diff options
Diffstat (limited to 'arch/um/os-Linux')
-rw-r--r-- | arch/um/os-Linux/aio.c | 5 | ||||
-rw-r--r-- | arch/um/os-Linux/file.c | 9 | ||||
-rw-r--r-- | arch/um/os-Linux/main.c | 2 | ||||
-rw-r--r-- | arch/um/os-Linux/mem.c | 230 | ||||
-rw-r--r-- | arch/um/os-Linux/process.c | 53 | ||||
-rw-r--r-- | arch/um/os-Linux/sigio.c | 2 | ||||
-rw-r--r-- | arch/um/os-Linux/signal.c | 8 | ||||
-rw-r--r-- | arch/um/os-Linux/skas/process.c | 19 | ||||
-rw-r--r-- | arch/um/os-Linux/util.c | 10 |
9 files changed, 281 insertions, 57 deletions
diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c index 3a6bc2af0961..014eb35fd13b 100644 --- a/arch/um/os-Linux/aio.c +++ b/arch/um/os-Linux/aio.c @@ -104,8 +104,7 @@ static int aio_thread(void *arg) struct io_event event; int err, n, reply_fd; - signal(SIGWINCH, SIG_IGN); - + os_fix_helper_signals(); while (1) { n = io_getevents(ctx, 1, 1, &event, NULL); if (n < 0) { @@ -173,7 +172,7 @@ static int not_aio_thread(void *arg) struct aio_thread_reply reply; int err; - signal(SIGWINCH, SIG_IGN); + os_fix_helper_signals(); while (1) { err = read(aio_req_fd_r, &req, sizeof(req)); if (err != sizeof(req)) { diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c index c17bd6f7d674..07a750197bb0 100644 --- a/arch/um/os-Linux/file.c +++ b/arch/um/os-Linux/file.c @@ -266,6 +266,15 @@ int os_write_file(int fd, const void *buf, int len) return n; } +int os_sync_file(int fd) +{ + int n = fsync(fd); + + if (n < 0) + return -errno; + return n; +} + int os_file_size(const char *file, unsigned long long *size_out) { struct uml_stat buf; diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c index 749c96da7b99..e1704ff600ff 100644 --- a/arch/um/os-Linux/main.c +++ b/arch/um/os-Linux/main.c @@ -123,6 +123,8 @@ int __init main(int argc, char **argv, char **envp) setup_env_path(); + setsid(); + new_argv = malloc((argc + 1) * sizeof(char *)); if (new_argv == NULL) { perror("Mallocing argv"); diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c index ba4398056fe9..3c4af77e51a2 100644 --- a/arch/um/os-Linux/mem.c +++ b/arch/um/os-Linux/mem.c @@ -53,6 +53,25 @@ static void __init find_tempdir(void) } /* + * Remove bytes from the front of the buffer and refill it so that if there's a + * partial string that we care about, it will be completed, and we can recognize + * it. + */ +static int pop(int fd, char *buf, size_t size, size_t npop) +{ + ssize_t n; + size_t len = strlen(&buf[npop]); + + memmove(buf, &buf[npop], len + 1); + n = read(fd, &buf[len], size - len - 1); + if (n < 0) + return -errno; + + buf[len + n] = '\0'; + return 1; +} + +/* * This will return 1, with the first character in buf being the * character following the next instance of c in the file. This will * read the file as needed. If there's an error, -errno is returned; @@ -61,7 +80,6 @@ static void __init find_tempdir(void) static int next(int fd, char *buf, size_t size, char c) { ssize_t n; - size_t len; char *ptr; while ((ptr = strchr(buf, c)) == NULL) { @@ -74,20 +92,129 @@ static int next(int fd, char *buf, size_t size, char c) buf[n] = '\0'; } - ptr++; - len = strlen(ptr); - memmove(buf, ptr, len + 1); + return pop(fd, buf, size, ptr - buf + 1); +} + +/* + * Decode an octal-escaped and space-terminated path of the form used by + * /proc/mounts. May be used to decode a path in-place. "out" must be at least + * as large as the input. The output is always