Le 12/05/2016 à 19:47, Peter Maydell a écrit :
> The function do_openat() is not consistent about whether it is
> returning a host errno or a guest errno in case of failure.
> Standardise on returning -1 with errno set (ie caller has
> to call get_errno()).
>
> Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
> Reported-by: Timothy Edward Baldwin <t.e.baldwi...@members.leeds.ac.uk>
Reviewed-by: Laurent Vivier <laur...@vivier.eu>
> ---
> Timothy's patchset for fixing signal races had a patch which also
> addressed this bug. However I preferred to take the opposite tack
> and have the callers do get_errno() rather than the callee, because
> it means changes in fewer places and it's generally more natural
> for the 'fill' functions that do_openat() calls.
> ---
> linux-user/syscall.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 5246f36..f4c2e19 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -5559,7 +5559,9 @@ static int open_self_cmdline(void *cpu_env, int fd)
>
> nb_read = read(fd_orig, buf, sizeof(buf));
> if (nb_read < 0) {
> + int e = errno;
> fd_orig = close(fd_orig);
> + errno = e;
> return -1;
> } else if (nb_read == 0) {
> break;
> @@ -5579,7 +5581,9 @@ static int open_self_cmdline(void *cpu_env, int fd)
>
> if (word_skipped) {
> if (write(fd, cp_buf, nb_read) != nb_read) {
> + int e = errno;
> close(fd_orig);
> + errno = e;
> return -1;
> }
> }
> @@ -5599,7 +5603,7 @@ static int open_self_maps(void *cpu_env, int fd)
>
> fp = fopen("/proc/self/maps", "r");
> if (fp == NULL) {
> - return -EACCES;
> + return -1;
> }
>
> while ((read = getline(&line, &len, fp)) != -1) {
> @@ -5743,7 +5747,7 @@ static int open_net_route(void *cpu_env, int fd)
>
> fp = fopen("/proc/net/route", "r");
> if (fp == NULL) {
> - return -EACCES;
> + return -1;
> }
>
> /* read header */
> @@ -5793,7 +5797,7 @@ static int do_openat(void *cpu_env, int dirfd, const
> char *pathname, int flags,
>
> if (is_proc_myself(pathname, "exe")) {
> int execfd = qemu_getauxval(AT_EXECFD);
> - return execfd ? execfd : get_errno(sys_openat(dirfd, exec_path,
> flags, mode));
> + return execfd ? execfd : sys_openat(dirfd, exec_path, flags, mode);
> }
>
> for (fake_open = fakes; fake_open->filename; fake_open++) {
> @@ -5819,7 +5823,9 @@ static int do_openat(void *cpu_env, int dirfd, const
> char *pathname, int flags,
> unlink(filename);
>
> if ((r = fake_open->fill(cpu_env, fd))) {
> + int e = errno;
> close(fd);
> + errno = e;
> return r;
> }
> lseek(fd, 0, SEEK_SET);
> @@ -5827,7 +5833,7 @@ static int do_openat(void *cpu_env, int dirfd, const
> char *pathname, int flags,
> return fd;
> }
>
> - return get_errno(sys_openat(dirfd, path(pathname), flags, mode));
> + return sys_openat(dirfd, path(pathname), flags, mode);
> }
>
> #define TIMER_MAGIC 0x0caf0000
>
