On Fri, 10 Apr 2020, 12:11 Philippe Mathieu-Daudé, <address@hidden
<mailto:address@hidden>> wrote:
Cc'ing Ludovic in case he can test with Guix-HPC.
On 4/9/20 11:15 PM, Alex Bennée wrote:
> In the original bug report long files names in Guix caused
> /proc/self/stat be truncated without the trailing ") " as
specified in
> proc manpage which says:
> (2) comm %s
> The filename of the executable, in parentheses. This
> is visible whether or not the executable is swapped
> out.
>
> Additionally it should only be reporting the executable name rather
> than the full path. Fix both these failings while cleaning up the
code
> to use GString to build up the reported values. As the whole function
> is cleaned up also adjust the white space to the current coding
style.
>
> Message-ID: <address@hidden
<mailto:address@hidden>>
> Reported-by: Brice Goglin <address@hidden
<mailto:address@hidden>>
> Cc: Philippe_Mathieu-Daudé <address@hidden
<mailto:address@hidden>>
> Signed-off-by: Alex Bennée <address@hidden
<mailto:address@hidden>>
> ---
> linux-user/syscall.c | 43
+++++++++++++++++++------------------------
> 1 file changed, 19 insertions(+), 24 deletions(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 6495ddc4cda..674f70e70a5 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -7295,34 +7295,29 @@ static int open_self_stat(void *cpu_env,
int fd)
> {
> CPUState *cpu = env_cpu((CPUArchState *)cpu_env);
> TaskState *ts = cpu->opaque;
> - abi_ulong start_stack = ts->info->start_stack;
> + g_autoptr(GString) buf = g_string_new(NULL);
> int i;
>
> for (i = 0; i < 44; i++) {
> - char buf[128];
> - int len;
> - uint64_t val = 0;
> -
> - if (i == 0) {
> - /* pid */
> - val = getpid();
> - snprintf(buf, sizeof(buf), "%"PRId64 " ", val);
> - } else if (i == 1) {
> - /* app name */
> - snprintf(buf, sizeof(buf), "(%s) ", ts->bprm->argv[0]);
> - } else if (i == 27) {
> - /* stack bottom */
> - val = start_stack;
> - snprintf(buf, sizeof(buf), "%"PRId64 " ", val);
> - } else {
> - /* for the rest, there is MasterCard */
> - snprintf(buf, sizeof(buf), "0%c", i == 43 ? '\n' : ' ');
> - }
> + if (i == 0) {
> + /* pid */
> + g_string_printf(buf, FMT_pid " ", getpid());
> + } else if (i == 1) {
> + /* app name */
> + gchar *bin = g_strrstr(ts->bprm->argv[0], "/");
> + bin = bin ? bin + 1 : ts->bprm->argv[0];
> + g_string_printf(buf, "(%.15s) ", bin);
15 or 125? 15 seems short. From your previous test I understood it was
124, for
sizeof("cat_with9_12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890___40").
> + } else if (i == 27) {
> + /* stack bottom */
> + g_string_printf(buf, TARGET_ABI_FMT_ld " ",
ts->info->start_stack);
> + } else {
> + /* for the rest, there is MasterCard */
> + g_string_printf(buf, "0%c", i == 43 ? '\n' : ' ');
> + }
>
> - len = strlen(buf);
> - if (write(fd, buf, len) != len) {
> - return -1;
> - }
> + if (write(fd, buf->str, buf->len) != buf->len) {
> + return -1;
> + }
> }
>
> return 0;
>