diff options
| -rw-r--r-- | arch/x86/entry/vsyscall/vsyscall_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/mmu.h | 9 | ||||
| -rw-r--r-- | arch/x86/include/asm/mmu_context.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 17 |
4 files changed, 20 insertions, 10 deletions
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c index 44c33103a955..1b40b9297083 100644 --- a/arch/x86/entry/vsyscall/vsyscall_64.c +++ b/arch/x86/entry/vsyscall/vsyscall_64.c @@ -316,7 +316,7 @@ static struct vm_area_struct gate_vma __ro_after_init = { struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { #ifdef CONFIG_COMPAT - if (!mm || mm->context.ia32_compat) + if (!mm || !(mm->context.flags & MM_CONTEXT_HAS_VSYSCALL)) return NULL; #endif if (vsyscall_mode == NONE) diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h index 9257667d13c5..5d7494631ea9 100644 --- a/arch/x86/include/asm/mmu.h +++ b/arch/x86/include/asm/mmu.h @@ -6,6 +6,12 @@ #include <linux/rwsem.h> #include <linux/mutex.h> #include <linux/atomic.h> +#include <linux/bits.h> + +/* Uprobes on this MM assume 32-bit code */ +#define MM_CONTEXT_UPROBE_IA32 BIT(0) +/* vsyscall page is accessible on this MM */ +#define MM_CONTEXT_HAS_VSYSCALL BIT(1) /* * x86 has arch-specific MMU state beyond what lives in mm_struct. @@ -33,8 +39,7 @@ typedef struct { #endif #ifdef CONFIG_X86_64 - /* True if mm supports a task running in 32 bit compatibility mode. */ - unsigned short ia32_compat; + unsigned short flags; #endif struct mutex lock; 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) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 5fb4103101f5..d6efaf6623c9 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -646,10 +646,8 @@ void set_personality_64bit(void) /* Pretend that this comes from a 64bit execve */ task_pt_regs(current)->orig_ax = __NR_execve; current_thread_info()->status &= ~TS_COMPAT; - - /* Ensure the corresponding mm is not marked. */ if (current->mm) - current->mm->context.ia32_compat = 0; + current->mm->context.flags = MM_CONTEXT_HAS_VSYSCALL; /* TBD: overwrites user setup. Should have two bits. But 64bit processes have always behaved this way, @@ -664,7 +662,8 @@ static void __set_personality_x32(void) clear_thread_flag(TIF_IA32); set_thread_flag(TIF_X32); if (current->mm) - current->mm->context.ia32_compat = TIF_X32; + current->mm->context.flags = 0; + current->personality &= ~READ_IMPLIES_EXEC; /* * in_32bit_syscall() uses the presence of the x32 syscall bit @@ -684,8 +683,14 @@ static void __set_personality_ia32(void) #ifdef CONFIG_IA32_EMULATION set_thread_flag(TIF_IA32); clear_thread_flag(TIF_X32); - if (current->mm) - current->mm->context.ia32_compat = TIF_IA32; + if (current->mm) { + /* + * uprobes applied to this MM need to know this and + * cannot use user_64bit_mode() at that time. + */ + current->mm->context.flags = MM_CONTEXT_UPROBE_IA32; + } + current->personality |= force_personality32; /* Prepare the first "return" to user space */ task_pt_regs(current)->orig_ax = __NR_ia32_execve; |