From 375d4bfda57392f0865dae051e1c4bd2700e8d71 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:27 -0400 Subject: [PATCH 01/11] perf/x86: Avoid TIF_IA32 when checking 64bit mode In preparation to remove TIF_IA32, stop using it in perf events code. Tested by running perf on 32-bit, 64-bit and x32 applications. Suggested-by: Andy Lutomirski Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20201004032536.1229030-2-krisman@collabora.com --- arch/x86/events/core.c | 2 +- arch/x86/events/intel/ds.c | 2 +- arch/x86/events/intel/lbr.c | 2 +- arch/x86/kernel/perf_regs.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index a88c94d65693..77b963e5e70a 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2602,7 +2602,7 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *ent struct stack_frame_ia32 frame; const struct stack_frame_ia32 __user *fp; - if (!test_thread_flag(TIF_IA32)) + if (user_64bit_mode(regs)) return 0; cs_base = get_segment_base(regs->cs); diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index 404315df1e16..99a59f38a4e2 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1259,7 +1259,7 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs) old_to = to; #ifdef CONFIG_X86_64 - is_64bit = kernel_ip(to) || !test_thread_flag(TIF_IA32); + is_64bit = kernel_ip(to) || any_64bit_mode(regs); #endif insn_init(&insn, kaddr, size, is_64bit); insn_get_length(&insn); diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 8961653c5dd2..1aadb253d296 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -1221,7 +1221,7 @@ static int branch_type(unsigned long from, unsigned long to, int abort) * on 64-bit systems running 32-bit apps */ #ifdef CONFIG_X86_64 - is64 = kernel_ip((unsigned long)addr) || !test_thread_flag(TIF_IA32); + is64 = kernel_ip((unsigned long)addr) || any_64bit_mode(current_pt_regs()); #endif insn_init(&insn, addr, bytes_read, is64); insn_get_opcode(&insn); diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c index bb7e1132290b..9332c49a64a8 100644 --- a/arch/x86/kernel/perf_regs.c +++ b/arch/x86/kernel/perf_regs.c @@ -123,7 +123,7 @@ int perf_reg_validate(u64 mask) u64 perf_reg_abi(struct task_struct *task) { - if (test_tsk_thread_flag(task, TIF_IA32)) + if (!user_64bit_mode(task_pt_regs(task))) return PERF_SAMPLE_REGS_ABI_32; else return PERF_SAMPLE_REGS_ABI_64; From 214f0e804358cdd13b5cbe4445189f23e30618b4 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:28 -0400 Subject: [PATCH 02/11] x86/compat: Simplify compat syscall userspace allocation When allocating user memory space for a compat system call, don't consider whether the originating code is IA32 or X32, just allocate from a safe region for both, beyond the redzone. This should be safe for IA32, and has the benefit of avoiding TIF_IA32, which is about to be removed. Suggested-by: Andy Lutomirski Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201004032536.1229030-3-krisman@collabora.com --- arch/x86/include/asm/compat.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index 0e327a01f50f..f145e3326c6d 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -177,14 +177,13 @@ typedef struct user_regs_struct compat_elf_gregset_t; static inline void __user *arch_compat_alloc_user_space(long len) { - compat_uptr_t sp; + compat_uptr_t sp = task_pt_regs(current)->sp; - if (test_thread_flag(TIF_IA32)) { - sp = task_pt_regs(current)->sp; - } else { - /* -128 for the x32 ABI redzone */ - sp = task_pt_regs(current)->sp - 128; - } + /* + * -128 for the x32 ABI redzone. For IA32, it is not strictly + * necessary, but not harmful. + */ + sp -= 128; return (void __user *)round_down(sp - len, 16); } From 47cd4dac1fb21759ffcfe0600827c87fa6acdfa7 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:29 -0400 Subject: [PATCH 03/11] x86/oprofile: Avoid TIF_IA32 when checking 64bit mode In preparation to remove TIF_IA32, stop using it in oprofile code. Use user_64bit_mode() instead. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201004032536.1229030-4-krisman@collabora.com --- arch/x86/oprofile/backtrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c index a2488b6e27d6..1d8391fcca68 100644 --- a/arch/x86/oprofile/backtrace.c +++ b/arch/x86/oprofile/backtrace.c @@ -49,7 +49,7 @@ x86_backtrace_32(struct pt_regs * const regs, unsigned int depth) struct stack_frame_ia32 *head; /* User process is IA32 */ - if (!current || !test_thread_flag(TIF_IA32)) + if (!current || user_64bit_mode(regs)) return 0; head = (struct stack_frame_ia32 *) regs->bp; From 2656af0d5abfa26d7f1e40f92e9953fe155b950a Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:30 -0400 Subject: [PATCH 04/11] x86/elf: Use e_machine to choose DLINFO in compat Since TIF_X32 is going away, avoid using it to find the ELF type on ARCH_DLINFO. According to SysV AMD64 ABI Draft, an AMD64 ELF object using ILP32 must have ELFCLASS32 with (E_MACHINE == EM_X86_64), so use that ELF field to differentiate a x32 object from a IA32 object when loading ARCH_DLINFO in compat mode. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Reviewed-by: Andy Lutomirski Link: https://lore.kernel.org/r/20201004032536.1229030-5-krisman@collabora.com --- arch/x86/include/asm/elf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index b9a5d488f1a5..9220efc65d78 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -361,7 +361,7 @@ do { \ #define AT_SYSINFO 32 #define COMPAT_ARCH_DLINFO \ -if (test_thread_flag(TIF_X32)) \ +if (exec->e_machine == EM_X86_64) \ ARCH_DLINFO_X32; \ else \ ARCH_DLINFO_IA32 From bc3d7bf61a9eaecccc84dc2ecc2a9a3fa4f5ec47 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:31 -0400 Subject: [PATCH 05/11] elf: Expose ELF header in compat_start_thread() Like it is done for SET_PERSONALITY with x86, which requires the ELF header to select correct personality parameters, x86 requires the headers on compat_start_thread() to choose starting CS for ELF32 binaries, instead of relying on the going-away TIF_IA32/X32 flags. Add an indirection macro to ELF invocations of START_THREAD, that x86 can reimplement to receive the extra parameter just for ELF files. This requires no changes to other architectures who don't need the header information, they can continue to use the original start_thread for ELF and non-ELF binaries, and it prevents affecting non-ELF code paths for x86. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201004032536.1229030-6-krisman@collabora.com --- fs/binfmt_elf.c | 2 +- fs/compat_binfmt_elf.c | 9 +++++++-- include/linux/elf.h | 5 +++++ 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index b6b3d052ca86..b23f7553fe9b 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1307,7 +1307,7 @@ out_free_interp: #endif finalize_exec(bprm); - start_thread(regs, elf_entry, bprm->p); + START_THREAD(elf_ex, regs, elf_entry, bprm->p); retval = 0; out: return retval; diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index 2d24c765cbd7..12b991368f0a 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -106,8 +106,13 @@ #endif #ifdef compat_start_thread -#undef start_thread -#define start_thread compat_start_thread +#define COMPAT_START_THREAD(ex, regs, new_ip, new_sp) \ + compat_start_thread(regs, new_ip, new_sp) +#endif + +#ifdef COMPAT_START_THREAD +#undef START_THREAD +#define START_THREAD COMPAT_START_THREAD #endif #ifdef compat_arch_setup_additional_pages diff --git a/include/linux/elf.h b/include/linux/elf.h index 5d5b0321da0b..6dbcfe7a3fd7 100644 --- a/include/linux/elf.h +++ b/include/linux/elf.h @@ -22,6 +22,11 @@ SET_PERSONALITY(ex) #endif +#ifndef START_THREAD +#define START_THREAD(elf_ex, regs, elf_entry, start_stack) \ + start_thread(regs, elf_entry, start_stack) +#endif + #define ELF32_GNU_PROPERTY_ALIGN 4 #define ELF64_GNU_PROPERTY_ALIGN 8 From 2424b14605c71a7187c14edd525044eb36bdea47 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:32 -0400 Subject: [PATCH 06/11] x86/elf: Use e_machine to select start_thread for x32 Since TIF_X32 is going away, avoid using it to find the ELF type in compat_start_thread. According to SysV AMD64 ABI Draft, an AMD64 ELF object using ILP32 must have ELFCLASS32 with (E_MACHINE == EM_X86_64), so use that ELF field to differentiate a x32 object from a IA32 object when executing start_thread() in compat mode. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Reviewed-by: Andy Lutomirski Link: https://lore.kernel.org/r/20201004032536.1229030-7-krisman@collabora.com --- arch/x86/include/asm/elf.h | 5 +++-- arch/x86/kernel/process_64.c | 5 ++--- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 9220efc65d78..109697a19eb1 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -186,8 +186,9 @@ static inline void elf_common_init(struct thread_struct *t, #define COMPAT_ELF_PLAT_INIT(regs, load_addr) \ elf_common_init(¤t->thread, regs, __USER_DS) -void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp); -#define compat_start_thread compat_start_thread +void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp, bool x32); +#define COMPAT_START_THREAD(ex, regs, new_ip, new_sp) \ + compat_start_thread(regs, new_ip, new_sp, ex->e_machine == EM_X86_64) void set_personality_ia32(bool); #define COMPAT_SET_PERSONALITY(ex) \ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index df342bedea88..5fb4103101f5 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -511,11 +511,10 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) EXPORT_SYMBOL_GPL(start_thread); #ifdef CONFIG_COMPAT -void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp) +void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp, bool