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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-19 15:11:09 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-19 15:11:09 -0700
commitd471ce53b1fab60110e4e9f647a345cea31752de (patch)
tree73acb87c823b63d026f9ba4617b5e112835d6abf
parent1b050180454dc226780f765a33575d4cd8d6e552 (diff)
parent9e82d450531c79b18ab18c9b9645cdd9db31ee98 (diff)
downloadlinux-sh-d471ce53b1fab60110e4e9f647a345cea31752de.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML fixes from Richard Weinberger: "Special thanks goes to Toralf Föster for continuously testing UML and reporting issues!" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: remove dead code um: siginfo cleanup uml: Fix which_tmpdir failure when /dev/shm is a symlink, and in other edge cases um: Fix wait_stub_done() error handling um: Mark stub pages mapping with VM_PFNMAP um: Fix return value of strnlen_user()
-rw-r--r--arch/um/include/shared/frame_kern.h8
-rw-r--r--arch/um/kernel/signal.c4
-rw-r--r--arch/um/kernel/skas/mmu.c2
-rw-r--r--arch/um/kernel/skas/uaccess.c2
-rw-r--r--arch/um/os-Linux/mem.c230
-rw-r--r--arch/um/os-Linux/signal.c8
-rw-r--r--arch/um/os-Linux/skas/process.c19
-rw-r--r--arch/x86/um/signal.c1
8 files changed, 213 insertions, 61 deletions
diff --git a/arch/um/include/shared/frame_kern.h b/arch/um/include/shared/frame_kern.h
index e584e40ee832..f2ca5702a4e2 100644
--- a/arch/um/include/shared/frame_kern.h
+++ b/arch/um/include/shared/frame_kern.h
@@ -6,13 +6,13 @@
#ifndef __FRAME_KERN_H_
#define __FRAME_KERN_H_
-extern int setup_signal_stack_sc(unsigned long stack_top, int sig,
+extern int setup_signal_stack_sc(unsigned long stack_top, int sig,
struct k_sigaction *ka,
- struct pt_regs *regs,
+ struct pt_regs *regs,
sigset_t *mask);
-extern int setup_signal_stack_si(unsigned long stack_top, int sig,
+extern int setup_signal_stack_si(unsigned long stack_top, int sig,
struct k_sigaction *ka,
- struct pt_regs *regs, siginfo_t *info,
+ struct pt_regs *regs, struct siginfo *info,
sigset_t *mask);
#endif
diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
index 3e831b3fd07b..f57e02e7910f 100644
--- a/arch/um/kernel/signal.c
+++ b/arch/um/kernel/signal.c
@@ -19,7 +19,7 @@ EXPORT_SYMBOL(unblock_signals);
* OK, we're invoking a handler
*/
static void handle_signal(struct pt_regs *regs, unsigned long signr,
- struct k_sigaction *ka, siginfo_t *info)
+ struct k_sigaction *ka, struct siginfo *info)
{
sigset_t *oldset = sigmask_to_save();
int singlestep = 0;
@@ -71,7 +71,7 @@ static void handle_signal(struct pt_regs *regs, unsigned long signr,
static int kern_do_signal(struct pt_regs *regs)
{
struct k_sigaction ka_copy;
- siginfo_t info;
+ struct siginfo info;
int sig, handled_sig = 0;
while ((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0) {
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index ff03067a3b14..007d5503f49b 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -123,7 +123,7 @@ void uml_setup_stubs(struct mm_struct *mm)
/* dup_mmap already holds mmap_sem */
err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START,
VM_READ | VM_MAYREAD | VM_EXEC |
- VM_MAYEXEC | VM_DONTCOPY,
+ VM_MAYEXEC | VM_DONTCOPY | VM_PFNMAP,
mm->context.stub_pages);
if (err) {
printk(KERN_ERR "install_special_mapping returned %d\n", err);
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index 1d3e0c17340b..4ffb644d6c07 100644
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -254,6 +254,6 @@ int strnlen_user(const void __user *str, int len)
n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count);
if (n == 0)
return count + 1;
- return -EFAULT;
+ return 0;
}
EXPORT_SYMBOL(strnlen_user);
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/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,
&regs->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/x86/um/signal.c b/arch/x86/um/signal.c
index ae7319db18ee..5e04a1c899fa 100644
--- a/arch/x86/um/signal.c
+++ b/arch/x86/um/signal.c
@@ -508,7 +508,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
{
struct rt_sigframe __user *frame;
int err = 0;
- struct task_struct *me = current;
frame = (struct rt_sigframe __user *)
round_down(stack_top - sizeof(struct rt_sigframe), 16);