https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=2607639992f6600135532831c8357c10cb248821
commit 2607639992f6600135532831c8357c10cb248821 Author: Erik M. Bray <[email protected]> Date: Wed Apr 10 17:05:22 2019 +0200 Improve error handling in /proc/[pid]/ virtual files. * Changes error handling to allow /proc/[pid]/ virtual files to be empty in some cases (in this case the file's formatter should return -1 upon error, not 0). * Better error handling of /proc/[pid]/stat for zombie processes: previously trying to open this file on zombie processes resulted in an EINVAL being returned by open(). Now the file can be read, and fields that can no longer be read are just zeroed. * Similarly for /proc/[pid]/statm for zombie processes. * Similarly for /proc/[pid]/maps for zombie processes (in this case the file can be read but is zero-length, which is consistent with observed behavior on Linux. Diff: --- winsup/cygwin/fhandler_process.cc | 35 ++++++++++++++++++++++++++++------- 1 file changed, 28 insertions(+), 7 deletions(-) diff --git a/winsup/cygwin/fhandler_process.cc b/winsup/cygwin/fhandler_process.cc index 44410b2..5ee1293 100644 --- a/winsup/cygwin/fhandler_process.cc +++ b/winsup/cygwin/fhandler_process.cc @@ -355,7 +355,7 @@ fhandler_process::fill_filebuf () } else filesize = process_tab[fileid].format_func (p, filebuf); - return !filesize ? false : true; + return filesize < 0 ? false : true; } return false; } @@ -818,7 +818,22 @@ format_process_maps (void *data, char *&destbuf) HANDLE proc = OpenProcess (PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, p->dwProcessId); if (!proc) - return 0; + { + if (!(p->process_state & PID_EXITED)) + { + DWORD error = GetLastError (); + __seterrno_from_win_error (error); + debug_printf ("OpenProcess: ret %u; pid: %d", error, p->dwProcessId); + return -1; + } + else + { + /* Else it's a zombie process; just return an empty string */ + destbuf = (char *) crealloc_abort (destbuf, 1); + destbuf[0] = '\0'; + return 0; + } + } NTSTATUS status; PROCESS_BASIC_INFORMATION pbi; @@ -1101,9 +1116,14 @@ format_process_stat (void *data, char *&destbuf) FALSE, p->dwProcessId); if (hProcess == NULL) { - DWORD error = GetLastError (); - __seterrno_from_win_error (error); - debug_printf ("OpenProcess: ret %u", error); + if (!(p->process_state & PID_EXITED)) + { + DWORD error = GetLastError (); + __seterrno_from_win_error (error); + debug_printf ("OpenProcess: ret %u; pid: %d", error, p->dwProcessId); + return -1; + } + /* Else it's a zombie process; just leave each structure zero'd */ } else { @@ -1258,9 +1278,10 @@ format_process_statm (void *data, char *&destbuf) { _pinfo *p = (_pinfo *) data; size_t vmsize = 0, vmrss = 0, vmtext = 0, vmdata = 0, vmlib = 0, vmshare = 0; + if (!get_mem_values (p->dwProcessId, vmsize, vmrss, vmtext, vmdata, - vmlib, vmshare)) - return 0; + vmlib, vmshare) && !(p->process_state & PID_EXITED)) + return -1; /* Error out unless it's a zombie process */ destbuf = (char *) crealloc_abort (destbuf, 96); return __small_sprintf (destbuf, "%lu %lu %lu %lu %lu %lu 0\n",