null-terminated. "len" gets the + * length of the output, excluding the trailing null. Returns 0 if a full path + * was successfully decoded, otherwise an error. + */ +static int decode_path(const char *in, char *out, size_t *len) +{ + char *first = out; + int c; + int i; + int ret = -EINVAL; + while (1) { + switch (*in) { + case '\0': + goto out; + + case ' ': + ret = 0; + goto out; + + case '\\': + in++; + c = 0; + for (i = 0; i < 3; i++) { + if (*in < '0' || *in > '7') + goto out; + c = (c << 3) | (*in++ - '0'); + } + *(unsigned char *)out++ = (unsigned char) c; + break; + + default: + *out++ = *in++; + break; + } + } + +out: + *out = '\0'; + *len = out - first; + return ret; +} + +/* + * Computes the length of s when encoded with three-digit octal escape sequences + * for the characters in chars. + */ +static size_t octal_encoded_length(const char *s, const char *chars) +{ + size_t len = strlen(s); + while ((s = strpbrk(s, chars)) != NULL) { + len += 3; + s++; + } + + return len; +} + +enum { + OUTCOME_NOTHING_MOUNTED, + OUTCOME_TMPFS_MOUNT, + OUTCOME_NON_TMPFS_MOUNT, +}; + +/* Read a line of /proc/mounts data looking for a tmpfs mount at "path". */ +static int read_mount(int fd, char *buf, size_t bufsize, const char *path, + int *outcome) +{ + int found; + int match; + char *space; + size_t len; + + enum { + MATCH_NONE, + MATCH_EXACT, + MATCH_PARENT, + }; + + found = next(fd, buf, bufsize, ' '); + if (found != 1) + return found; /* - * Refill the buffer so that if there's a partial string that we care - * about, it will be completed, and we can recognize it. + * If there's no following space in the buffer, then this path is + * truncated, so it can't be the one we're looking for. */ - n = read(fd, &buf[len], size - len - 1); - if (n < 0) - return -errno; + space = strchr(buf, ' '); + if (space) { + match = MATCH_NONE; + if (!decode_path(buf, buf, &len)) { + if (!strcmp(buf, path)) + match = MATCH_EXACT; + else if (!strncmp(buf, path, len) + && (path[len] == '/' || !strcmp(buf, "/"))) + match = MATCH_PARENT; + } + + found = pop(fd, buf, bufsize, space - buf + 1); + if (found != 1) + return found; + + switch (match) { + case MATCH_EXACT: + if (!strncmp(buf, "tmpfs", strlen("tmpfs"))) + *outcome = OUTCOME_TMPFS_MOUNT; + else + *outcome = OUTCOME_NON_TMPFS_MOUNT; + break; - buf[len + n] = '\0'; - return 1; + case MATCH_PARENT: + /* This mount obscures any previous ones. */ + *outcome = OUTCOME_NOTHING_MOUNTED; + break; + } + } + + return next(fd, buf, bufsize, '\n'); } /* which_tmpdir is called only during early boot */ @@ -106,8 +233,12 @@ static int checked_tmpdir = 0; */ static void which_tmpdir(void) { - int fd, found; - char buf[128] = { '\0' }; + int fd; + int found; + int outcome; + char *path; + char *buf; + size_t bufsize; if (checked_tmpdir) return; @@ -116,49 +247,66 @@ static void which_tmpdir(void) printf("Checking for tmpfs mount on /dev/shm..."); + path = realpath("/dev/shm", NULL); + if (!path) { + printf("failed to check real path, errno = %d\n", errno); + return; + } + printf("%s...", path); + + /* + * The buffer needs to be able to fit the full octal-escaped path, a + * space, and a trailing null in order to successfully decode it. + */ + bufsize = octal_encoded_length(path, " \t\n\\") + 2; + + if (bufsize < 128) + bufsize = 128; + + buf = malloc(bufsize); + if (!buf) { + printf("malloc failed, errno = %d\n", errno); + goto out; + } + buf[0] = '\0'; + fd = open("/proc/mounts", O_RDONLY); if (fd < 0) { printf("failed to open /proc/mounts, errno = %d\n", errno); - return; + goto out1; } + outcome = OUTCOME_NOTHING_MOUNTED; while (1) { - found = next(fd, buf, ARRAY_SIZE(buf), ' '); - if (found != 1) - break; - - if (!strncmp(buf, "/dev/shm", strlen("/dev/shm"))) - goto found; - - found = next(fd, buf, ARRAY_SIZE(buf), '\n'); + found = read_mount(fd, buf, bufsize, path, &outcome); if (found != 1) break; } -err: - if (found == 0) - printf("nothing mounted on /dev/shm\n"); - else if (found < 0) + if (found < 0) { printf("read returned errno %d\n", -found); + } else { + switch (outcome) { + case OUTCOME_TMPFS_MOUNT: + printf("OK\n"); + default_tmpdir = "/dev/shm"; + break; -out: - close(fd); - - return; - -found: - found = next(fd, buf, ARRAY_SIZE(buf), ' '); - if (found != 1) - goto err; + case OUTCOME_NON_TMPFS_MOUNT: + printf("not tmpfs\n"); + break; - if (strncmp(buf, "tmpfs", strlen("tmpfs"))) { - printf("not tmpfs\n"); - goto out; + default: + printf("nothing mounted on /dev/shm\n"); + break; + } } - printf("OK\n"); - default_tmpdir = "/dev/shm"; - goto out; + close(fd); +out1: + free(buf); +out: + free(path); } static int __init make_tempfile(const char *template, char **out_tempname, diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c index b8f34c9e53ae..33496fe2bb52 100644 --- a/arch/um/os-Linux/process.c +++ b/arch/um/os-Linux/process.c @@ -4,6 +4,7 @@ */ #include <stdio.h> +#include <stdlib.h> #include <unistd.h> #include <errno.h> #include <signal.h> @@ -232,6 +233,57 @@ out: return ok; } +static int os_page_mincore(void *addr) +{ + char vec[2]; + int ret; + + ret = mincore(addr, UM_KERN_PAGE_SIZE, vec); + if (ret < 0) { + if (errno == ENOMEM || errno == EINVAL) + return 0; + else + return -errno; + } + + return vec[0] & 1; +} + +int os_mincore(void *addr, unsigned long len) +{ + char *vec; + int ret, i; + + if (len <= UM_KERN_PAGE_SIZE) + return os_page_mincore(addr); + + vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); + if (!vec) + return -ENOMEM; + + ret = mincore(addr, UM_KERN_PAGE_SIZE, vec); + if (ret < 0) { + if (errno == ENOMEM || errno == EINVAL) + ret = 0; + else + ret = -errno; + + goto out; + } + + for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) { + if (!(vec[i] & 1)) { + ret = 0; + goto out; + } + } + + ret = 1; +out: + free(vec); + return ret; +} + void init_new_thread_signals(void) { set_handler(SIGSEGV); @@ -242,5 +294,4 @@ void init_new_thread_signals(void) signal(SIGHUP, SIG_IGN); set_handler(SIGIO); signal(SIGWINCH, SIG_IGN); - signal(SIGTERM, SIG_DFL); } diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c index 8b61cc0e82c8..46e762f926eb 100644 --- a/arch/um/os-Linux/sigio.c +++ b/arch/um/os-Linux/sigio.c @@ -55,7 +55,7 @@ static int write_sigio_thread(void *unused) int i, n, respond_fd; char c; - signal(SIGWINCH, SIG_IGN); + os_fix_helper_signals(); fds = ¤t_poll; while (1) { n = poll(fds->poll, fds->used, -1); diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c index 9d9f1b4bf826..905924b773d3 100644 --- a/arch/um/os-Linux/signal.c +++ b/arch/um/os-Linux/signal.c @@ -25,7 +25,7 @@ void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = { [SIGIO] = sigio_handler, [SIGVTALRM] = timer_handler }; -static void sig_handler_common(int sig, siginfo_t *si, mcontext_t *mc) +static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) { struct uml_pt_regs