diff options
Diffstat (limited to 'winsup/cygwin')
| -rw-r--r-- | winsup/cygwin/Makefile.in | 1 | ||||
| -rw-r--r-- | winsup/cygwin/dll_init.cc | 18 | ||||
| -rw-r--r-- | winsup/cygwin/dll_init.h | 50 | ||||
| -rw-r--r-- | winsup/cygwin/fork.cc | 21 | ||||
| -rw-r--r-- | winsup/cygwin/forkable.cc | 1095 | ||||
| -rw-r--r-- | winsup/cygwin/pinfo.cc | 3 | ||||
| -rw-r--r-- | winsup/cygwin/syscalls.cc | 24 |
7 files changed, 1207 insertions, 5 deletions
diff --git a/winsup/cygwin/Makefile.in b/winsup/cygwin/Makefile.in index c14eea3..b687d92 100644 --- a/winsup/cygwin/Makefile.in +++ b/winsup/cygwin/Makefile.in @@ -313,6 +313,7 @@ DLL_OFILES:= \ flock.o \ fnmatch.o \ fork.o \ + forkable.o \ fts.o \ ftw.o \ getentropy.o \ diff --git a/winsup/cygwin/dll_init.cc b/winsup/cygwin/dll_init.cc index 2204533..90b3940 100644 --- a/winsup/cygwin/dll_init.cc +++ b/winsup/cygwin/dll_init.cc @@ -300,6 +300,7 @@ dll_list::alloc (HINSTANCE h, per_process *p, dll_type type) PWCHAR ntname = nt_max_path_buf (); GetModuleFileNameW (h, ntname, NT_MAX_PATH); PWCHAR modname = form_ntname (ntname, NT_MAX_PATH, ntname); + DWORD ntnamelen = modname - ntname; while (modname > ntname && *(modname - 1) != L'\\') --modname; @@ -334,6 +335,12 @@ dll_list::alloc (HINSTANCE h, per_process *p, dll_type type) } else { + size_t forkntsize = forkable_ntnamesize (type, ntname, modname); + + /* FIXME: Change this to new at some point. */ + d = (dll *) cmalloc (HEAP_2_DLL, sizeof (*d) + + ((ntnamelen + forkntsize) * sizeof (*ntname))); + /* Now we've allocated a block of information. Fill it in with the supplied info about this DLL. */ wcscpy (d->ntname, ntname); @@ -348,6 +355,15 @@ dll_list::alloc (HINSTANCE h, per_process *p, dll_type type) d->image_size = ((pefile*)h)->optional_hdr ()->SizeOfImage; d->preferred_base = (void*) ((pefile*)h)->optional_hdr()->ImageBase; d->type = type; + d->fbi.FileAttributes = INVALID_FILE_ATTRIBUTES; + d->fii.IndexNumber.QuadPart = -1LL; + if (!forkntsize) + d->forkable_ntname = NULL; + else + { + d->forkable_ntname = d->ntname + ntnamelen + 1; + *d->forkable_ntname = L'\0'; + } append (d); if (type == DLL_LOAD) loaded_dlls++; @@ -654,6 +670,8 @@ dll_list::reserve_space () void dll_list::load_after_fork (HANDLE parent) { + release_forkables (); + // moved to frok::child for performance reasons: // dll_list::reserve_space(); diff --git a/winsup/cygwin/dll_init.h b/winsup/cygwin/dll_init.h index 369fc54..62739f7 100644 --- a/winsup/cygwin/dll_init.h +++ b/winsup/cygwin/dll_init.h @@ -59,9 +59,15 @@ struct dll DWORD image_size; void* preferred_base; PWCHAR modname; + FILE_BASIC_INFORMATION fbi; + FILE_INTERNAL_INFORMATION fii; + PWCHAR forkable_ntname; WCHAR ntname[1]; /* must be the last data member */ + void detach (); int init (); + void nominate_forkable (PCWCHAR); + bool create_forkable (); void run_dtors () { if (has_dtors) @@ -76,7 +82,32 @@ struct dll class dll_list { + /* forkables */ + enum + { + forkables_unknown, + forkables_impossible, + forkables_disabled, + forkables_needless, + forkables_needed, + forkables_created, + } + forkables_needs; + DWORD forkables_dirx_size; + PWCHAR forkables_dirx_ntname; + PWCHAR forkables_mutex_name; + HANDLE forkables_mutex; void track_self (); + size_t forkable_ntnamesize (dll_type, PCWCHAR fullntname, PCWCHAR modname); + void prepare_forkables_nomination (); + void update_forkables_needs (); + bool update_forkables (); + bool create_forkables (); + void denominate_forkables (); + bool close_mutex (); + void try_remove_forkables (PWCHAR dirbuf, size_t dirlen, size_t dirbufsize); + void set_forkables_inheritance (bool); + void request_forkables (); dll *end; dll *hold; @@ -85,6 +116,11 @@ class dll_list /* Use this buffer under loader lock conditions only. */ static WCHAR NO_COPY nt_max_path_buffer[NT_MAX_PATH]; public: + static HANDLE ntopenfile (PCWCHAR ntname, NTSTATUS *pstatus = NULL, + ULONG openopts = 0, ACCESS_MASK access = 0, + HANDLE rootDir = NULL); + static bool read_fii (HANDLE fh, PFILE_INTERNAL_INFORMATION pfii); + static bool read_fbi (HANDLE fh, PFILE_BASIC_INFORMATION pfbi); static PWCHAR form_ntname (PWCHAR ntbuf, size_t bufsize, PCWCHAR name); static PWCHAR form_shortname (PWCHAR shortbuf, size_t bufsize, PCWCHAR name); static PWCHAR nt_max_path_buf () @@ -115,6 +151,20 @@ public: void topsort_visit (dll* d, bool goto_tail); void append (dll* d); + void release_forkables (); + void cleanup_forkables (); + bool setup_forkables (bool with_forkables) + { + if (forkables_needs == forkables_impossible) + return true; /* short cut to not retry fork */ + /* Once used, always use forkables in current process chain. */ + if (forkables_needs != forkables_unknown) + with_forkables = true; + if (with_forkables) + request_forkables (); + return with_forkables; + } + dll *inext () { while ((hold = hold->next)) diff --git a/winsup/cygwin/fork.cc b/winsup/cygwin/fork.cc index 1cba33c..08ebf26 100644 --- a/winsup/cygwin/fork.cc +++ b/winsup/cygwin/fork.cc @@ -30,8 +30,13 @@ details. */ /* FIXME: Once things stabilize, bump up to a few minutes. */ #define FORK_WAIT_TIMEOUT (300 * 1000) /* 300 seconds */ +static int dofork (bool *with_forkables); class frok { + frok (bool *forkables) + : with_forkables (forkables) + {} + bool *with_forkables; bool load_dlls; child_info_fork ch; const char *errmsg; @@ -41,7 +46,7 @@ class frok int __stdcall parent (volatile char * volatile here); int __stdcall child (volatile char * volatile here); bool error (const char *fmt, ...); - friend int fork (); + friend int dofork (bool *with_forkables); }; static void @@ -308,6 +313,8 @@ frok::parent (volatile char * volatile stack_here) ch.refresh_cygheap (); ch.prefork (); /* set up process tracking pipes. */ + *with_forkables = dlls.setup_forkables (*with_forkables); + while (1) { PCWCHAR forking_progname = NULL; @@ -344,6 +351,7 @@ frok::parent (volatile char * volatile stack_here) { this_errno = geterrno_from_win_error (); error ("CreateProcessW failed for '%W'", myself->progname); + dlls.release_forkables (); memset (&pi, 0, sizeof (pi)); goto cleanup; } @@ -357,6 +365,8 @@ frok::parent (volatile char * volatile stack_here) CloseHandle (pi.hThread); hchild = pi.hProcess; + dlls.release_forkables (); + /* Protect the handle but name it similarly to the way it will be called in subproc handling. */ ProtectHandle1 (hchild, childhProc); @@ -523,7 +533,14 @@ cleanup: extern "C" int fork () { - frok grouped; + bool with_forkables = true; + return dofork (&with_forkables); +} + +static int +dofork (bool *with_forkables) +{ + frok grouped (with_forkables); debug_printf ("entering"); grouped.load_dlls = 0; diff --git a/winsup/cygwin/forkable.cc b/winsup/cygwin/forkable.cc new file mode 100644 index 0000000..cc28f9f --- /dev/null +++ b/winsup/cygwin/forkable.cc @@ -0,0 +1,1095 @@ +/* forkable.cc + + Copyright 2015 Red Hat, Inc. + +This software is a copyrighted work licensed under the terms of the +Cygwin license. Please consult the file "CYGWIN_LICENSE" for +details. */ + +#include "winsup.h" +#include "cygerrno.h" +#include "perprocess.h" +#include "sync.h" +#include "dll_init.h" +#include "environ.h" +#include "security.h" +#include "path.h" +#include "fhandler.h" +#include "dtable.h" +#include "cygheap.h" +#include "pinfo.h" +#include "shared_info.h" +#include "child_info.h" +#include "cygtls.h" +#include "exception.h" +#include <wchar.h> +#include <sys/reent.h> +#include <assert.h> +#include <tls_pbuf.h> + +/* Allow concurrent processes to use the same dll or exe + * via their hardlink while we delete our hardlink. */ +extern NTSTATUS unlink_nt_shareable (path_conv &pc); + +#define MUTEXSEP L"@" +#define PATHSEP L"\\" + +/* Create the lastsepcount directories found in ntdirname, where + counting is done along path separators (including trailing ones). + Returns true when these directories exist afterwards, false otherways. + The ntdirname is used for the path-splitting. */ +static bool +mkdirs (PWCHAR ntdirname, int lastsepcount) +{ + bool success = true; + int i = lastsepcount; + for (--i; i > 0; --i) + { + PWCHAR lastsep = wcsrchr (ntdirname, L'\\'); + if (!lastsep) + break; + *lastsep = L'\0'; + } + + for (++i; i <= lastsepcount; ++i) + { + if (success && (i == 0 || wcslen (wcsrchr (ntdirname, L'\\')) > 1)) + { + UNICODE_STRING dn; + RtlInitUnicodeString (&dn, ntdirname); + OBJECT_ATTRIBUTES oa; + InitializeObjectAttributes (&oa, &dn, 0, NULL, + sec_none_nih.lpSecurityDescriptor); + HANDLE dh = NULL; + NTSTATUS status; + IO_STATUS_BLOCK iosb; + status = NtCreateFile (&dh, GENERIC_READ | SYNCHRONIZE, + &oa, &iosb, NULL, FILE_ATTRIBUTE_NORMAL, + FILE_SHARE_READ | FILE_SHARE_WRITE, + FILE_CREATE, + FILE_DIRECTORY_FILE + | FILE_SYNCHRONOUS_IO_NONALERT, + NULL, 0); + if (NT_SUCCESS(status)) + NtClose (dh); + else if (status != STATUS_OBJECT_NAME_COLLISION) /* already exists */ + success = false; + debug_printf ("%y = NtCreateFile (%p, dir %W)", status, dh, ntdirname); + } + if (i < lastsepcount) + ntdirname[wcslen (ntdirname)] = L'\\'; /* restore original value */ + } + return success; +} + +/* Recursively remove the directory specified in ntmaxpathbuf, + using ntmaxpathbuf as the buffer to form subsequent filenames. */ +static void +rmdirs (WCHAR ntmaxpathbuf[NT_MAX_PATH]) +{ + PWCHAR basebuf = wcsrchr (ntmaxpathbuf, L'\\'); /* find last pathsep */ + if (basebuf && *(basebuf+1)) + basebuf += wcslen (basebuf); /* last pathsep is not trailing one */ + if (!basebuf) + basebuf = ntmaxpathbuf + wcslen (ntmaxpathbuf); + *basebuf = L'\0'; /* kill trailing pathsep, if any */ + + NTSTATUS status; + HANDLE hdir = dll_list::ntopenfile (ntmaxpathbuf, &status, + FILE_DIRECTORY_FILE | + FILE_DELETE_ON_CLOSE); + if (hdir == INVALID_HANDLE_VALUE) + return; + + *basebuf++ = L'\\'; /* (re-)add trailing pathsep */ + + struct { + FILE_DIRECTORY_INFORMATION fdi; + WCHAR buf[NAME_MAX]; + } fdibuf; + IO_STATUS_BLOCK iosb; + + while (NT_SUCCESS (status = NtQueryDirectoryFile (hdir, NULL, NULL, NULL, + &iosb, + &fdibuf, sizeof (fdibuf), + FileDirectoryInformation, + FALSE, NULL, FALSE))) + { + PFILE_DIRECTORY_INFORMATION pfdi = &fdibuf.fdi; + while (true) + { + int namelen = pfdi->FileNameLength / sizeof (WCHAR); + wcsncpy (basebuf, pfdi->FileName, namelen); + basebuf[namelen] = L'\0'; + + if (pfdi->FileAttributes & FILE_ATTRIBUTE_DIRECTORY) + { + if (wcscmp (basebuf, L".") && wcscmp (basebuf, L"..")) + rmdirs (ntmaxpathbuf); + } + else + { + UNICODE_STRING fn; + RtlInitUnicodeString (&fn, ntmaxpathbuf); + + path_conv