| Message ID | 20170805144022.17260-2-ynorov@caviumnetworks.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Aug 05, 2017 at 05:40:21PM +0300, Yury Norov wrote: > diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h > index 5468c834b072..2c57b06b2883 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 0x0 /* MM hosts AArch32 executables */ Nitpick: drop 0x since it's a bit number not a flag value. We could, however, make it a value and just stop using (set|clear)_bit functions. There is no atomicity issue here.
diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index acae781f7359..de11ed1484e3 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); \ + clear_bit(MMCF_AARCH32, ¤t->mm->context.flags); \ 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); \ + set_bit(MMCF_AARCH32, ¤t->mm->context.flags); \ 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..2c57b06b2883 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 0x0 /* MM hosts 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..f29ef6b297e4 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 (test_bit(MMCF_AARCH32, &mm->context.flags)) return -ENOTSUPP; else if (!IS_ALIGNED(addr, AARCH64_INSN_SIZE)) return -EINVAL;
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. RFC: https://lkml.org/lkml/2017/7/31/454 v1: - changed the MMCF_AARCH32 bit number from 0x1 to 0x0 and added comment. Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> CC: Pratyush Anand <panand@redhat.com> CC: Catalin Marinas <catalin.marinas@arm.com> --- 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(-)