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authorYury Norov <ynorov@caviumnetworks.com>2017-08-20 13:20:47 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2017-08-22 18:13:04 +0100
commit5ce93ab624cee4ed68086c946bd6d18b9b3f64aa (patch)
tree189c30a3a1e8ea8483aa8cc22a478ad0a6093e05
parent828f193dd62a40ade5ea8b24cb8b0a22c30df673 (diff)
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 <ynorov@caviumnetworks.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/include/asm/elf.h4
-rw-r--r--arch/arm64/include/asm/mmu.h2
-rw-r--r--arch/arm64/kernel/probes/uprobes.c2
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, &current->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, &current->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;