From 7facdc426f86c67e579e49e100943cbccc43e1c6 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 13 Jun 2020 23:03:25 -0400 Subject: [PATCH] [amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properly To get rid of hardcoded size/offset in those macros we need to have a definition of i386 variant of struct elf_prstatus. However, we can't do that in asm/compat.h - the types needed for that are not there and adding an include of asm/user32.h into asm/compat.h would cause a lot of mess. That could be conveniently done in elfcore-compat.h, but currently there is nowhere to put arch-dependent parts of it - no asm/elfcore-compat.h. So we introduce a new file (asm/elfcore-compat.h, present on architectures that have CONFIG_ARCH_HAS_ELFCORE_COMPAT set, currently only on x86), have it pulled by linux/elfcore-compat.h and move the definitions there. As a side benefit, we don't need to worry about accidental inclusion of that file into binfmt_elf.c itself, so we don't need the dance with COMPAT_PRSTATUS_SIZE, etc. - only fs/compat_binfmt_elf.c will see that header. Signed-off-by: Al Viro --- arch/Kconfig | 3 +++ arch/x86/Kconfig | 1 + arch/x86/include/asm/compat.h | 14 ------------ arch/x86/include/asm/elfcore-compat.h | 31 +++++++++++++++++++++++++++ fs/compat_binfmt_elf.c | 8 ------- include/linux/elfcore-compat.h | 18 ++++++++++------ 6 files changed, 46 insertions(+), 29 deletions(-) create mode 100644 arch/x86/include/asm/elfcore-compat.h diff --git a/arch/Kconfig b/arch/Kconfig index 78c6f05b10f9..a17ced73b23c 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1105,6 +1105,9 @@ config HAVE_ARCH_PFN_VALID config ARCH_SUPPORTS_DEBUG_PAGEALLOC bool +config ARCH_HAS_ELFCORE_COMPAT + bool + source "kernel/gcov/Kconfig" source "scripts/gcc-plugins/Kconfig" diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7b6dd10b162a..302a6b453c91 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -31,6 +31,7 @@ config X86_64 select MODULES_USE_ELF_RELA select NEED_DMA_MAP_STATE select SWIOTLB + select ARCH_HAS_ELFCORE_COMPAT config FORCE_DYNAMIC_FTRACE def_bool y diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index 15cf0f831dee..be09c7eac89f 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -159,20 +159,6 @@ struct compat_shmid64_ds { compat_ulong_t __unused5; }; -/* - * The type of struct elf_prstatus.pr_reg in compatible core dumps. - */ -typedef struct user_regs_struct compat_elf_gregset_t; - -/* Full regset -- prstatus on x32, otherwise on ia32 */ -#define COMPAT_PRSTATUS_SIZE (user_64bit_mode(task_pt_regs(current)) \ - ? sizeof(struct compat_elf_prstatus) \ - : 144) -#define COMPAT_SET_PR_FPVALID(S) \ - (*(user_64bit_mode(task_pt_regs(current)) \ - ? &(S)->pr_fpvalid \ - : (int *)((void *)(S) + 140)) = 1) - #ifdef CONFIG_X86_X32_ABI #define COMPAT_USE_64BIT_TIME \ (!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT)) diff --git a/arch/x86/include/asm/elfcore-compat.h b/arch/x86/include/asm/elfcore-compat.h new file mode 100644 index 000000000000..f1b6c7a8d8fc --- /dev/null +++ b/arch/x86/include/asm/elfcore-compat.h @@ -0,0 +1,31 @@ +#ifndef _ASM_X86_ELFCORE_COMPAT_H +#define _ASM_X86_ELFCORE_COMPAT_H + +#include + +/* + * On amd64 we have two 32bit ABIs - i386 and x32. The latter + * has bigger registers, so we use it for compat_elf_regset_t. + * The former uses i386_elf_prstatus and PRSTATUS_SIZE/SET_PR_FPVALID + * are used to choose the size and location of ->pr_fpvalid of + * the layout actually used. + */ +typedef struct user_regs_struct compat_elf_gregset_t; + +struct i386_elf_prstatus +{ + struct compat_elf_prstatus_common common; + struct user_regs_struct32 pr_reg; + compat_int_t pr_fpvalid; +}; + +#define PRSTATUS_SIZE \ + (user_64bit_mode(task_pt_regs(current)) \ + ? sizeof(struct compat_elf_prstatus) \ + : sizeof(struct i386_elf_prstatus)) +#define SET_PR_FPVALID(S) \ + (*(user_64bit_mode(task_pt_regs(current)) \ + ? &(S)->pr_fpvalid \ + : &((struct i386_elf_prstatus *)(S))->pr_fpvalid) = 1) + +#endif diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index feb48a5c2d44..a6321415aba0 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -96,14 +96,6 @@ #define ELF_EXEC_PAGESIZE COMPAT_ELF_EXEC_PAGESIZE #endif -#ifdef COMPAT_PRSTATUS_SIZE -#define PRSTATUS_SIZE COMPAT_PRSTATUS_SIZE -#endif - -#ifdef COMPAT_SET_PR_FPVALID -#define SET_PR_FPVALID(S) COMPAT_SET_PR_FPVALID(S) -#endif - #ifdef COMPAT_ELF_PLAT_INIT #undef ELF_PLAT_INIT #define ELF_PLAT_INIT COMPAT_ELF_PLAT_INIT diff --git a/include/linux/elfcore-compat.h b/include/linux/elfcore-compat.h index 4aeda5f1f038..e272c3d452ce 100644 --- a/include/linux/elfcore-compat.h +++ b/include/linux/elfcore-compat.h @@ -33,13 +33,6 @@ struct compat_elf_prstatus_common struct old_timeval32 pr_cstime; }; -struct compat_elf_prstatus -{ - struct compat_elf_prstatus_common common; - compat_elf_gregset_t pr_reg; - compat_int_t pr_fpvalid; -}; - struct compat_elf_prpsinfo { char pr_state; @@ -54,4 +47,15 @@ struct compat_elf_prpsinfo char pr_psargs[ELF_PRARGSZ]; }; +#ifdef CONFIG_ARCH_HAS_ELFCORE_COMPAT +#include +#endif + +struct compat_elf_prstatus +{ + struct compat_elf_prstatus_common common; + compat_elf_gregset_t pr_reg; + compat_int_t pr_fpvalid; +}; + #endif /* _LINUX_ELFCORE_COMPAT_H */