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author | Erik M. Bray <erik.m.bray@gmail.com> | 2019-04-10 17:05:22 +0200 |
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committer | Corinna Vinschen <corinna@vinschen.de> | 2019-04-10 18:17:14 +0200 |
commit | 2607639992f6600135532831c8357c10cb248821 (patch) | |
tree | 5df11d1027524da0594990c35513893f927a4ad5 | |
parent | f0ea836b753b0756b00866ac8b909a0a7dfbac5f (diff) | |
download | newlib-2607639992f6600135532831c8357c10cb248821.zip newlib-2607639992f6600135532831c8357c10cb248821.tar.gz newlib-2607639992f6600135532831c8357c10cb248821.tar.bz2 |
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.
-rw-r--r-- | winsup/cygwin/fhandler_process.cc | 35 |
1 files 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", |