After finding a bug in glibc the question came up how linux/elfcore.h is supposed to be used from user space. As far as I can tell, it's not possible, as it references data types that are simply unavailable there.
The #ifndef __KERNEL__ section in that header dates back to when the file was introduced in linux-1.3.5, and presumably was meant to provide the structures for the libc sys/procfs.h implementation. However, this was never portable to architectures other than x86-32, and has been broken on that architecture at a later point. These are the steps that I needed to make it possible to include the header file, e.g. for libc self-testing in order to make sure the structures are compatible with its own: - drop the #ifndef __KERNEL__ section that are obviously useless and get in the way - change the pid_t references to __kernel_pid_t - Move required data from the private x86 asm/elf.h file into a new uapi/asm/elf.h. Some other architectures already do that, but most of them do not. Before applying the patch, we have to do this for all architectures - Change ELF_NGREG to an integer literal constant instead of a sizeof operation based on a private type. Cc: Joseph Myers <jos...@codesourcery.com> Cc: David Howells <dhowe...@redhat.com> Cc: libc-al...@sourceware.org Link: https://patchwork.ozlabs.org/patch/969540/ Signed-off-by: Arnd Bergmann <a...@arndb.de> --- arch/x86/include/asm/elf.h | 24 +----------------------- arch/x86/include/uapi/asm/elf.h | 30 ++++++++++++++++++++++++++++++ arch/x86/include/uapi/asm/signal.h | 2 +- include/uapi/linux/elf.h | 1 + include/uapi/linux/elfcore.h | 26 +++++--------------------- 5 files changed, 38 insertions(+), 45 deletions(-) create mode 100644 arch/x86/include/uapi/asm/elf.h diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 0d157d2a1e2a..973bd7b5b164 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -10,18 +10,10 @@ #include <asm/ptrace.h> #include <asm/user.h> #include <asm/auxvec.h> - -typedef unsigned long elf_greg_t; - -#define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t)) -typedef elf_greg_t elf_gregset_t[ELF_NGREG]; - -typedef struct user_i387_struct elf_fpregset_t; +#include <uapi/asm/elf.h> #ifdef __i386__ -typedef struct user_fxsr_struct elf_fpxregset_t; - #define R_386_NONE 0 #define R_386_32 1 #define R_386_PC32 2 @@ -35,13 +27,6 @@ typedef struct user_fxsr_struct elf_fpxregset_t; #define R_386_GOTPC 10 #define R_386_NUM 11 -/* - * These are used to set parameters in the core dumps. - */ -#define ELF_CLASS ELFCLASS32 -#define ELF_DATA ELFDATA2LSB -#define ELF_ARCH EM_386 - #else /* x86-64 relocation types */ @@ -65,13 +50,6 @@ typedef struct user_fxsr_struct elf_fpxregset_t; #define R_X86_64_NUM 16 -/* - * These are used to set parameters in the core dumps. - */ -#define ELF_CLASS ELFCLASS64 -#define ELF_DATA ELFDATA2LSB -#define ELF_ARCH EM_X86_64 - #endif #include <asm/vdso.h> diff --git a/arch/x86/include/uapi/asm/elf.h b/arch/x86/include/uapi/asm/elf.h new file mode 100644 index 000000000000..a640e1224939 --- /dev/null +++ b/arch/x86/include/uapi/asm/elf.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _UAPI_ASM_X86_ELF_H +#define _UAPI_ASM_X86_ELF_H + +#ifdef __i386__ + +/* + * These are used to set parameters in the core dumps. + */ +#define ELF_CLASS ELFCLASS32 +#define ELF_DATA ELFDATA2LSB +#define ELF_ARCH EM_386 +#define ELF_NGREG 17 + +#else + +/* + * These are used to set parameters in the core dumps. + */ +#define ELF_CLASS ELFCLASS64 +#define ELF_DATA ELFDATA2LSB +#define ELF_ARCH EM_X86_64 +#define ELF_NGREG 27 + +#endif /* __i386__ */ + +typedef unsigned long elf_greg_t; +typedef elf_greg_t elf_gregset_t[ELF_NGREG]; + +#endif diff --git a/arch/x86/include/uapi/asm/signal.h b/arch/x86/include/uapi/asm/signal.h index e5745d593dc7..00f273eaddf7 100644 --- a/arch/x86/include/uapi/asm/signal.h +++ b/arch/x86/include/uapi/asm/signal.h @@ -128,7 +128,7 @@ struct sigaction { typedef struct sigaltstack { void __user *ss_sp; int ss_flags; - size_t ss_size; + __kernel_size_t ss_size; } stack_t; #endif /* __ASSEMBLY__ */ diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index c5358e0ae7c5..e1e4561ed9c2 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -4,6 +4,7 @@ #include <linux/types.h> #include <linux/elf-em.h> +#include <asm/elf.h> /* 32-bit ELF base types. */ typedef __u32 Elf32_Addr; diff --git a/include/uapi/linux/elfcore.h b/include/uapi/linux/elfcore.h index baf03562306d..9c0078004275 100644 --- a/include/uapi/linux/elfcore.h +++ b/include/uapi/linux/elfcore.h @@ -16,15 +16,6 @@ struct elf_siginfo int si_errno; /* errno */ }; - -#ifndef __KERNEL__ -typedef elf_greg_t greg_t; -typedef elf_gregset_t gregset_t; -typedef elf_fpregset_t fpregset_t; -typedef elf_fpxregset_t fpxregset_t; -#define NGREG ELF_NGREG -#endif - /* * Definitions to generate Intel SVR4-like core files. * These mostly have the same names as the SVR4 types with "elf_" @@ -49,10 +40,10 @@ struct elf_prstatus struct sigaltstack pr_altstack; /* Alternate stack info */ struct sigaction pr_action; /* Signal action for current sig */ #endif - pid_t pr_pid; - pid_t pr_ppid; - pid_t pr_pgrp; - pid_t pr_sid; + __kernel_pid_t pr_pid; + __kernel_pid_t pr_ppid; + __kernel_pid_t pr_pgrp; + __kernel_pid_t pr_sid; struct __kernel_old_timeval pr_utime; /* User time */ struct __kernel_old_timeval pr_stime; /* System time */ struct __kernel_old_timeval pr_cutime; /* Cumulative user time */ @@ -85,17 +76,10 @@ struct elf_prpsinfo unsigned long pr_flag; /* flags */ __kernel_uid_t pr_uid; __kernel_gid_t pr_gid; - pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid; + __kernel_pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid; /* Lots missing */ char pr_fname[16]; /* filename of executable */ char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */ }; -#ifndef __KERNEL__ -typedef struct elf_prstatus prstatus_t; -typedef struct elf_prpsinfo prpsinfo_t; -#define PRARGSZ ELF_PRARGSZ -#endif - - #endif /* _UAPI_LINUX_ELFCORE_H */ -- 2.18.0
