# HG changeset patch # User Maxim Dounin # Date 1614618043 -10800 # Node ID 8cc5b0365ee5e6209480cdf47f10187ee9c33e1e # Parent 171682010da4f18fbdc92bfec9e28674e4a61125 Improved maximum errno detection. Previously, systems without sys_nerr (or _sys_nerr) were handled with an assumption that errors start at 0 and continuous. This is, however, not something POSIX requires, and not true on some platforms. Notably, on Linux, where sys_nerr is no longer available for newly linked binaries starting with glibc 2.32, there are gaps in error list, which used to stop us from properly detecting maximum errno. Further, on GNU/Hurd errors start at 0x40000001. With this change, maximum errno detection is moved to the runtime code, now able to ignore gaps, and also detects the first error if needed. This fixes observed "Unknown error" messages as seen on Linux with glibc 2.32 and on GNU/Hurd. diff --git a/auto/unix b/auto/unix --- a/auto/unix +++ b/auto/unix @@ -753,34 +753,6 @@ if [ $ngx_found = no ]; then fi -if [ $ngx_found = no ]; then - - # Solaris has no sys_nerr - ngx_feature='maximum errno' - ngx_feature_name=NGX_SYS_NERR - ngx_feature_run=value - ngx_feature_incs='#include - #include - #include ' - ngx_feature_path= - ngx_feature_libs= - ngx_feature_test='int n; - char *p; - for (n = 1; n < 1000; n++) { - errno = 0; - p = strerror(n); - if (errno == EINVAL - || p == NULL - || strncmp(p, "Unknown error", 13) == 0) - { - break; - } - } - printf("%d", n);' - . auto/feature -fi - - ngx_feature="localtime_r()" ngx_feature_name="NGX_HAVE_LOCALTIME_R" ngx_feature_run=no diff --git a/src/os/unix/ngx_errno.c b/src/os/unix/ngx_errno.c --- a/src/os/unix/ngx_errno.c +++ b/src/os/unix/ngx_errno.c @@ -27,6 +27,8 @@ static ngx_str_t *ngx_sys_errlist; static ngx_str_t ngx_unknown_error = ngx_string("Unknown error"); +static ngx_err_t ngx_first_error; +static ngx_err_t ngx_last_error; u_char * @@ -34,8 +36,13 @@ ngx_strerror(ngx_err_t err, u_char *errs { ngx_str_t *msg; - msg = ((ngx_uint_t) err < NGX_SYS_NERR) ? &ngx_sys_errlist[err]: - &ngx_unknown_error; + if (err >= ngx_first_error && err < ngx_last_error) { + msg = &ngx_sys_errlist[err - ngx_first_error]; + + } else { + msg = &ngx_unknown_error; + } + size = ngx_min(size, msg->len); return ngx_cpymem(errstr, msg->data, size); @@ -50,20 +57,92 @@ ngx_strerror_init(void) size_t len; ngx_err_t err; +#if (NGX_SYS_NERR) + ngx_first_error = 0; + ngx_last_error = NGX_SYS_NERR; + +#elif (EPERM > 1000 && EPERM < 0x7fffffff - 1000) + + /* + * If number of errors is not known, and EPERM error code has large + * but reasonable value, guess possible error codes based on the error + * messages returned by strerror(), starting from EPERM. Notably, + * this covers GNU/Hurd, where errors start at 0x40000001. + */ + + for (err = EPERM; err > EPERM - 1000; err--) { + ngx_set_errno(0); + msg = strerror(err); + + if (errno == EINVAL + || msg == NULL + || strncmp(msg, "Unknown error", 13) == 0) + { + continue; + } + + ngx_first_error = err; + } + + for (err = EPERM; err < EPERM + 1000; err++) { + ngx_set_errno(0); + msg = strerror(err); + + if (errno == EINVAL + || msg == NULL + || strncmp(msg, "Unknown error", 13) == 0) + { + continue; + } + + ngx_last_error = err + 1; + } + +#else + + /* + * If number of errors is not known, guess it based on the error + * messages returned by strerror(). + */ + + ngx_first_error = 0; + + for (err = 0; err < 1000; err++) { + ngx_set_errno(0); + msg = strerror(err); + + if (errno == EINVAL + || msg == NULL + || strncmp(msg, "Unknown error", 13) == 0) + { + continue; + } + + ngx_last_error = err + 1; + } + +#endif + /* * ngx_strerror() is not ready to work at this stage, therefore, * malloc() is used and possible errors are logged using strerror(). */ - len = NGX_SYS_NERR * sizeof(ngx_str_t); + len = (ngx_last_error - ngx_first_error) * sizeof(ngx_str_t); ngx_sys_errlist = malloc(len); if (ngx_sys_errlist == NULL) { goto failed; } - for (err = 0; err < NGX_SYS_NERR; err++) { + for (err = ngx_first_error; err < ngx_last_error; err++) { msg = strerror(err); + + if (msg == NULL) { + ngx_sys_errlist[err - ngx_first_error] = ngx_unknown_error; + continue; + } + len = ngx_strlen(msg); p = malloc(len); @@ -72,8 +151,8 @@ ngx_strerror_init(void) } ngx_memcpy(p, msg, len); - ngx_sys_errlist[err].len = len; - ngx_sys_errlist[err].data = p; + ngx_sys_errlist[err - ngx_first_error].len = len; + ngx_sys_errlist[err - ngx_first_error].data = p; } return NGX_OK;