diff options
| -rw-r--r-- | arch/um/include/asm/processor-generic.h | 1 | ||||
| -rw-r--r-- | arch/um/include/shared/kern_util.h | 3 | ||||
| -rw-r--r-- | arch/um/include/shared/ptrace_user.h | 41 | ||||
| -rw-r--r-- | arch/um/kernel/process.c | 12 | ||||
| -rw-r--r-- | arch/um/kernel/ptrace.c | 2 | ||||
| -rw-r--r-- | arch/um/kernel/signal.c | 12 | ||||
| -rw-r--r-- | arch/um/os-Linux/skas/process.c | 60 | ||||
| -rw-r--r-- | arch/um/os-Linux/start_up.c | 70 | ||||
| -rw-r--r-- | arch/x86/um/ptrace_32.c | 24 | ||||
| -rw-r--r-- | arch/x86/um/ptrace_64.c | 26 | ||||
| -rw-r--r-- | arch/x86/um/shared/sysdep/ptrace_32.h | 4 | ||||
| -rw-r--r-- | arch/x86/um/shared/sysdep/ptrace_user.h | 12 |
12 files changed, 24 insertions, 243 deletions
diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h index 7414154b8e9a..6c3779541845 100644 --- a/arch/um/include/asm/processor-generic.h +++ b/arch/um/include/asm/processor-generic.h @@ -22,7 +22,6 @@ struct mm_struct; struct thread_struct { struct pt_regs regs; struct pt_regs *segv_regs; - int singlestep_syscall; void *fault_addr; jmp_buf *fault_catcher; struct task_struct *prev_sched; diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h index 444bae755b16..789b83013f35 100644 --- a/arch/um/include/shared/kern_util.h +++ b/arch/um/include/shared/kern_util.h @@ -34,7 +34,6 @@ extern int handle_page_fault(unsigned long address, unsigned long ip, extern unsigned int do_IRQ(int irq, struct uml_pt_regs *regs); extern void initial_thread_cb(void (*proc)(void *), void *arg); -extern int is_syscall(unsigned long addr); extern void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs); @@ -58,7 +57,7 @@ extern char *uml_strdup(const char *string); extern unsigned long to_irq_stack(unsigned long *mask_out); extern unsigned long from_irq_stack(int nested); -extern int singlestepping(void *t); +extern int singlestepping(void); extern void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs); extern void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs); diff --git a/arch/um/include/shared/ptrace_user.h b/arch/um/include/shared/ptrace_user.h index 95455e8996e7..8a705d8f96ce 100644 --- a/arch/um/include/shared/ptrace_user.h +++ b/arch/um/include/shared/ptrace_user.h @@ -12,45 +12,4 @@ extern int ptrace_getregs(long pid, unsigned long *regs_out); extern int ptrace_setregs(long pid, unsigned long *regs_in); -/* syscall emulation path in ptrace */ - -#ifndef PTRACE_SYSEMU -#define PTRACE_SYSEMU 31 -#endif -#ifndef PTRACE_SYSEMU_SINGLESTEP -#define PTRACE_SYSEMU_SINGLESTEP 32 -#endif - -/* On architectures, that started to support PTRACE_O_TRACESYSGOOD - * in linux 2.4, there are two different definitions of - * PTRACE_SETOPTIONS: linux 2.4 uses 21 while linux 2.6 uses 0x4200. - * For binary compatibility, 2.6 also supports the old "21", named - * PTRACE_OLDSETOPTION. On these architectures, UML always must use - * "21", to ensure the kernel runs on 2.4 and 2.6 host without - * recompilation. So, we use PTRACE_OLDSETOPTIONS in UML. - * We also want to be able to build the kernel on 2.4, which doesn't - * have PTRACE_OLDSETOPTIONS. So, if it is missing, we declare - * PTRACE_OLDSETOPTIONS to be the same as PTRACE_SETOPTIONS. - * - * On architectures, that start to support PTRACE_O_TRACESYSGOOD on - * linux 2.6, PTRACE_OLDSETOPTIONS never is defined, and also isn't - * supported by the host kernel. In that case, our trick lets us use - * the new 0x4200 with the name PTRACE_OLDSETOPTIONS. - */ -#ifndef PTRACE_OLDSETOPTIONS -#define PTRACE_OLDSETOPTIONS PTRACE_SETOPTIONS -#endif - -void set_using_sysemu(int value); -int get_using_sysemu(void); -extern int sysemu_supported; - -#define SELECT_PTRACE_OPERATION(sysemu_mode, singlestep_mode) \ - (((int[3][3] ) { \ - { PTRACE_SYSCALL, PTRACE_SYSCALL, PTRACE_SINGLESTEP }, \ - { PTRACE_SYSEMU, PTRACE_SYSEMU, PTRACE_SINGLESTEP }, \ - { PTRACE_SYSEMU, PTRACE_SYSEMU_SINGLESTEP, \ - PTRACE_SYSEMU_SINGLESTEP } }) \ - [sysemu_mode][singlestep_mode]) - #endif diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 