diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index a4b233a0659e..b06a758abb63 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -28,6 +28,7 @@ config RISCV select ARCH_HAS_DEBUG_VIRTUAL if MMU select ARCH_HAS_DEBUG_VM_PGTABLE select ARCH_HAS_DEBUG_WX + select ARCH_HAS_ELF_CORE_EFLAGS select ARCH_HAS_FAST_MULTIPLIER select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt index bd2f530e5740..1949e25c7741 100644 --- a/fs/Kconfig.binfmt +++ b/fs/Kconfig.binfmt @@ -184,4 +184,13 @@ config EXEC_KUNIT_TEST This builds the exec KUnit tests, which tests boundary conditions of various aspects of the exec internals. +config ARCH_HAS_ELF_CORE_EFLAGS + bool + depends on BINFMT_ELF && ELF_CORE + default n + help + Select this option if the architecture makes use of the e_flags + field in the ELF header to store ABI or other architecture-specific + information that should be preserved in core dumps. + endmenu diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 4aacf9c9cc2d..e4653bb99946 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -103,6 +103,21 @@ static struct linux_binfmt elf_format = { #define BAD_ADDR(x) (unlikely((unsigned long)(x) >= TASK_SIZE)) +static inline void elf_coredump_set_mm_eflags(struct mm_struct *mm, u32 flags) +{ +#ifdef CONFIG_ARCH_HAS_ELF_CORE_EFLAGS + mm->saved_e_flags = flags; +#endif +} + +static inline u32 elf_coredump_get_mm_eflags(struct mm_struct *mm, u32 flags) +{ +#ifdef CONFIG_ARCH_HAS_ELF_CORE_EFLAGS + flags = mm->saved_e_flags; +#endif + return flags; +} + /* * We need to explicitly zero any trailing portion of the page that follows * p_filesz when it ends before the page ends (e.g. bss), otherwise this @@ -1290,6 +1305,8 @@ static int load_elf_binary(struct linux_binprm *bprm) mm->end_data = end_data; mm->start_stack = bprm->p; + elf_coredump_set_mm_eflags(mm, elf_ex->e_flags); + /** * DOC: "brk" handling * @@ -1804,6 +1821,8 @@ static int fill_note_info(struct elfhdr *elf, int phdrs, struct elf_thread_core_info *t; struct elf_prpsinfo *psinfo; struct core_thread *ct; + u16 machine; + u32 flags; psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); if (!psinfo) @@ -1831,17 +1850,26 @@ static int fill_note_info(struct elfhdr *elf, int phdrs, return 0; } - /* - * Initialize the ELF file header. - */ - fill_elf_header(elf, phdrs, - view->e_machine, view->e_flags); + machine = view->e_machine; + flags = view->e_flags; #else view = NULL; info->thread_notes = 2; - fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS); + machine = ELF_ARCH; + flags = ELF_CORE_EFLAGS; #endif + /* + * Override ELF e_flags with value taken from process, + * if arch needs that. + */ + flags = elf_coredump_get_mm_eflags(dump_task->mm, flags); + + /* + * Initialize the ELF file header. + */ + fill_elf_header(elf, phdrs, machine, flags); + /* * Allocate a structure for each thread. */ diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 08bc2442db93..04a2857f12f2 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -1102,6 +1102,11 @@ struct mm_struct { unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ +#ifdef CONFIG_ARCH_HAS_ELF_CORE_EFLAGS + /* the ABI-related flags from the ELF header. Used for core dump */ + unsigned long saved_e_flags; +#endif + struct percpu_counter rss_stat[NR_MM_COUNTERS]; struct linux_binfmt *binfmt;