x32) { start_thread_common(regs, new_ip, new_sp, - test_thread_flag(TIF_X32) - ? __USER_CS : __USER32_CS, + x32 ? __USER_CS : __USER32_CS, __USER_DS, __USER_DS); } #endif From 9a29a671902c2be05d636045a4dd365219ca716c Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:33 -0400 Subject: [PATCH 07/11] elf: Expose ELF header on arch_setup_additional_pages() Like it is done for SET_PERSONALITY with ARM, which requires the ELF header to select correct personality parameters, x86 requires the headers when selecting which VDSO to load, instead of relying on the going-away TIF_IA32/X32 flags. Add an indirection macro to arch_setup_additional_pages(), that x86 can reimplement to receive the extra parameter just for ELF files. This requires no changes to other architectures, who can continue to use the original arch_setup_additional_pages for ELF and non-ELF binaries. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201004032536.1229030-8-krisman@collabora.com --- fs/binfmt_elf.c | 2 +- fs/compat_binfmt_elf.c | 11 ++++++++--- include/linux/elf.h | 5 +++++ 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index b23f7553fe9b..aabc11f099cf 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1246,7 +1246,7 @@ out_free_interp: set_binfmt(&elf_format); #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES - retval = arch_setup_additional_pages(bprm, !!interpreter); + retval = ARCH_SETUP_ADDITIONAL_PAGES(bprm, elf_ex, !!interpreter); if (retval < 0) goto out; #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index 12b991368f0a..2c557229696a 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -115,11 +115,16 @@ #define START_THREAD COMPAT_START_THREAD #endif -#ifdef compat_arch_setup_additional_pages +#ifdef compat_arch_setup_additional_pages +#define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \ + compat_arch_setup_additional_pages(bprm, interpreter) +#endif + +#ifdef COMPAT_ARCH_SETUP_ADDITIONAL_PAGES #undef ARCH_HAS_SETUP_ADDITIONAL_PAGES #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1 -#undef arch_setup_additional_pages -#define arch_setup_additional_pages compat_arch_setup_additional_pages +#undef ARCH_SETUP_ADDITIONAL_PAGES +#define ARCH_SETUP_ADDITIONAL_PAGES COMPAT_ARCH_SETUP_ADDITIONAL_PAGES #endif #ifdef compat_elf_read_implies_exec diff --git a/include/linux/elf.h b/include/linux/elf.h index 6dbcfe7a3fd7..c9a46c4e183b 100644 --- a/include/linux/elf.h +++ b/include/linux/elf.h @@ -27,6 +27,11 @@ start_thread(regs, elf_entry, start_stack) #endif +#if defined(ARCH_HAS_SETUP_ADDITIONAL_PAGES) && !defined(ARCH_SETUP_ADDITIONAL_PAGES) +#define ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \ + arch_setup_additional_pages(bprm, interpreter) +#endif + #define ELF32_GNU_PROPERTY_ALIGN 4 #define ELF64_GNU_PROPERTY_ALIGN 8 From 3316ec8ccd34e19690a12e65801d605d25155031 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:34 -0400 Subject: [PATCH 08/11] x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages() Since TIF_X32 is going away, avoid using it to find the ELF type when choosing which additional pages to set up. According to SysV AMD64 ABI Draft, an AMD64 ELF object using ILP32 must have ELFCLASS32 with (E_MACHINE == EM_X86_64), so use that ELF field to differentiate a x32 object from a IA32 object when executing setup_additional_pages() in compat mode. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201004032536.1229030-9-krisman@collabora.com --- arch/x86/entry/vdso/vma.c | 4 ++-- arch/x86/include/asm/elf.h | 6 ++++-- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 9185cb1d13b9..50e5d3a2e70a 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -413,10 +413,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) #ifdef CONFIG_COMPAT int compat_arch_setup_additional_pages(struct linux_binprm *bprm, - int uses_interp) + int uses_interp, bool x32) { #ifdef CONFIG_X86_X32_ABI - if (test_thread_flag(TIF_X32)) { + if (x32) { if (!vdso64_enabled) return 0; return map_vdso_randomized(&vdso_image_x32); diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 109697a19eb1..44a9b9940535 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -383,8 +383,10 @@ struct linux_binprm; extern int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp); extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm, - int uses_interp); -#define compat_arch_setup_additional_pages compat_arch_setup_additional_pages + int uses_interp, bool x32); +#define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \ + compat_arch_setup_additional_pages(bprm, interpreter, \ + (ex->e_machine == EM_X86_64)) /* Do not change the values. See get_align_mask() */ enum align_flags { From ff170cd0595398a7b66cb40f249eb2f10c29b66d Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:35 -0400 Subject: [PATCH 09/11] 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/entry/vsyscall/vsyscall_64.c | 2 +- arch/x86/include/asm/mmu.h | 9 +++++++-- arch/x86/include/asm/mmu_context.h | 2 +- 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 #include #include +#include + +/* 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; From 8d71d2bf6efec3032208958c483a247f529ffb16 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Sat, 3 Oct 2020 23:25:36 -0400 Subject: [PATCH 10/11] x86: Reclaim TIF_IA32 and TIF_X32 Now that these flags are no longer used, reclaim those TIF bits. