diff options
Diffstat (limited to 'security/sandbox/chromium/sandbox/linux/services/syscall_wrappers.cc')
| -rw-r--r-- | security/sandbox/chromium/sandbox/linux/services/syscall_wrappers.cc | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/security/sandbox/chromium/sandbox/linux/services/syscall_wrappers.cc b/security/sandbox/chromium/sandbox/linux/services/syscall_wrappers.cc new file mode 100644 index 0000000000..fcfd2aa129 --- /dev/null +++ b/security/sandbox/chromium/sandbox/linux/services/syscall_wrappers.cc @@ -0,0 +1,264 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "sandbox/linux/services/syscall_wrappers.h" + +#include <pthread.h> +#include <sched.h> +#include <setjmp.h> +#include <sys/resource.h> +#include <sys/syscall.h> +#include <sys/time.h> +#include <sys/types.h> +#include <unistd.h> +#include <cstring> + +#include "base/compiler_specific.h" +#include "base/logging.h" +#include "build/build_config.h" +#include "sandbox/linux/system_headers/capability.h" +#include "sandbox/linux/system_headers/linux_signal.h" +#include "sandbox/linux/system_headers/linux_syscalls.h" + +namespace sandbox { + +pid_t sys_getpid(void) { + return syscall(__NR_getpid); +} + +pid_t sys_gettid(void) { + return syscall(__NR_gettid); +} + +ssize_t sys_write(int fd, const char* buffer, size_t buffer_size) { + return syscall(__NR_write, fd, buffer, buffer_size); +} + +long sys_clone(unsigned long flags, + std::nullptr_t child_stack, + pid_t* ptid, + pid_t* ctid, + std::nullptr_t tls) { + const bool clone_tls_used = flags & CLONE_SETTLS; + const bool invalid_ctid = + (flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) && !ctid; + const bool invalid_ptid = (flags & CLONE_PARENT_SETTID) && !ptid; + + // We do not support CLONE_VM. + const bool clone_vm_used = flags & CLONE_VM; + if (clone_tls_used || invalid_ctid || invalid_ptid || clone_vm_used) { + RAW_LOG(FATAL, "Invalid usage of sys_clone"); + } + + if (ptid) MSAN_UNPOISON(ptid, sizeof(*ptid)); + if (ctid) MSAN_UNPOISON(ctid, sizeof(*ctid)); + // See kernel/fork.c in Linux. There is different ordering of sys_clone + // parameters depending on CONFIG_CLONE_BACKWARDS* configuration options. +#if defined(ARCH_CPU_X86_64) + return syscall(__NR_clone, flags, child_stack, ptid, ctid, tls); +#elif defined(ARCH_CPU_X86) || defined(ARCH_CPU_ARM_FAMILY) || \ + defined(ARCH_CPU_MIPS_FAMILY) + // CONFIG_CLONE_BACKWARDS defined. + return syscall(__NR_clone, flags, child_stack, ptid, tls, ctid); +#endif +} + +long sys_clone(unsigned long flags) { + return sys_clone(flags, nullptr, nullptr, nullptr, nullptr); +} + +void sys_exit_group(int status) { + syscall(__NR_exit_group, status); +} + +int sys_seccomp(unsigned int operation, + unsigned int flags, + const struct sock_fprog* args) { + return syscall(__NR_seccomp, operation, flags, args); +} + +int sys_prlimit64(pid_t pid, + int resource, + const struct rlimit64* new_limit, + struct rlimit64* old_limit) { + int res = syscall(__NR_prlimit64, pid, resource, new_limit, old_limit); + if (res == 0 && old_limit) MSAN_UNPOISON(old_limit, sizeof(*old_limit)); + return res; +} + +int sys_capget(cap_hdr* hdrp, cap_data* datap) { + int res = syscall(__NR_capget, hdrp, datap); + if (res == 0) { + if (hdrp) MSAN_UNPOISON(hdrp, sizeof(*hdrp)); + if (datap) MSAN_UNPOISON(datap, sizeof(*datap)); + } + return res; +} + +int sys_capset(cap_hdr* hdrp, const cap_data* datap) { + return syscall(__NR_capset, hdrp, datap); +} + +int sys_getresuid(uid_t* ruid, uid_t* euid, uid_t* suid) { + int res; +#if defined(ARCH_CPU_X86) || defined(ARCH_CPU_ARMEL) + // On 32-bit x86 or 32-bit arm, getresuid supports 16bit values only. + // Use getresuid32 instead. + res = syscall(__NR_getresuid32, ruid, euid, suid); +#else + res = syscall(__NR_getresuid, ruid, euid, suid); +#endif + if (res == 0) { + if (ruid) MSAN_UNPOISON(ruid, sizeof(*ruid)); + if (euid) MSAN_UNPOISON(euid, sizeof(*euid)); + if (suid) MSAN_UNPOISON(suid, sizeof(*suid)); + } + return res; +} + +int