6daffb9d8a8d..ab95648e93e1 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -332,17 +332,9 @@ int __init make_proc_sysemu(void) late_initcall(make_proc_sysemu); -int singlestepping(void * t) +int singlestepping(void) { - struct task_struct *task = t ? t : current; - - if (!test_thread_flag(TIF_SINGLESTEP)) - return 0; - - if (task->thread.singlestep_syscall) - return 1; - - return 2; + return test_thread_flag(TIF_SINGLESTEP); } /* diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index 5154b27de580..6600a2782796 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -12,7 +12,6 @@ void user_enable_single_step(struct task_struct *child) { set_tsk_thread_flag(child, TIF_SINGLESTEP); - child->thread.singlestep_syscall = 0; #ifdef SUBARCH_SET_SINGLESTEPPING SUBARCH_SET_SINGLESTEPPING(child, 1); @@ -22,7 +21,6 @@ void user_enable_single_step(struct task_struct *child) void user_disable_single_step(struct task_struct *child) { clear_tsk_thread_flag(child, TIF_SINGLESTEP); - child->thread.singlestep_syscall = 0; #ifdef SUBARCH_SET_SINGLESTEPPING SUBARCH_SET_SINGLESTEPPING(child, 0); diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c index ae4658f576ab..a56b44522766 100644 --- a/arch/um/kernel/signal.c +++ b/arch/um/kernel/signal.c @@ -121,18 +121,6 @@ void do_signal(struct pt_regs *regs) } /* - * This closes a way to execute a system call on the host. If - * you set a breakpoint on a system call instruction and singlestep - * from it, the tracing thread used to PTRACE_SINGLESTEP the process - * rather than PTRACE_SYSCALL it, allowing the system call to execute - * on the host. The tracing thread will check this flag and - * PTRACE_SYSCALL if necessary. - */ - if (test_thread_flag(TIF_SINGLESTEP)) - current->thread.singlestep_syscall = - is_syscall(PT_REGS_IP(¤t->thread.regs)); - - /* * if there's no signal to deliver, we just put the saved sigmask * back */ diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 9464833e741a..43168c51850c 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -177,48 +177,11 @@ static void handle_segv(int pid, struct uml_pt_regs *regs, unsigned long *aux_fp segv(regs->faultinfo, 0, 1, NULL); } -/* - * To use the same value of using_sysemu as the caller, ask it that value - * (in local_using_sysemu - */ -static void handle_trap(int pid, struct uml_pt_regs *regs, - int local_using_sysemu) +static void handle_trap(int pid, struct uml_pt_regs *regs) { - int err, status; - if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END)) fatal_sigsegv(); - if (!local_using_sysemu) - { - err = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET, - __NR_getpid); - if (err < 0) { - printk(UM_KERN_ERR "%s - nullifying syscall failed, errno = %d\n", - __func__, errno); - fatal_sigsegv(); - } - - err = ptrace(PTRACE_SYSCALL, pid, 0, 0); - if (err < 0) { - printk(UM_KERN_ERR "%s - continuing to end of syscall failed, errno = %d\n", - __func__, errno); - fatal_sigsegv(); - } - - CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL)); - if ((err < 0) || !WIFSTOPPED(status) || - (WSTOPSIG(status) != SIGTRAP + 0x80)) { - err = ptrace_dump_regs(pid); - if (err) - printk(UM_KERN_ERR "Failed to get registers from process, errno = %d\n", - -err); - printk(UM_KERN_ERR "%s - failed to wait at end of syscall, errno = %d, status = %d\n", - __func__, errno, status); - fatal_sigsegv(); - } - } - handle_syscall(regs); } @@ -355,10 +318,10 @@ int start_userspace(unsigned long stub_stack) goto out_kill; } - if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, + if (ptrace(PTRACE_SETOPTIONS, pid, NULL, (void *) PTRACE_O_TRACESYSGOOD) < 0) { err = -errno; - printk(UM_KERN_ERR "%s : PTRACE_OLDSETOPTIONS failed, errno = %d\n", + printk(UM_KERN_ERR "%s : PTRACE_SETOPTIONS failed, errno = %d\n", __func__, errno); goto out_kill; } @@ -380,8 +343,6 @@ int start_userspace(unsigned long stub_stack) void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs) { int err, status, op, pid = userspace_pid[0]; - /* To prevent races if using_sysemu changes under us.