Add get_mm and switch_mm support to UML. Index: linux-2.6-skas4/arch/um/include/skas/mm_id.h =================================================================== --- linux-2.6-skas4.orig/arch/um/include/skas/mm_id.h 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/include/skas/mm_id.h 2008-01-09 16:24:45.000000000 -0500 @@ -7,7 +7,7 @@ #define __MM_ID_H struct mm_id { - union { + struct { int mm_fd; int pid; } u; Index: linux-2.6-skas4/arch/um/include/skas/skas.h =================================================================== --- linux-2.6-skas4.orig/arch/um/include/skas/skas.h 2008-01-09 16:22:57.000000000 -0500 +++ linux-2.6-skas4/arch/um/include/skas/skas.h 2008-01-09 16:25:47.000000000 -0500 @@ -6,12 +6,40 @@ #ifndef __SKAS_H #define __SKAS_H +#ifndef __KERNEL__ +#include <unistd.h> +#include <sys/syscall.h> +#endif +#include "uml-config.h" + +#ifdef UML_CONFIG_X86_32 +#define __NR_new_mm 325 +#define __NR_switch_mm 326 +#else +#define __NR_new_mm 286 +#define __NR_switch_mm 287 +#endif + +#define MM_COPY 0 + +#define MM_ALL_REGS 0 +#define MM_SP_IP 1 +#define MM_SAME 2 + +#define PTRACE_SWITCH_MM 33 + +#ifndef __ASSEMBLY__ + #include "sysdep/ptrace.h" extern int userspace_pid[]; extern int proc_mm, ptrace_faultinfo, ptrace_ldt; extern int skas_needs_stub; +extern int have_switch_mm; +extern int self_mm_fd; +extern int have_ptrace_switch_mm; + extern int user_thread(unsigned long stack, int flags); extern void new_thread_handler(void); extern void handle_syscall(struct uml_pt_regs *regs); @@ -20,4 +48,19 @@ extern void get_skas_faultinfo(int pid, extern long execute_syscall_skas(void *r); extern unsigned long current_stub_stack(void); +#ifndef __KERNEL__ +static inline long new_mm(int flags) +{ + return syscall(__NR_new_mm, MM_COPY, 0, 0, 0, 0, 0, 0); +} + +static inline long switch_mm(int mm_fd, unsigned long flags, + unsigned long *new_regs, unsigned long *save_regs) +{ + return syscall(__NR_switch_mm, mm_fd, flags, new_regs, save_regs, 0, 0); +} +#endif + +#endif + #endif Index: linux-2.6-skas4/arch/um/kernel/reboot.c =================================================================== --- linux-2.6-skas4.orig/arch/um/kernel/reboot.c 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/kernel/reboot.c 2008-01-09 16:24:45.000000000 -0500 @@ -11,7 +11,7 @@ void (*pm_power_off)(void); static void kill_off_processes(void) { - if(proc_mm) + if(proc_mm || have_switch_mm) /* * FIXME: need to loop over userspace_pids */ Index: linux-2.6-skas4/arch/um/kernel/skas/mmu.c =================================================================== --- linux-2.6-skas4.orig/arch/um/kernel/skas/mmu.c 2008-01-09 16:24:05.000000000 -0500 +++ linux-2.6-skas4/arch/um/kernel/skas/mmu.c 2008-01-09 16:24:45.000000000 -0500 @@ -65,6 +65,9 @@ static int init_stub_pte(struct mm_struc return -ENOMEM; } +extern int copy_context_skas4(struct mm_id *id); +extern int get_new_mm(void); + int init_new_context(struct task_struct *task, struct mm_struct *mm) { struct mm_context *from_mm = NULL; @@ -109,6 +112,20 @@ int init_new_context(struct task_struct } to_mm->id.u.mm_fd = ret; } + else if (have_switch_mm) { + to_mm->id.u.mm_fd = get_new_mm(); + if(to_mm->id.u.mm_fd < 0) { + ret = to_mm->id.u.mm_fd; + goto out_free; + } + + ret = copy_context_skas4(&to_mm->id); + if (ret < 0) { + os_close_file(to_mm->id.u.mm_fd); + to_mm->id.u.mm_fd = -1; + goto out_free; + } + } else { if (from_mm) to_mm->id.u.pid = copy_context_skas0(stack, @@ -136,11 +153,15 @@ void destroy_context(struct mm_struct *m { struct mm_context *mmu = &mm->context; - if (proc_mm) + if (proc_mm || have_switch_mm) os_close_file(mmu->id.u.mm_fd); - else + else { os_kill_ptraced_process(mmu->id.u.pid, 1); + if (have_switch_mm) + os_close_file(mmu->id.u.mm_fd); + } + if (!proc_mm || !ptrace_faultinfo) { free_page(mmu->id.stack); pte_lock_deinit(virt_to_page(mmu->last_page_table)); Index: linux-2.6-skas4/arch/um/kernel/skas/process.c =================================================================== --- linux-2.6-skas4.orig/arch/um/kernel/skas/process.c 2008-01-09 16:24:05.000000000 -0500 +++ linux-2.6-skas4/arch/um/kernel/skas/process.c 2008-01-09 16:24:45.000000000 -0500 @@ -49,7 +49,7 @@ int __init start_uml(void) { stack_protections((unsigned long) &cpu0_irqstack); set_sigstack(cpu0_irqstack, THREAD_SIZE); - if (proc_mm) + if (proc_mm || have_switch_mm) userspace_pid[0] = start_userspace(0); init_new_thread_signals(); Index: linux-2.6-skas4/arch/um/kernel/um_arch.c =================================================================== --- linux-2.6-skas4.orig/arch/um/kernel/um_arch.c 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/kernel/um_arch.c 2008-01-09 16:24:45.000000000 -0500 @@ -271,7 +271,9 @@ int __init linux_main(int argc, char **a can_do_skas(); - if (proc_mm && ptrace_faultinfo) + if (have_switch_mm) + mode = "SKAS4"; + else if (proc_mm && ptrace_faultinfo) mode = "SKAS3"; else mode = "SKAS0"; Index: linux-2.6-skas4/arch/um/os-Linux/skas/mem.c =================================================================== --- linux-2.6-skas4.orig/arch/um/os-Linux/skas/mem.c 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/os-Linux/skas/mem.c 2008-01-09 16:24:45.000000000 -0500 @@ -6,6 +6,7 @@ #include <stddef.h> #include <unistd.h> #include <errno.h> +#include <signal.h> #include <string.h> #include <sys/mman.h> #include "init.h" @@ -22,7 +23,7 @@ #include "sysdep/stub.h" #include "uml-config.h" -extern unsigned long batch_syscall_stub, __syscall_stub_start; +extern unsigned long batch_syscall_stub, switch_mm_stub, __syscall_stub_start; extern void wait_stub_done(int pid); @@ -43,7 +44,10 @@ static int __init init_syscall_regs(void unsigned long *stub_entry; get_safe_registers(syscall_regs); - stub_entry = &batch_syscall_stub; + if (have_switch_mm) + stub_entry = &switch_mm_stub; + else + stub_entry = &batch_syscall_stub; syscall_regs[REGS_IP_INDEX] = STUB_CODE + ((unsigned long) stub_entry - @@ -126,6 +130,32 @@ static long do_syscall_stub(struct mm_id return ret; } +static long do_syscall_stub_skas4(struct mm_id *mm_idp, void **addr) +{ + long ret; + unsigned long *return_regs; + int err; + sigset_t sigs, old; + + return_regs = (unsigned long *) (mm_idp->stack + UM_KERN_PAGE_SIZE) - + MAX_REG_NR; + *(return_regs - 1) = self_mm_fd; + + return_regs = (unsigned long *) (STUB_DATA + UM_KERN_PAGE_SIZE) - + MAX_REG_NR; + + sigfillset(&sigs); + sigprocmask(SIG_SETMASK, &sigs, &old); + err = switch_mm(mm_idp->u.mm_fd, MM_SP_IP, syscall_regs, return_regs); + sigprocmask(SIG_SETMASK, &old, NULL); + + ret = syscall_stub_done(mm_idp->stack); + + *addr = check_init_stack(mm_idp, NULL); + + return ret; +} + static int flush_syscalls(struct mm_id *mm_idp, void **addr, int extra) { unsigned long *stack = check_init_stack(mm_idp, *addr); @@ -137,7 +167,10 @@ static int flush_syscalls(struct mm_id * if (current + (10 + extra) * sizeof(long) < end) return 0; - return do_syscall_stub(mm_idp, addr); + if (have_switch_mm) + return do_syscall_stub_skas4(mm_idp, addr); + else + return do_syscall_stub(mm_idp, addr); } long