sys_getresgid(gid_t* rgid, gid_t* egid, gid_t* sgid) { + int res; +#if defined(ARCH_CPU_X86) || defined(ARCH_CPU_ARMEL) + // On 32-bit x86 or 32-bit arm, getresgid supports 16bit values only. + // Use getresgid32 instead. + res = syscall(__NR_getresgid32, rgid, egid, sgid); +#else + res = syscall(__NR_getresgid, rgid, egid, sgid); +#endif + if (res == 0) { + if (rgid) MSAN_UNPOISON(rgid, sizeof(*rgid)); + if (egid) MSAN_UNPOISON(egid, sizeof(*egid)); + if (sgid) MSAN_UNPOISON(sgid, sizeof(*sgid)); + } + return res; +} + +int sys_chroot(const char* path) { + return syscall(__NR_chroot, path); +} + +int sys_unshare(int flags) { + return syscall(__NR_unshare, flags); +} + +int sys_sigprocmask(int how, const sigset_t* set, std::nullptr_t oldset) { + // In some toolchain (in particular Android and PNaCl toolchain), + // sigset_t is 32 bits, but the Linux ABI uses more. + LinuxSigSet linux_value; + std::memset(&linux_value, 0, sizeof(LinuxSigSet)); + std::memcpy(&linux_value, set, std::min(sizeof(sigset_t), + sizeof(LinuxSigSet))); + + return syscall(__NR_rt_sigprocmask, how, &linux_value, nullptr, + sizeof(linux_value)); +} + +// When this is built with PNaCl toolchain, we should always use sys_sigaction +// below, because sigaction() provided by the toolchain is incompatible with +// Linux's ABI. +#if !defined(OS_NACL_NONSFI) +int sys_sigaction(int signum, + const struct sigaction* act, + struct sigaction* oldact) { + return sigaction(signum, act, oldact); +} +#else +#if defined(ARCH_CPU_X86_FAMILY) + +// On x86_64, sa_restorer is required. We specify it on x86 as well in order to +// support kernels with VDSO disabled. +#if !defined(SA_RESTORER) +#define SA_RESTORER 0x04000000 +#endif + +// XSTR(__NR_foo) expands to a string literal containing the value value of +// __NR_foo. +#define STR(x) #x +#define XSTR(x) STR(x) + +// rt_sigreturn is a special system call that interacts with the user land +// stack. Thus, here prologue must not be created, which implies syscall() +// does not work properly, too. Note that rt_sigreturn does not return. +// TODO(rickyz): These assembly functions may still break stack unwinding on +// nonsfi NaCl builds. +#if defined(ARCH_CPU_X86_64) + +extern "C" { + void sys_rt_sigreturn(); +} + +asm( + ".text\n" + "sys_rt_sigreturn:\n" + "mov $" XSTR(__NR_rt_sigreturn) ", %eax\n" + "syscall\n"); + +#elif defined(ARCH_CPU_X86) +extern "C" { + void sys_sigreturn(); + void sys_rt_sigreturn(); +} + +asm( + ".text\n" + "sys_rt_sigreturn:\n" + "mov $" XSTR(__NR_rt_sigreturn) ", %eax\n" + "int $0x80\n" + + "sys_sigreturn:\n" + "pop %eax\n" + "mov $" XSTR(__NR_sigreturn) ", %eax\n" + "int $0x80\n"); +#else +#error "Unsupported architecture." +#endif + +#undef STR +#undef XSTR + +#endif + +int sys_sigaction(int signum, + const struct sigaction* act, + struct sigaction* oldact) { + LinuxSigAction linux_act = {}; + if (act) { + linux_act.kernel_handler = act->sa_handler; + std::memcpy(&linux_act.sa_mask, &act->sa_mask, + std::min(sizeof(linux_act.sa_mask), sizeof(act->sa_mask))); + linux_act.sa_flags = act->sa_flags; + +#if defined(ARCH_CPU_X86_FAMILY) + if (!(linux_act.sa_flags & SA_RESTORER)) { + linux_act.sa_flags |= SA_RESTORER; +#if defined(ARCH_CPU_X86_64) + linux_act.sa_restorer = sys_rt_sigreturn; +#elif defined(ARCH_CPU_X86) + linux_act.sa_restorer = + linux_act.sa_flags & SA_SIGINFO ? sys_rt_sigreturn : sys_sigreturn; +#else +#error "Unsupported architecture." +#endif + } +#endif + } + + LinuxSigAction linux_oldact = {}; + int result = syscall(__NR_rt_sigaction, signum, act ? &linux_act : nullptr, + oldact ? &linux_oldact : nullptr, + sizeof(LinuxSigSet)); + + if (result == 0 && oldact) { + oldact->sa_handler = linux_oldact.kernel_handler; + sigemptyset(&oldact->sa_mask); + std::memcpy(&oldact->sa_mask, &linux_oldact.sa_mask, + std::min(sizeof(linux_act.sa_mask), sizeof(act->sa_mask))); + oldact->sa_flags = linux_oldact.sa_flags; + } + return result; +} + +#endif // defined(MEMORY_SANITIZER) + +} // namespace sandbox |