type == SHT_NOBITS) + continue; + + sechdrs[i].sh_offset = (unsigned long)pi->ehdr + + sechdrs[i].sh_offset; + } + + /* + * Identify entry point section and make entry relative to section + * start. + */ + entry = pi->ehdr->e_entry; + for (i = 0; i < pi->ehdr->e_shnum; i++) { + if (!(sechdrs[i].sh_flags & SHF_ALLOC)) + continue; + + if (!(sechdrs[i].sh_flags & SHF_EXECINSTR)) + continue; + + /* Make entry section relative */ + if (sechdrs[i].sh_addr <= pi->ehdr->e_entry && + ((sechdrs[i].sh_addr + sechdrs[i].sh_size) > + pi->ehdr->e_entry)) { + entry_sidx = i; + entry -= sechdrs[i].sh_addr; + break; + } + } + + /* Determine how much memory is needed to load relocatable object. */ + buf_align = 1; + bss_align = 1; + buf_sz = 0; + bss_sz = 0; + + for (i = 0; i < pi->ehdr->e_shnum; i++) { + if (!(sechdrs[i].sh_flags & SHF_ALLOC)) + continue; + + align = sechdrs[i].sh_addralign; + if (sechdrs[i].sh_type != SHT_NOBITS) { + if (buf_align < align) + buf_align = align; + buf_sz = ALIGN(buf_sz, align); + buf_sz += sechdrs[i].sh_size; + } else { + /* bss section */ + if (bss_align < align) + bss_align = align; + bss_sz = ALIGN(bss_sz, align); + bss_sz += sechdrs[i].sh_size; + } + } + + /* Determine the bss padding required to align bss properly */ + bss_pad = 0; + if (buf_sz & (bss_align - 1)) + bss_pad = bss_align - (buf_sz & (bss_align - 1)); + + memsz = buf_sz + bss_pad + bss_sz; + + /* Allocate buffer for purgatory */ + purgatory_buf = vzalloc(buf_sz); + if (!purgatory_buf) { + ret = -ENOMEM; + goto out; + } + + if (buf_align < bss_align) + buf_align = bss_align; + + /* Add buffer to segment list */ + ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz, + buf_align, min, max, top_down, + &pi->purgatory_load_addr); + if (ret) + goto out; + + /* Load SHF_ALLOC sections */ + buf_addr = purgatory_buf; + load_addr = curr_load_addr = pi->purgatory_load_addr; + bss_addr = load_addr + buf_sz + bss_pad; + + for (i = 0; i < pi->ehdr->e_shnum; i++) { + if (!(sechdrs[i].sh_flags & SHF_ALLOC)) + continue; + + align = sechdrs[i].sh_addralign; + if (sechdrs[i].sh_type != SHT_NOBITS) { + curr_load_addr = ALIGN(curr_load_addr, align); + offset = curr_load_addr - load_addr; + /* We already modifed ->sh_offset to keep src addr */ + src = (char *) sechdrs[i].sh_offset; + memcpy(buf_addr + offset, src, sechdrs[i].sh_size); + + /* Store load address and source address of section */ + sechdrs[i].sh_addr = curr_load_addr; + + /* + * This section got copied to temporary buffer. Update + * ->sh_offset accordingly. + */ + sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset); + + /* Advance to the next address */ + curr_load_addr += sechdrs[i].sh_size; + } else { + bss_addr = ALIGN(bss_addr, align); + sechdrs[i].sh_addr = bss_addr; + bss_addr += sechdrs[i].sh_size; + } + } + + /* Update entry point based on load address of text section */ + if (entry_sidx >= 0) + entry += sechdrs[entry_sidx].sh_addr; + + /* Make kernel jump to purgatory after shutdown */ + image->start = entry; + + /* Used later to get/set symbol values */ + pi->sechdrs = sechdrs; + + /* + * Used later to identify which section is purgatory and skip it + * from checksumming. + */ + pi->purgatory_buf = purgatory_buf; + return ret; +out: + vfree(sechdrs); + vfree(purgatory_buf); + return ret; +} + +static int kexec_apply_relocations(struct kimage *image) +{ + int i, ret; + struct purgatory_info *pi = &image->purgatory_info; + Elf_Shdr *sechdrs = pi->sechdrs; + + /* Apply relocations */ + for (i = 0; i < pi->ehdr->e_shnum; i++) { + Elf_Shdr *section, *symtab; + + if (sechdrs[i].sh_type != SHT_RELA && + sechdrs[i].sh_type != SHT_REL) + continue; + + /* + * For section of type SHT_RELA/SHT_REL, + * ->sh_link contains section header index of associated + * symbol table. And ->sh_info contains section header + * index of section to which relocations apply. + */ + if (sechdrs[i].sh_info >= pi->ehdr->e_shnum || + sechdrs[i].sh_link >= pi->ehdr->e_shnum) + return -ENOEXEC; + + section = &sechdrs[sechdrs[i].sh_info]; + symtab = &sechdrs[sechdrs[i].sh_link]; + + if (!