From d0b5e15f0c0fdd759dd3dd48dc2dc2e7199e0da0 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Wed, 18 Mar 2015 21:31:27 +0100 Subject: um: Remove SKAS3/4 support Before we had SKAS0 UML had two modes of operation TT (tracing thread) and SKAS3/4 (separated kernel address space). TT was known to be insecure and got removed a long time ago. SKAS3/4 required a few (3 or 4) patches on the host side which never went mainline. The last host patch is 10 years old. With SKAS0 mode (separated kernel address space using 0 host patches), default since 2005, SKAS3/4 is obsolete and can be removed. Signed-off-by: Richard Weinberger --- arch/um/os-Linux/skas/mem.c | 100 +++----------------- arch/um/os-Linux/skas/process.c | 200 ++++++++++------------------------------ 2 files changed, 62 insertions(+), 238 deletions(-) (limited to 'arch/um/os-Linux/skas') diff --git a/arch/um/os-Linux/skas/mem.c b/arch/um/os-Linux/skas/mem.c index 689b18db798f..e7f8c945a573 100644 --- a/arch/um/os-Linux/skas/mem.c +++ b/arch/um/os-Linux/skas/mem.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -46,8 +45,6 @@ static int __init init_syscall_regs(void) __initcall(init_syscall_regs); -extern int proc_mm; - static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr) { int n, i; @@ -56,10 +53,6 @@ static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr) unsigned long * syscall; int err, pid = mm_idp->u.pid; - if (proc_mm) - /* FIXME: Need to look up userspace_pid by cpu */ - pid = userspace_pid[0]; - n = ptrace_setregs(pid, syscall_regs); if (n < 0) { printk(UM_KERN_ERR "Registers - \n"); @@ -178,38 +171,12 @@ int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot, int phys_fd, unsigned long long offset, int done, void **data) { int ret; + unsigned long args[] = { virt, len, prot, + MAP_SHARED | MAP_FIXED, phys_fd, + MMAP_OFFSET(offset) }; - if (proc_mm) { - struct proc_mm_op map; - int fd = mm_idp->u.mm_fd; - - map = ((struct proc_mm_op) { .op = MM_MMAP, - .u = - { .mmap = - { .addr = virt, - .len = len, - .prot = prot, - .flags = MAP_SHARED | - MAP_FIXED, - .fd = phys_fd, - .offset= offset - } } } ); - CATCH_EINTR(ret = write(fd, &map, sizeof(map))); - if (ret != sizeof(map)) { - ret = -errno; - printk(UM_KERN_ERR "map : /proc/mm map failed, " - "err = %d\n", -ret); - } - else ret = 0; - } - else { - unsigned long args[] = { virt, len, prot, - MAP_SHARED | MAP_FIXED, phys_fd, - MMAP_OFFSET(offset) }; - - ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt, - data, done); - } + ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt, + data, done); return ret; } @@ -218,32 +185,11 @@ int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len, int done, void **data) { int ret; + unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0, + 0 }; - if (proc_mm) { - struct proc_mm_op unmap; - int fd = mm_idp->u.mm_fd; - - unmap = ((struct proc_mm_op) { .op = MM_MUNMAP, - .u = - { .munmap = - { .addr = - (unsigned long) addr, - .len = len } } } ); - CATCH_EINTR(ret = write(fd, &unmap, sizeof(unmap))); - if (ret != sizeof(unmap)) { - ret = -errno; - printk(UM_KERN_ERR "unmap - proc_mm write returned " - "%d\n", ret); - } - else ret = 0; - } - else { - unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0, - 0 }; - - ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0, - data, done); - } + ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0, + data, done); return ret; } @@ -251,33 +197,11 @@ int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len, int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len, unsigned int prot, int done, void **data) { - struct proc_mm_op protect; int ret; + unsigned long args[] = { addr, len, prot, 0, 0, 0 }; - if (proc_mm) { - int fd = mm_idp->u.mm_fd; - - protect = ((struct proc_mm_op) { .op = MM_MPROTECT, - .u = - { .mprotect = - { .addr = - (unsigned long) addr, - .len = len, - .prot = prot } } } ); - - CATCH_EINTR(ret = write(fd, &protect, sizeof(protect))); - if (ret != sizeof(protect)) { - ret = -errno; - printk(UM_KERN_ERR "protect failed, err = %d", -ret); - } - else ret = 0; - } - else { - unsigned long args[] = { addr, len, prot, 0, 0, 0 }; - - ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0, - data, done); - } + ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0, + data, done); return ret; } diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 908579f2b0ab..50ebeae5cbb3 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -16,11 +16,9 @@ #include #include #include -#include #include #include #include -#include #include int is_skas_winch(int pid, int fd, void *data) @@ -91,50 +89,33 @@ extern unsigned long current_stub_stack(void); static void get_skas_faultinfo(int pid, struct faultinfo *fi) { int err; + unsigned long fpregs[FP_SIZE]; - if (ptrace_faultinfo) { - err = ptrace(PTRACE_FAULTINFO, pid, 0, fi); - if (err) { - printk(UM_KERN_ERR "get_skas_faultinfo - " - "PTRACE_FAULTINFO failed, errno = %d\n", errno); - fatal_sigsegv(); - } - - /* Special handling for i386, which has different structs */ - if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo)) - memset((char *)fi + sizeof(struct ptrace_faultinfo), 0, - sizeof(struct faultinfo) - - sizeof(struct ptrace_faultinfo)); + err = get_fp_registers(pid, fpregs); + if (err < 0) { + printk(UM_KERN_ERR "save_fp_registers returned %d\n", + err); + fatal_sigsegv(); } - else { - unsigned long fpregs[FP_SIZE]; - - err = get_fp_registers(pid, fpregs); - if (err < 0) { - printk(UM_KERN_ERR "save_fp_registers returned %d\n", - err); - fatal_sigsegv(); - } - err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV); - if (err) { - printk(UM_KERN_ERR "Failed to continue stub, pid = %d, " - "errno = %d\n", pid, errno); - fatal_sigsegv(); - } - wait_stub_done(pid); + err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV); + if (err) { + printk(UM_KERN_ERR "Failed to continue stub, pid = %d, " + "errno = %d\n", pid, errno); + fatal_sigsegv(); + } + wait_stub_done(pid); - /* - * faultinfo is prepared by the stub-segv-handler at start of - * the stub stack page. We just have to copy it. - */ - memcpy(fi, (void *)current_stub_stack(), sizeof(*fi)); + /* + * faultinfo is prepared by the stub-segv-handler at start of + * the stub stack page. We just have to copy it. + */ + memcpy(fi, (void *)current_stub_stack(), sizeof(*fi)); - err = put_fp_registers(pid, fpregs); - if (err < 0) { - printk(UM_KERN_ERR "put_fp_registers returned %d\n", - err); - fatal_sigsegv(); - } + err = put_fp_registers(pid, fpregs); + if (err < 0) { + printk(UM_KERN_ERR "put_fp_registers returned %d\n", + err); + fatal_sigsegv(); } } @@ -198,7 +179,8 @@ extern int __syscall_stub_start; static int userspace_tramp(void *stack) { void *addr; - int err; + int err, fd; + unsigned long long offset; ptrace(PTRACE_TRACEME, 0, 0, 0); @@ -211,36 +193,32 @@ static int userspace_tramp(void *stack) exit(1); } - if (!proc_mm) { - /* - * This has a pte, but it can't be mapped in with the usual - * tlb_flush mechanism because this is part of that mechanism - */ - int fd; - unsigned long long offset; - fd = phys_mapping(to_phys(&__syscall_stub_start), &offset); - addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE, - PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset); + /* + * This has a pte, but it can't be mapped in with the usual + * tlb_flush mechanism because this is part of that mechanism + */ + fd = phys_mapping(to_phys(&__syscall_stub_start), &offset); + addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE, + PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset); + if (addr == MAP_FAILED) { + printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, " + "errno = %d\n", STUB_CODE, errno); + exit(1); + } + + if (stack != NULL) { + fd = phys_mapping(to_phys(stack), &offset); + addr = mmap((void *) STUB_DATA, + UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_FIXED | MAP_SHARED, fd, offset); if (addr == MAP_FAILED) { - printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, " - "errno = %d\n", STUB_CODE, errno); + printk(UM_KERN_ERR "mapping segfault stack " + "at 0x%lx failed, errno = %d\n", + STUB_DATA, errno); exit(1); } - - if (stack != NULL) { - fd = phys_mapping(to_phys(stack), &offset); - addr = mmap((void *) STUB_DATA, - UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, - MAP_FIXED | MAP_SHARED, fd, offset); - if (addr == MAP_FAILED) { - printk(UM_KERN_ERR "mapping segfault stack " - "at 0x%lx failed, errno = %d\n", - STUB_DATA, errno); - exit(1); - } - } } - if (!ptrace_faultinfo && (stack != NULL)) { + if (stack != NULL) { struct sigaction sa; unsigned long v = STUB_CODE + @@ -286,11 +264,7 @@ int start_userspace(unsigned long stub_stack) sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *); - flags = CLONE_FILES; - if (proc_mm) - flags |= CLONE_VM; - else - flags |= SIGCHLD; + flags = CLONE_FILES | SIGCHLD; pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack); if (pid < 0) { @@ -413,8 +387,7 @@ void userspace(struct uml_pt_regs *regs) switch (sig) { case SIGSEGV: - if (PTRACE_FULL_FAULTINFO || - !ptrace_faultinfo) { + if (PTRACE_FULL_FAULTINFO) { get_skas_faultinfo(pid, ®s->faultinfo); (*sig_info[SIGSEGV])(SIGSEGV, (struct siginfo *)&si, @@ -571,67 +544,6 @@ int copy_context_skas0(unsigned long new_stack, int pid) 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 - * the stub-pages. Thus, we map them using /proc/mm-fd - */ -int map_stub_pages(int fd, unsigned long code, unsigned long data, - unsigned long stack) -{ - struct proc_mm_op mmop; - int n; - unsigned long long code_offset; - int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start), - &code_offset); - - mmop = ((struct proc_mm_op) { .op = MM_MMAP, - .u = - { .mmap = - { .addr = code, - .len = UM_KERN_PAGE_SIZE, - .prot = PROT_EXEC, - .flags = MAP_FIXED | MAP_PRIVATE, - .fd = code_fd, - .offset = code_offset - } } }); - CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop))); - if (n != sizeof(mmop)) { - n = errno; - printk(UM_KERN_ERR "mmap args - addr = 0x%lx, fd = %d, " - "offset = %llx\n", code, code_fd, - (unsigned long long) code_offset); - printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for code " - "failed, err = %d\n", n); - return -n; - } - - if (stack) { - unsigned long long map_offset; - int map_fd = phys_mapping(to_phys((void *)stack), &map_offset); - mmop = ((struct proc_mm_op) - { .op = MM_MMAP, - .u = - { .mmap = - { .addr = data, - .len = UM_KERN_PAGE_SIZE, - .prot = PROT_READ | PROT_WRITE, - .flags = MAP_FIXED | MAP_SHARED, - .fd = map_fd, - .offset = map_offset - } } }); - CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop))); - if (n != sizeof(mmop)) { - n = errno; - printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for " - "data failed, err = %d\n", n); - return -n; - } - } - - return 0; -} - void new_thread(void *stack, jmp_buf *buf, void (*handler)(void)) { (*buf)[0].JB_IP = (unsigned long) handler; @@ -728,17 +640,5 @@ void reboot_skas(void) void __switch_mm(struct mm_id *mm_idp) { - int err; - - /* FIXME: need cpu pid in __switch_mm */ - if (proc_mm) { - err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0, - mm_idp->u.mm_fd); - if (err) { - printk(UM_KERN_ERR "__switch_mm - PTRACE_SWITCH_MM " - "failed, errno = %d\n", errno); - fatal_sigsegv(); - } - } - else userspace_pid[0] = mm_idp->u.pid; + userspace_pid[0] = mm_idp->u.pid; } -- cgit v1.2.3