*/ - int local_using_sysemu; siginfo_t si; /* Handle any immediate reschedules or signals */ @@ -411,11 +372,10 @@ void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs) fatal_sigsegv(); } - /* Now we set local_using_sysemu to be used for one loop */ - local_using_sysemu = get_using_sysemu(); - - op = SELECT_PTRACE_OPERATION(local_using_sysemu, - singlestepping(NULL)); + if (singlestepping()) + op = PTRACE_SYSEMU_SINGLESTEP; + else + op = PTRACE_SYSEMU; if (ptrace(op, pid, 0, 0)) { printk(UM_KERN_ERR "%s - ptrace continue failed, op = %d, errno = %d\n", @@ -474,7 +434,7 @@ void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs) else handle_segv(pid, regs, aux_fp_regs); break; case SIGTRAP + 0x80: - handle_trap(pid, regs, local_using_sysemu); + handle_trap(pid, regs); break; case SIGTRAP: relay_signal(SIGTRAP, (struct siginfo *)&si, regs); @@ -597,10 +557,10 @@ int copy_context_skas0(unsigned long new_stack, int pid) goto out_kill; } - if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, + if (ptrace(PTRACE_SETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0) { err = -errno; - printk(UM_KERN_ERR "%s : PTRACE_OLDSETOPTIONS failed, errno = %d\n", + printk(UM_KERN_ERR "%s : PTRACE_SETOPTIONS failed, errno = %d\n", __func__, errno); goto out_kill; } diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c index e3ee4db58b40..561c08e0cc9c 100644 --- a/arch/um/os-Linux/start_up.c +++ b/arch/um/os-Linux/start_up.c @@ -143,71 +143,16 @@ static int stop_ptraced_child(int pid, int exitcode, int mustexit) return ret; } -/* Changed only during early boot */ -static int force_sysemu_disabled = 0; - -static int __init nosysemu_cmd_param(char *str, int* add) -{ - force_sysemu_disabled = 1; - return 0; -} - -__uml_setup("nosysemu", nosysemu_cmd_param, -"nosysemu\n" -" Turns off syscall emulation patch for ptrace (SYSEMU).\n" -" SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n" -" behaviour of ptrace() and helps reduce host context switch rates.\n" -" To make it work, you need a kernel patch for your host, too.\n" -" See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n" -" information.\n\n"); - static void __init check_sysemu(void) { - unsigned long regs[MAX_REG_NR]; int pid, n, status, count=0; - os_info("Checking syscall emulation patch for ptrace..."); - sysemu_supported = 0; - pid = start_ptraced_child(); - - if (ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) - goto fail; - - CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); - if (n < 0) - fatal_perror("check_sysemu : wait failed"); - if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) - fatal("check_sysemu : expected SIGTRAP, got status = %d\n", - status); - - if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0) - fatal_perror("check_sysemu : PTRACE_GETREGS failed"); - if (PT_SYSCALL_NR(regs) != __NR_getpid) { - non_fatal("check_sysemu got system call number %d, " - "expected %d...", PT_SYSCALL_NR(regs), __NR_getpid); - goto fail; - } - - n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET, os_getpid()); - if (n < 0) { - non_fatal("check_sysemu : failed to modify system call " - "return"); - goto fail; - } - - if (stop_ptraced_child(pid, 0, 0) < 0) - goto fail_stopped; - - sysemu_supported = 1; - os_info("OK\n"); - set_using_sysemu(!force_sysemu_disabled); - - os_info("Checking advanced syscall emulation patch for ptrace..."); + os_info("Checking syscall emulation for ptrace..."); pid = start_ptraced_child(); - if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0, + if ((ptrace(PTRACE_SETOPTIONS, pid, 0, (void *) PTRACE_O_TRACESYSGOOD) < 0)) - fatal_perror("check_sysemu: PTRACE_OLDSETOPTIONS failed"); + fatal_perror("check_sysemu: PTRACE_SETOPTIONS failed"); while (1) { count++; @@ -243,17 +188,14 @@ static void __init check_sysemu(void) if (stop_ptraced_child(pid, 0, 0) < 0) goto fail_stopped; - sysemu_supported = 2; os_info("OK\n"); - if (!force_sysemu_disabled) - set_using_sysemu(sysemu_supported); return; fail: stop_ptraced_child(pid, 1, 0); fail_stopped: - non_fatal("missing\n"); + fatal("missing\n"); } static void __init check_ptrace(void) @@ -263,9 +205,9 @@ static void __init check_ptrace(void) os_info("Checking that ptrace can change system call numbers..."); pid = start_ptraced_child(); - if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0, + if ((ptrace(PTRACE_SETOPTIONS, pid, 0, (void *) PTRACE_O_TRACESYSGOOD) < 0)) - fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed"); + fatal_perror("check_ptrace: PTRACE_SETOPTIONS failed"); while (1) { if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c index 0bc4b73a9cde..7f1abde2c84b 100644 --- a/arch/x86/um/ptrace_32.c +++ b/arch/x86/um/ptrace_32.c @@ -25,30 +25,6 @@ void arch_switch_to(struct task_struct *to) printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n"); } -int is_syscall(unsigned long addr) -{ - unsigned short instr; - int n; - - n = copy_from_user(&instr, (void __user *) addr, sizeof(instr)); - if (n) { - /* access_process_vm() grants access to vsyscall and stub, - * while copy_from_user doesn't. Maybe access_process_vm is - * slow, but that doesn't matter, since it will be called only - * in case of singlestepping, if copy_from_user failed. - */ - n = access_process_vm(current, addr, &instr, sizeof(instr), - FOLL_FORCE); - if (n != sizeof(instr)) { - printk(KERN_ERR "is_syscall : failed to read " - "instruction from 0x%lx\n", addr); - return 1; - } - } - /* int 0x80 or sysenter */ - return (instr == 0x80cd) || (instr == 0x340f); -} - /* determines which flags the user has access to. */ /* 1 = access 0 = no access */ #define FLAG_MASK 0x00044dd5 diff --git a/arch/x86/um/ptrace_64.c b/arch/x86/um/ptrace_64.c index 289d0159b041..aa68d83d3f44 100644 --- a/arch/x86/um/ptrace_64.c +++ b/arch/x86/um/ptrace_64.c @@ -188,32 +188,6 @@ int peek_user(struct task_struct *child, long addr, long data) return put_user(tmp, (unsigned long *) data); } -/* XXX Mostly copied from sys-i386 */ -int is_syscall(unsigned long addr) -{ - unsigned short instr; - int n; - - n = copy_from_user(&instr, (void __user *) addr, sizeof(instr)); - if (n) { - /* - * access_process_vm() grants access to vsyscall and stub, - * while copy_from_user doesn't. Maybe access_process_vm is - * slow, but that doesn't matter, since it will be called only - * in case of singlestepping, if copy_from_user failed. - */ - n = access_process_vm(current, addr, &instr, sizeof(instr), - FOLL_FORCE); - if (n != sizeof(instr)) { - printk("is_syscall : failed to read instruction from " - "0x%lx\n", addr); - return 1; - } - } - /* sysenter */ - return instr == 0x050f; -} - static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child) { int err, n, cpu = ((struct thread_info *) child->stack)->cpu; diff --git a/arch/x86/um/shared/sysdep/ptrace_32.h b/arch/x86/um/shared/sysdep/ptrace_32.h index db8478a83a09..0c4989842fbe 100644 --- a/arch/x86/um/shared/sysdep/ptrace_32.h +++ b/arch/x86/um/shared/sysdep/ptrace_32.h @@ -8,10 +8,6 @@ #define MAX_FP_NR HOST_FPX_SIZE -void set_using_sysemu(int value); -int get_using_sysemu(void); -extern int sysemu_supported; - #define UPT_SYSCALL_ARG1(r) UPT_BX(r) #define UPT_SYSCALL_ARG2(r) UPT_CX(r) #define UPT_SYSCALL_ARG3(r) UPT_DX(r) diff --git a/arch/x86/um/shared/sysdep/ptrace_user.h b/arch/x86/um/shared/sysdep/ptrace_user.h index 44782bbad41e..1d1a824fa652 100644 --- a/arch/x86/um/shared/sysdep/ptrace_user.h +++ b/arch/x86/um/shared/sysdep/ptrace_user.h @@ -15,14 +15,12 @@ #define FP_SIZE ((HOST_FPX_SIZE > HOST_FP_SIZE) ? HOST_FPX_SIZE : HOST_FP_SIZE) #else #define FP_SIZE HOST_FP_SIZE +#endif /* - * x86_64 FC3 doesn't define this in /usr/include/linux/ptrace.h even though - * it's defined in the kernel's include/linux/ptrace.h. Additionally, use the - * 2.4 name and value for 2.4 host compatibility. + * glibc before 2.27 does not include PTRACE_SYSEMU_SINGLESTEP in its enum, + * ensure we have a definition by (re-)defining it here. */ -#ifndef PTRACE_OLDSETOPTIONS -#define PTRACE_OLDSETOPTIONS 21 -#endif - +#ifndef PTRACE_SYSEMU_SINGLESTEP +#define PTRACE_SYSEMU_SINGLESTEP 32 #endif |