(section->sh_flags & SHF_ALLOC)) + continue; + + /* + * symtab->sh_link contain section header index of associated + * string table. + */ + if (symtab->sh_link >= pi->ehdr->e_shnum) + /* Invalid section number? */ + continue; + + /* + * Respective archicture needs to provide support for applying + * relocations of type SHT_RELA/SHT_REL. + */ + if (sechdrs[i].sh_type == SHT_RELA) + ret = arch_kexec_apply_relocations_add(pi->ehdr, + sechdrs, i); + else if (sechdrs[i].sh_type == SHT_REL) + ret = arch_kexec_apply_relocations(pi->ehdr, + sechdrs, i); + if (ret) + return ret; + } + + return 0; +} + +/* Load relocatable purgatory object and relocate it appropriately */ +int kexec_load_purgatory(struct kimage *image, unsigned long min, + unsigned long max, int top_down, + unsigned long *load_addr) +{ + struct purgatory_info *pi = &image->purgatory_info; + int ret; + + if (kexec_purgatory_size <= 0) + return -EINVAL; + + if (kexec_purgatory_size < sizeof(Elf_Ehdr)) + return -ENOEXEC; + + pi->ehdr = (Elf_Ehdr *)kexec_purgatory; + + if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0 + || pi->ehdr->e_type != ET_REL + || !elf_check_arch(pi->ehdr) + || pi->ehdr->e_shentsize != sizeof(Elf_Shdr)) + return -ENOEXEC; + + if (pi->ehdr->e_shoff >= kexec_purgatory_size + || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) > + kexec_purgatory_size - pi->ehdr->e_shoff)) + return -ENOEXEC; + + ret = __kexec_load_purgatory(image, min, max, top_down); + if (ret) + return ret; + + ret = kexec_apply_relocations(image); + if (ret) + goto out; + + *load_addr = pi->purgatory_load_addr; + return 0; +out: + vfree(pi->sechdrs); + vfree(pi->purgatory_buf); + return ret; +} + +static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, + const char *name) +{ + Elf_Sym *syms; + Elf_Shdr *sechdrs; + Elf_Ehdr *ehdr; + int i, k; + const char *strtab; + + if (!pi->sechdrs || !pi->ehdr) + return NULL; + + sechdrs = pi->sechdrs; + ehdr = pi->ehdr; + + for (i = 0; i < ehdr->e_shnum; i++) { + if (sechdrs[i].sh_type != SHT_SYMTAB) + continue; + + if (sechdrs[i].sh_link >= ehdr->e_shnum) + /* Invalid strtab section number */ + continue; + strtab = (char *)sechdrs[sechdrs[i].sh_link].sh_offset; + syms = (Elf_Sym *)sechdrs[i].sh_offset; + + /* Go through symbols for a match */ + for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) { + if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL) + continue; + + if (strcmp(strtab + syms[k].st_name, name) != 0) + continue; + + if (syms[k].st_shndx == SHN_UNDEF || + syms[k].st_shndx >= ehdr->e_shnum) { + pr_debug("Symbol: %s has bad section index %d.\n", + name, syms[k].st_shndx); + return NULL; + } + + /* Found the symbol we are looking for */ + return &syms[k]; + } + } + + return NULL; +} + +void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name) +{ + struct purgatory_info *pi = &image->purgatory_info; + Elf_Sym *sym; + Elf_Shdr *sechdr; + + sym = kexec_purgatory_find_symbol(pi, name); + if (!sym) + return ERR_PTR(-EINVAL); + + sechdr = &pi->sechdrs[sym->st_shndx]; + + /* + * Returns the address where symbol will finally be loaded after + * kexec_load_segment() + */ + return (void *)(sechdr->sh_addr + sym->st_value); +} + +/* + * Get or set value of a symbol. If "get_value" is true, symbol value is + * returned in buf otherwise symbol value is set based on value in buf. + */ +int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, + void *buf, unsigned int size, bool get_value) +{ + Elf_Sym *sym; + Elf_Shdr *sechdrs; + struct purgatory_info *pi = &image->purgatory_info; + char *sym_buf; + + sym = kexec_purgatory_find_symbol(pi, name); + if (!sym) + return -EINVAL; + + if (sym->st_size != size) { + pr_err("symbol %s size mismatch: expected %lu actual %u\n", + name, (unsigned long)sym->st_size, size); + return -EINVAL; + } + + sechdrs = pi->sechdrs; + + if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { + pr_err("symbol %s is in a bss section. Cannot %s\n", name, + get_value ? "get" : "set"); + return -EINVAL; + } + + sym_buf = (unsigned char *)sechdrs[sym->st_shndx].sh_offset + + sym->st_value; + + if (get_value) + memcpy((void *)buf, sym_buf, size); + else + memcpy((void *)sym_buf, buf, size); + + return 0; +} /* * Move into place and start executing a preloaded standalone -- cgit v1.2.3-70-g09d2