run_syscall_stub(struct mm_id *mm_idp, int syscall, @@ -166,8 +199,12 @@ long run_syscall_stub(struct mm_id *mm_i *stack++ = expected; *stack = 0; - if (done) - return do_syscall_stub(mm_idp, addr); + if (done) { + if (have_switch_mm) + return do_syscall_stub_skas4(mm_idp, addr); + else + return do_syscall_stub(mm_idp, addr); + } *addr = stack; Index: linux-2.6-skas4/arch/um/os-Linux/skas/process.c =================================================================== --- linux-2.6-skas4.orig/arch/um/os-Linux/skas/process.c 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/os-Linux/skas/process.c 2008-01-09 16:24:45.000000000 -0500 @@ -331,7 +331,7 @@ static int userspace_tramp(void *stack) } } } - if (!ptrace_faultinfo && (stack != NULL)) { + if (!ptrace_faultinfo) { struct sigaction sa; unsigned long v = STUB_CODE + @@ -375,7 +375,7 @@ int start_userspace(unsigned long stub_s sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *); flags = CLONE_FILES; - if (proc_mm) + if (proc_mm || have_switch_mm) flags |= CLONE_VM; else flags |= SIGCHLD; @@ -488,8 +488,14 @@ void userspace(struct uml_pt_regs *regs) printk(UM_KERN_ERR "userspace - child stopped " "with signal %d\n", sig); } - pid = userspace_pid[0]; + + /* + * userspace_pid can change in in_interrupt since + * PTRACE_SWITCH_MM can cause a process to change + * address spaces + */ interrupt_end(); + pid = userspace_pid[0]; /* Avoid -ERESTARTSYS handling in host */ if (PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET) @@ -577,6 +583,69 @@ int copy_context_skas0(unsigned long new return pid; } +extern unsigned long switch_mm_stub; +extern long task_size; + +static void unmap_new_as(void) +{ + void (*p)(void); + void *addr; + unsigned long stack = (unsigned long) &stack & ~(UM_KERN_PAGE_SIZE - 1); + unsigned long long data_offset, code_offset; + int fd = phys_mapping(to_phys((void *) stack), &data_offset); + + addr = mmap((void *) STUB_DATA, UM_KERN_PAGE_SIZE, + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, + data_offset); + if (addr == MAP_FAILED) + panic("Failed to remap stack"); + + fd = phys_mapping(to_phys(&__syscall_stub_start), &code_offset); + addr = mmap((void *) STUB_CODE, UM_KERN_PAGE_SIZE, + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, + code_offset); + if (addr == MAP_FAILED) + panic("Failed to remap code"); + + p = (void (*)(void)) (STUB_CODE + + ((unsigned long) &switch_mm_stub - + (unsigned long) &__syscall_stub_start)); + (*p)(); +} + +int copy_context_skas4(struct mm_id *id) +{ + void *data = NULL; + unsigned long *return_regs, *fd_ptr, regs[MAX_REG_NR]; + sigset_t sigs, old; + int err; + + err = unmap(id, 0, STUB_START, 0, &data); + if (err) + return err; + + err = unmap(id, STUB_END, task_size - STUB_END, 0, &data); + if (err) + return err; + + return_regs = (unsigned long *) (id->stack + UM_KERN_PAGE_SIZE - + MAX_REG_NR * sizeof(long)); + fd_ptr = return_regs - 1; + *fd_ptr = self_mm_fd; + + regs[REGS_IP_INDEX] = (unsigned long) unmap_new_as; + regs[REGS_SP_INDEX] = id->stack + UM_KERN_PAGE_SIZE / 2; + + sigfillset(&sigs); + sigprocmask(SIG_SETMASK, &sigs, &old); + + err = switch_mm(id->u.mm_fd, MM_SP_IP, regs, return_regs); + + sigprocmask(SIG_SETMASK, &old, NULL); + + return err; +} + /* * This is used only, if stub pages are needed, while proc_mm is * available. Opening /proc/mm creates a new mm_context, which lacks @@ -737,5 +806,12 @@ void __switch_mm(struct mm_id *mm_idp) panic("__switch_mm - PTRACE_SWITCH_MM failed, " "errno = %d\n", errno); } + else if (have_ptrace_switch_mm) { + err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0, + mm_idp->u.mm_fd); + if (err) + panic("__switch_mm - PTRACE_SWITCH_MM " + "failed, errno = %d\n", errno); + } else userspace_pid[0] = mm_idp->u.pid; } Index: linux-2.6-skas4/arch/um/os-Linux/start_up.c =================================================================== --- linux-2.6-skas4.orig/arch/um/os-Linux/start_up.c 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/os-Linux/start_up.c 2008-01-09 16:24:45.000000000 -0500 @@ -475,13 +475,208 @@ static inline void check_skas3_proc_mm(v } } -void can_do_skas(void) +static void can_do_skas3(void) { non_fatal("Checking for the skas3 patch in the host:\n"); check_skas3_proc_mm(); check_skas3_ptrace_faultinfo(); check_skas3_ptrace_ldt(); +} + +int get_new_mm(void) +{ + int err; + + err = new_mm(MM_COPY); + if (err < 0) + err = -errno; + + return err; +} + +static char *mm_stack; +static unsigned long return_regs[MAX_REG_NR]; +int self_mm_fd; + +static int switch_mm_works; + +static void after_switch(void) +{ + switch_mm_works = 0; + + switch_mm(self_mm_fd, MM_ALL_REGS, return_regs, NULL); +} + +static int check_switch_mm(void) +{ + unsigned long regs[MAX_REG_NR]; + int err, there = -1; + + non_fatal("\t/proc/self/mm ... "); + self_mm_fd = open("/proc/self/mm", O_RDONLY); + if (self_mm_fd < 0) + goto bad; + non_fatal("OK\n"); + + mm_stack = mmap(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if(mm_stack == MAP_FAILED) + goto bad; + + non_fatal("\tnew_mm ... "); + there = new_mm(MM_COPY); + if(there < 0) + goto bad; + non_fatal("OK\n"); + + regs[REGS_IP_INDEX] = (unsigned long) after_switch; + regs[REGS_SP_INDEX] = ((unsigned long) &mm_stack[UM_KERN_PAGE_SIZE]) - + sizeof(void *); + + non_fatal("\tswitching over ... "); + err = switch_mm(there, MM_SP_IP, regs, return_regs); + if (err < 0) + goto bad; + non_fatal("switched back ... "); + switch_mm_works = 1; + if(!switch_mm_works) + goto bad; + else + non_fatal("OK\n"); + + munmap(mm_stack, UM_KERN_PAGE_SIZE); + close(there); + + if (disable_switch_mm) + non_fatal("SKAS4 support disabled on command line\n"); + else + have_switch_mm = 1; + + return 1; + bad: + if (there > 0) + close(there); + munmap(mm_stack, UM_KERN_PAGE_SIZE); + non_fatal("Failed - \n"); + perror(""); + return 0; +} + +int have_ptrace_switch_mm; +static int disable_ptrace_switch_mm; + +static int ptrace_switch_mm_works; + +static int after_ptrace_switch(void) +{ + ptrace_switch_mm_works = 1; + exit(0); +} + +static int check_ptrace_switch_mm(void) +{ + void *stack; + unsigned long regs[MAX_REG_NR]; + int pid, here, err, status; + + non_fatal("\tPTRACE_SWITCH_MM ... "); + pid = fork(); + if(pid == 0){ + ptrace(PTRACE_TRACEME, 0, 0, 0); + kill(getpid(), SIGSTOP); + + exit(0); + } + else if(pid < 0) + goto bad; + + stack = mmap(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); + if(stack == MAP_FAILED) + goto bad; + + here = open("/proc/self/mm", O_RDONLY); + if(here < 0) + goto bad_unmap; + + err = waitpid(pid, &status, WUNTRACED); + if (err < 0) + goto bad_close; + else if (err != pid) { + non_fatal("waitpid returned %d, expected %d\n", err, pid); + goto bad_close; + } + else if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) { + non_fatal("waitpid returned status 0x%d\n", status); + goto bad_close; + } + + err = ptrace(PTRACE_GETREGS, pid, 0, regs); + if (err < 0) + goto bad_close; + + regs[REGS_IP_INDEX] = (unsigned long) after_ptrace_switch; + regs[REGS_SP_INDEX] = (unsigned long) stack + UM_KERN_PAGE_SIZE - + sizeof(void *); + + if (ptrace(PTRACE_SETREGS, pid, 0, regs) < 0) + goto bad_close; + + if (ptrace(PTRACE_SWITCH_MM, pid, NULL, here) < 0) + goto bad_close; + + if (ptrace(PTRACE_CONT, pid, NULL, 0) < 0) + goto bad_close; + + err = waitpid(pid, &status, WUNTRACED); + if (err < 0) + goto bad_close; + else if(err != pid) { + non_fatal("waitpid returned %d, expected %d\n", err, pid); + goto bad_close; + } + else if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) { + non_fatal("waitpid returned status 0x%d\n", status); + goto bad_close; + } + + if (!ptrace_switch_mm_works) + goto bad_close; + else non_fatal("OK\n"); + + if (disable_ptrace_switch_mm) + non_fatal("PTRACE_SWITCH_MM support disabled on command " + "line\n"); + else + have_ptrace_switch_mm = 1; + + close(here); + munmap(stack, UM_KERN_PAGE_SIZE); + + return 1; + + bad_close: + close(here); + bad_unmap: + munmap(stack, UM_KERN_PAGE_SIZE); + bad: + non_fatal("Failed - \n"); + perror(""); + return 0; +} + +static int can_do_skas4(void) +{ + non_fatal("Checking for new_mm and switch_mm support in the host:\n"); + + return check_switch_mm() && check_ptrace_switch_mm(); +} + +void can_do_skas(void) +{ + if(!can_do_skas4()) + can_do_skas3(); if (!proc_mm || !ptrace_faultinfo || !ptrace_ldt) skas_needs_stub = 1; Index: linux-2.6-skas4/arch/um/sys-i386/stub.S =================================================================== --- linux-2.6-skas4.orig/arch/um/sys-i386/stub.S 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/sys-i386/stub.S 2008-01-09 16:24:45.000000000 -0500 @@ -1,5 +1,8 @@ #include "uml-config.h" #include "as-layout.h" +#include "skas/skas.h" + +#define MAX_REG_NR 17 #define PROCESS_LIST \ /* load pointer to first operation */ \ @@ -43,3 +46,16 @@ batch_syscall_stub: PROCESS_LIST /* stop */ int3 + + .globl switch_mm_stub +switch_mm_stub: + PROCESS_LIST + + mov $__NR_switch_mm, %eax + mov ASM_STUB_DATA + UM_KERN_PAGE_SIZE - MAX_REG_NR * 4 - 4, %ebx + mov $MM_ALL_REGS, %ecx + mov $(ASM_STUB_DATA + UM_KERN_PAGE_SIZE - MAX_REG_NR * 4), %edx + xor %esi, %esi + int $0x80 + + int3 Index: linux-2.6-skas4/arch/um/sys-x86_64/stub.S =================================================================== --- linux-2.6-skas4.orig/arch/um/sys-x86_64/stub.S 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/sys-x86_64/stub.S 2008-01-09 16:24:45.000000000 -0500 @@ -1,5 +1,8 @@ #include "uml-config.h" #include "as-layout.h" +#include "skas/skas.h" + +#define MAX_REG_NR 27 #define PROCESS_LIST \ mov $(ASM_STUB_DATA >> 32), %rbx; \ @@ -46,3 +49,21 @@ batch_syscall_stub: PROCESS_LIST /* stop */ int3 + + .globl switch_mm_stub +switch_mm_stub: + PROCESS_LIST + + mov $__NR_switch_mm, %rax + mov $(ASM_STUB_DATA >> 32), %rdi + sal $32, %rdi + mov $(ASM_STUB_DATA & 0xffffffff), %rsi + add %rsi, %rdi + add $(UM_KERN_PAGE_SIZE - MAX_REG_NR * 8 - 8), %rdi + mov (%rdi), %rdi + mov $MM_ALL_REGS, %rsi + mov $(ASM_STUB_DATA + UM_KERN_PAGE_SIZE - MAX_REG_NR * 8), %rdx + xor %r10, %r10 + syscall + + int3 Index: linux-2.6-skas4/arch/um/sys-x86_64/syscalls.c =================================================================== --- linux-2.6-skas4.orig/arch/um/sys-x86_64/syscalls.c 2008-01-09 16:22:13.000000000 -0500 +++ linux-2.6-skas4/arch/um/sys-x86_64/syscalls.c 2008-01-09 16:24:45.000000000 -0500 @@ -30,7 +30,7 @@ long arch_prctl(struct task_struct *task { unsigned long *ptr = addr, tmp; long ret; - int pid = task->mm->context.id.u.pid; + int pid = userspace_pid[0]; /* * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
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