Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753302Ab2BTAVS (ORCPT ); Sun, 19 Feb 2012 19:21:18 -0500 Received: from terminus.zytor.com ([198.137.202.10]:57398 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752410Ab2BTAVP (ORCPT ); Sun, 19 Feb 2012 19:21:15 -0500 From: "H. Peter Anvin" To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Cc: mingo@kernel.org, tglx@linutronix.de, hpa@zytor.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, hjl.tools@gmail.com, Peter Zijlstra Subject: [PATCH 27/30] x32: Handle process creation Date: Sun, 19 Feb 2012 16:08:05 -0800 Message-Id: <1329696488-16970-28-git-send-email-hpa@zytor.com> X-Mailer: git-send-email 1.7.6.5 In-Reply-To: <1329696488-16970-1-git-send-email-hpa@zytor.com> References: <1329696488-16970-1-git-send-email-hpa@zytor.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Sun, 19 Feb 2012 16:21:05 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7008 Lines: 233 From: "H. Peter Anvin" Allow an x32 process to be started. Originally-by: H. J. Lu Signed-off-by: H. Peter Anvin Cc: Peter Zijlstra --- arch/x86/include/asm/compat.h | 26 ++++++++++++++++++++++++-- arch/x86/include/asm/elf.h | 25 +++++++++++++++++++++---- arch/x86/kernel/cpu/perf_event.c | 4 +++- arch/x86/kernel/entry_64.S | 15 +++++++++++++++ arch/x86/kernel/process_64.c | 23 ++++++++++++++++------- 5 files changed, 79 insertions(+), 14 deletions(-) diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index 7938b84..e7f68b4 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -6,6 +6,7 @@ */ #include #include +#include #include #include @@ -187,7 +188,20 @@ struct compat_shmid64_ds { /* * The type of struct elf_prstatus.pr_reg in compatible core dumps. */ +#ifdef CONFIG_X86_X32_ABI +typedef struct user_regs_struct compat_elf_gregset_t; + +#define PR_REG_SIZE(S) (test_thread_flag(TIF_IA32) ? 68 : 216) +#define PRSTATUS_SIZE(S) (test_thread_flag(TIF_IA32) ? 144 : 296) +#define SET_PR_FPVALID(S,V) \ + do { *(int *) (((void *) &((S)->pr_reg)) + PR_REG_SIZE(0)) = (V); } \ + while (0) + +#define COMPAT_USE_64BIT_TIME \ + (!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT)) +#else typedef struct user_regs_struct32 compat_elf_gregset_t; +#endif /* * A pointer passed in from user mode. This should not @@ -209,8 +223,16 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr) static inline void __user *arch_compat_alloc_user_space(long len) { - struct pt_regs *regs = task_pt_regs(current); - return (void __user *)regs->sp - len; + compat_uptr_t sp; + + if (test_thread_flag(TIF_IA32)) { + sp = task_pt_regs(current)->sp; + } else { + /* -128 for the x32 ABI redzone */ + sp = percpu_read(old_rsp) - 128; + } + + return (void __user *)round_down(sp - len, 16); } static inline bool is_compat_task(void) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 410fa6a..83aabea 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -156,7 +156,12 @@ do { \ #define elf_check_arch(x) \ ((x)->e_machine == EM_X86_64) -#define compat_elf_check_arch(x) elf_check_arch_ia32(x) +#define compat_elf_check_arch(x) \ + (elf_check_arch_ia32(x) || (x)->e_machine == EM_X86_64) + +#if __USER32_DS != __USER_DS +# error "The following code assumes __USER32_DS == __USER_DS" +#endif static inline void elf_common_init(struct thread_struct *t, struct pt_regs *regs, const u16 ds) @@ -179,8 +184,9 @@ static inline void elf_common_init(struct thread_struct *t, void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp); #define compat_start_thread start_thread_ia32 -void set_personality_ia32(void); -#define COMPAT_SET_PERSONALITY(ex) set_personality_ia32() +void set_personality_ia32(bool); +#define COMPAT_SET_PERSONALITY(ex) \ + set_personality_ia32((ex).e_machine == EM_X86_64) #define COMPAT_ELF_PLATFORM ("i686") @@ -296,9 +302,20 @@ do { \ (unsigned long)current->mm->context.vdso); \ } while (0) +#define ARCH_DLINFO_X32 \ +do { \ + if (vdso_enabled) \ + NEW_AUX_ENT(AT_SYSINFO_EHDR, \ + (unsigned long)current->mm->context.vdso); \ +} while (0) + #define AT_SYSINFO 32 -#define COMPAT_ARCH_DLINFO ARCH_DLINFO_IA32(sysctl_vsyscall32) +#define COMPAT_ARCH_DLINFO \ +if (test_thread_flag(TIF_X32)) \ + ARCH_DLINFO_X32; \ +else \ + ARCH_DLINFO_IA32(sysctl_vsyscall32) #define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 5adce10..63c0e05 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -28,7 +28,6 @@ #include #include #include -#include #include #include @@ -1595,6 +1594,9 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) } #ifdef CONFIG_COMPAT + +#include + static inline int perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) { diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 53dc821..9e036f0 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -763,6 +763,21 @@ ENTRY(stub_x32_rt_sigreturn) CFI_ENDPROC END(stub_x32_rt_sigreturn) +ENTRY(stub_x32_execve) + CFI_STARTPROC + addq $8, %rsp + PARTIAL_FRAME 0 + SAVE_REST + FIXUP_TOP_OF_STACK %r11 + movq %rsp, %rcx + call sys32_execve + RESTORE_TOP_OF_STACK %r11 + movq %rax,RAX(%rsp) + RESTORE_REST + jmp int_ret_from_sys_call + CFI_ENDPROC +END(stub_x32_execve) + #endif /* diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 5fe2fba..a0701da 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -364,7 +364,9 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp) { start_thread_common(regs, new_ip, new_sp, - __USER32_CS, __USER32_DS, __USER32_DS); + test_thread_flag(TIF_X32) + ? __USER_CS : __USER32_CS, + __USER_DS, __USER_DS); } #endif @@ -508,6 +510,7 @@ void set_personality_64bit(void) /* Make sure to be in 64bit mode */ clear_thread_flag(TIF_IA32); + clear_thread_flag(TIF_X32); clear_thread_flag(TIF_ADDR32); clear_thread_flag(TIF_X32); @@ -522,22 +525,28 @@ void set_personality_64bit(void) current->personality &= ~READ_IMPLIES_EXEC; } -void set_personality_ia32(void) +void set_personality_ia32(bool x32) { /* inherit personality from parent */ /* Make sure to be in 32bit mode */ - set_thread_flag(TIF_IA32); set_thread_flag(TIF_ADDR32); - clear_thread_flag(TIF_X32); - current->personality |= force_personality32; /* Mark the associated mm as containing 32-bit tasks. */ if (current->mm) current->mm->context.ia32_compat = 1; - /* Prepare the first "return" to user space */ - current_thread_info()->status |= TS_COMPAT; + if (x32) { + clear_thread_flag(TIF_IA32); + set_thread_flag(TIF_X32); + current->personality &= ~READ_IMPLIES_EXEC; + } else { + set_thread_flag(TIF_IA32); + clear_thread_flag(TIF_X32); + current->personality |= force_personality32; + /* Prepare the first "return" to user space */ + current_thread_info()->status |= TS_COMPAT; + } } unsigned long get_wchan(struct task_struct *p) -- 1.7.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/