r; int save_errno = errno; @@ -61,7 +61,7 @@ static void sig_handler_common(int sig, siginfo_t *si, mcontext_t *mc) static int signals_enabled; static unsigned int signals_pending; -void sig_handler(int sig, siginfo_t *si, mcontext_t *mc) +void sig_handler(int sig, struct siginfo *si, mcontext_t *mc) { int enabled; @@ -120,7 +120,7 @@ void set_sigstack(void *sig_stack, int size) panic("enabling signal stack failed, errno = %d\n", errno); } -static void (*handlers[_NSIG])(int sig, siginfo_t *si, mcontext_t *mc) = { +static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = { [SIGSEGV] = sig_handler, [SIGBUS] = sig_handler, [SIGILL] = sig_handler, @@ -162,7 +162,7 @@ static void hard_handler(int sig, siginfo_t *si, void *p) while ((sig = ffs(pending)) != 0){ sig--; pending &= ~(1 << sig); - (*handlers[sig])(sig, si, mc); + (*handlers[sig])(sig, (struct siginfo *)si, mc); } /* diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 4625949bf1e4..d531879a4617 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -54,7 +54,7 @@ static int ptrace_dump_regs(int pid) void wait_stub_done(int pid) { - int n, status, err; + int n, status, err, bad_stop = 0; while (1) { CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL)); @@ -74,6 +74,8 @@ void wait_stub_done(int pid) if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0) return; + else + bad_stop = 1; bad_wait: err = ptrace_dump_regs(pid); @@ -83,7 +85,10 @@ bad_wait: printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, " "pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno, status); - fatal_sigsegv(); + if (bad_stop) + kill(pid, SIGKILL); + else + fatal_sigsegv(); } extern unsigned long current_stub_stack(void); @@ -409,7 +414,7 @@ void userspace(struct uml_pt_regs *regs) if (WIFSTOPPED(status)) { int sig = WSTOPSIG(status); - ptrace(PTRACE_GETSIGINFO, pid, 0, &si); + ptrace(PTRACE_GETSIGINFO, pid, 0, (struct siginfo *)&si); switch (sig) { case SIGSEGV: @@ -417,7 +422,7 @@ void userspace(struct uml_pt_regs *regs) !ptrace_faultinfo) { get_skas_faultinfo(pid, ®s->faultinfo); - (*sig_info[SIGSEGV])(SIGSEGV, &si, + (*sig_info[SIGSEGV])(SIGSEGV, (struct siginfo *)&si, regs); } else handle_segv(pid, regs); @@ -426,14 +431,14 @@ void userspace(struct uml_pt_regs *regs) handle_trap(pid, regs, local_using_sysemu); break; case SIGTRAP: - relay_signal(SIGTRAP, &si, regs); + relay_signal(SIGTRAP, (struct siginfo *)&si, regs); break; case SIGVTALRM: now = os_nsecs(); if (now < nsecs) break; block_signals(); - (*sig_info[sig])(sig, &si, regs); + (*sig_info[sig])(sig, (struct siginfo *)&si, regs); unblock_signals(); nsecs = timer.it_value.tv_sec * UM_NSEC_PER_SEC + @@ -447,7 +452,7 @@ void userspace(struct uml_pt_regs *regs) case SIGFPE: case SIGWINCH: block_signals(); - (*sig_info[sig])(sig, &si, regs); + (*sig_info[sig])(sig, (struct siginfo *)&si, regs); unblock_signals(); break; default: diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c index 492ef5e6e166..faee55ef6d2f 100644 --- a/arch/um/os-Linux/util.c +++ b/arch/um/os-Linux/util.c @@ -94,6 +94,16 @@ static inline void __attribute__ ((noreturn)) uml_abort(void) exit(127); } +/* + * UML helper threads must not handle SIGWINCH/INT/TERM + */ +void os_fix_helper_signals(void) +{ + signal(SIGWINCH, SIG_IGN); + signal(SIGINT, SIG_DFL); + signal(SIGTERM, SIG_DFL); +} + void os_dump_core(void) { int pid; 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