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201004032536.1229030-11-krisman@collabora.com --- arch/x86/include/asm/thread_info.h | 4 ---- arch/x86/kernel/process_64.c | 6 ------ 2 files changed, 10 deletions(-) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 44733a4bfc42..a12b9644193b 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -91,7 +91,6 @@ struct thread_info { #define TIF_NEED_FPU_LOAD 14 /* load FPU on return to userspace */ #define TIF_NOCPUID 15 /* CPUID is not accessible in userland */ #define TIF_NOTSC 16 /* TSC is not accessible in userland */ -#define TIF_IA32 17 /* IA32 compatibility process */ #define TIF_SLD 18 /* Restore split lock detection on context switch */ #define TIF_MEMDIE 20 /* is terminating due to OOM killer */ #define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */ @@ -101,7 +100,6 @@ struct thread_info { #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */ #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */ #define TIF_ADDR32 29 /* 32-bit address space on 64 bits */ -#define TIF_X32 30 /* 32-bit native x86-64 binary */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) @@ -120,7 +118,6 @@ struct thread_info { #define _TIF_NEED_FPU_LOAD (1 << TIF_NEED_FPU_LOAD) #define _TIF_NOCPUID (1 << TIF_NOCPUID) #define _TIF_NOTSC (1 << TIF_NOTSC) -#define _TIF_IA32 (1 << TIF_IA32) #define _TIF_SLD (1 << TIF_SLD) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) @@ -129,7 +126,6 @@ struct thread_info { #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES) #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) #define _TIF_ADDR32 (1 << TIF_ADDR32) -#define _TIF_X32 (1 << TIF_X32) /* flags to check in __switch_to() */ #define _TIF_WORK_CTXSW_BASE \ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index d6efaf6623c9..ad582f9ac5a6 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -640,9 +640,7 @@ void set_personality_64bit(void) /* inherit personality from parent */ /* Make sure to be in 64bit mode */ - clear_thread_flag(TIF_IA32); clear_thread_flag(TIF_ADDR32); - clear_thread_flag(TIF_X32); /* Pretend that this comes from a 64bit execve */ task_pt_regs(current)->orig_ax = __NR_execve; current_thread_info()->status &= ~TS_COMPAT; @@ -659,8 +657,6 @@ void set_personality_64bit(void) static void __set_personality_x32(void) { #ifdef CONFIG_X86_X32 - clear_thread_flag(TIF_IA32); - set_thread_flag(TIF_X32); if (current->mm) current->mm->context.flags = 0; @@ -681,8 +677,6 @@ static void __set_personality_x32(void) static void __set_personality_ia32(void) { #ifdef CONFIG_IA32_EMULATION - set_thread_flag(TIF_IA32); - clear_thread_flag(TIF_X32); if (current->mm) { /* * uprobes applied to this MM need to know this and From c8d5ed67936fddbe2ae845fc80397718006322d7 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 26 Oct 2020 14:32:29 -0600 Subject: [PATCH 11/11] x86: Wire up TIF_NOTIFY_SIGNAL The generic entry code has support for TIF_NOTIFY_SIGNAL already. Just provide the TIF bit. [ tglx: Adopted to other TIF changes in x86 ] Signed-off-by: Jens Axboe Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201026203230.386348-4-axboe@kernel.dk --- arch/x86/include/asm/thread_info.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index a12b9644193b..06a171037558 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -91,6 +91,7 @@ struct thread_info { #define TIF_NEED_FPU_LOAD 14 /* load FPU on return to userspace */ #define TIF_NOCPUID 15 /* CPUID is not accessible in userland */ #define TIF_NOTSC 16 /* TSC is not accessible in userland */ +#define TIF_NOTIFY_SIGNAL 17 /* signal notifications exist */ #define TIF_SLD 18 /* Restore split lock detection on context switch */ #define TIF_MEMDIE 20 /* is terminating due to OOM killer */ #define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */ @@ -118,6 +119,7 @@ struct thread_info { #define _TIF_NEED_FPU_LOAD (1 << TIF_NEED_FPU_LOAD) #define _TIF_NOCPUID (1 << TIF_NOCPUID) #define _TIF_NOTSC (1 << TIF_NOTSC) +#define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) #define _TIF_SLD (1 << TIF_SLD) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)