From 5ce93ab624cee4ed68086c946bd6d18b9b3f64aa Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 20 Aug 2017 13:20:47 +0300 Subject: [PATCH] arm64: introduce separated bits for mm_context_t flags Currently mm->context.flags field uses thread_info flags which is not the best idea for many reasons. For example, mm_context_t doesn't need most of thread_info flags. And it would be difficult to add new mm-related flag if needed because it may easily interfere with TIF ones. To deal with it, the new MMCF_AARCH32 flag is introduced for mm_context_t->flags, where MMCF prefix stands for mm_context_t flags. Also, mm_context_t flag doesn't require atomicity and ordering of the access, so using set/clear_bit() is replaced with simple masks. Signed-off-by: Yury Norov Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/elf.h | 4 ++-- arch/arm64/include/asm/mmu.h | 2 ++ arch/arm64/kernel/probes/uprobes.c | 2 +- 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index acae781f7359..f4e33f8356ca 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -139,7 +139,7 @@ typedef struct user_fpsimd_state elf_fpregset_t; #define SET_PERSONALITY(ex) \ ({ \ - clear_bit(TIF_32BIT, ¤t->mm->context.flags); \ + current->mm->context.flags = 0; \ clear_thread_flag(TIF_32BIT); \ current->personality &= ~READ_IMPLIES_EXEC; \ }) @@ -195,7 +195,7 @@ typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_ELF_NGREG]; */ #define COMPAT_SET_PERSONALITY(ex) \ ({ \ - set_bit(TIF_32BIT, ¤t->mm->context.flags); \ + current->mm->context.flags = MMCF_AARCH32; \ set_thread_flag(TIF_32BIT); \ }) #define COMPAT_ARCH_DLINFO diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index 5468c834b072..0d34bf0a89c7 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -16,6 +16,8 @@ #ifndef __ASM_MMU_H #define __ASM_MMU_H +#define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */ + typedef struct { atomic64_t id; void *vdso; diff --git a/arch/arm64/kernel/probes/uprobes.c b/arch/arm64/kernel/probes/uprobes.c index 26c998534dca..636ca0119c0e 100644 --- a/arch/arm64/kernel/probes/uprobes.c +++ b/arch/arm64/kernel/probes/uprobes.c @@ -40,7 +40,7 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, probe_opcode_t insn; /* TODO: Currently we do not support AARCH32 instruction probing */ - if (test_bit(TIF_32BIT, &mm->context.flags)) + if (mm->context.flags & MMCF_AARCH32) return -ENOTSUPP; else if (!IS_ALIGNED(addr, AARCH64_INSN_SIZE)) return -EINVAL;