From ff170cd0595398a7b66cb40f249eb2f10c29b66d Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:35 -0400 Subject: x86/mm: Convert mmu context ia32_compat into a proper flags field The ia32_compat attribute is a weird thing. It mirrors TIF_IA32 and TIF_X32 and is used only in two very unrelated places: (1) to decide if the vsyscall page is accessible (2) for uprobes to find whether the patched instruction is 32 or 64 bit. In preparation to remove the TIF flags, a new mechanism is required for ia32_compat, but given its odd semantics, adding a real flags field which configures these specific behaviours is the best option. So, set_personality_x64() can ask for the vsyscall page, which is not available in x32/ia32 and set_personality_ia32() can configure the uprobe code as needed. uprobe cannot rely on other methods like user_64bit_mode() to decide how to patch, so it needs some specific flag like this. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Acked-by: Andy Lutomirski Link: https://lore.kernel.org/r/20201004032536.1229030-10-krisman@collabora.com --- arch/x86/include/asm/mmu_context.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/include/asm/mmu_context.h') diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index d98016b83755..054a79157323 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -177,7 +177,7 @@ static inline void arch_exit_mmap(struct mm_struct *mm) static inline bool is_64bit_mm(struct mm_struct *mm) { return !IS_ENABLED(CONFIG_IA32_EMULATION) || - !(mm->context.ia32_compat == TIF_IA32); + !(mm->context.flags & MM_CONTEXT_UPROBE_IA32); } #else static inline bool is_64bit_mm(struct mm_struct *mm) -- cgit v1.2.3