pc (&fn); + unlink_nt_shareable (pc); /* move to bin */ + } + + if (!pfdi->NextEntryOffset) + break; + pfdi = (PFILE_DIRECTORY_INFORMATION)((caddr_t)pfdi + + pfdi->NextEntryOffset); + } + } + if (status != STATUS_NO_MORE_FILES) + debug_printf ("%y = NtQueryDirectoryFile (%p, io %y, info %d)", + status, hdir, iosb.Status, iosb.Information); + + CloseHandle (hdir); +} + +/* Get the NTFS file id for the real file behind the dll handle. + As we may open a wrong (or no) file while the dll is renamed, + we retry until we get the same file id a second time. + We use NtQueryVirtualMemory (MemorySectionName) for the current + file name, as GetModuleFileNameW () yields the as-loaded name. + While we have the file handle open, also read the attributes. + NOTE: Uses dll_list::nt_max_path_buf (). */ +static bool +stat_real_file_once (dll *d) +{ + if (d->fbi.FileAttributes != INVALID_FILE_ATTRIBUTES) + return true; + + tmp_pathbuf tp; + + HANDLE fhandle = INVALID_HANDLE_VALUE; + NTSTATUS status, fstatus; + PMEMORY_SECTION_NAME pmsi1; + MEMORY_SECTION_NAME msi2; + pmsi1 = (PMEMORY_SECTION_NAME) dll_list::nt_max_path_buf (); + RtlInitEmptyUnicodeString (&msi2.SectionFileName, tp.w_get (), 65535); + + /* Retry opening the real file name until that does not change any more. */ + status = NtQueryVirtualMemory (NtCurrentProcess (), d->handle, + MemorySectionName, pmsi1, 65536, NULL); + while (NT_SUCCESS (status) && + !RtlEqualUnicodeString (&msi2.SectionFileName, + &pmsi1->SectionFileName, FALSE)) + { + RtlCopyUnicodeString (&msi2.SectionFileName, &pmsi1->SectionFileName); + if (fhandle != INVALID_HANDLE_VALUE) + NtClose (fhandle); + pmsi1->SectionFileName.Buffer[pmsi1->SectionFileName.Length] = L'\0'; + fhandle = dll_list::ntopenfile (pmsi1->SectionFileName.Buffer, &fstatus); + status = NtQueryVirtualMemory (NtCurrentProcess (), d->handle, + MemorySectionName, pmsi1, 65536, NULL); + } + if (!NT_SUCCESS (status)) + system_printf ("WARNING: Unable (ntstatus %y) to query real file for %W", + status, d->ntname); + else if (fhandle == INVALID_HANDLE_VALUE) + system_printf ("WARNING: Unable (ntstatus %y) to open real file for %W", + fstatus, d->ntname); + if (fhandle == INVALID_HANDLE_VALUE) + return false; + + if (!dll_list::read_fii (fhandle, &d->fii) || + !dll_list::read_fbi (fhandle, &d->fbi)) + system_printf ("WARNING: Unable to read real file attributes for %W", + pmsi1->SectionFileName.Buffer); + + NtClose (fhandle); + return d->fbi.FileAttributes != INVALID_FILE_ATTRIBUTES; +} + +/* easy use of NtOpenFile */ +HANDLE +dll_list::ntopenfile (PCWCHAR ntname, NTSTATUS *pstatus, ULONG openopts, + ACCESS_MASK access, HANDLE rootDir) +{ + NTSTATUS status; + if (!pstatus) + pstatus = &status; + + UNICODE_STRING fn; + if (openopts & FILE_OPEN_BY_FILE_ID) + RtlInitCountedUnicodeString (&fn, ntname, 8); + else + RtlInitUnicodeString (&fn, ntname); + + OBJECT_ATTRIBUTES oa; + InitializeObjectAttributes (&oa, &fn, 0, rootDir, NULL); + + access |= FILE_READ_ATTRIBUTES; + if (openopts & FILE_DELETE_ON_CLOSE) + access |= DELETE; + if (openopts & FILE_DIRECTORY_FILE) + access |= FILE_LIST_DIRECTORY; + else + openopts |= FILE_NON_DIRECTORY_FILE; + + access |= SYNCHRONIZE; + openopts |= FILE_SYNCHRONOUS_IO_NONALERT; + + HANDLE fh = INVALID_HANDLE_VALUE; + ULONG share = FILE_SHARE_VALID_FLAGS; + IO_STATUS_BLOCK iosb; + *pstatus = NtOpenFile (&fh, access, &oa, &iosb, share, openopts); + if (openopts & FILE_OPEN_BY_FILE_ID) + debug_printf ("%y = NtOpenFile (%p, a %xh, sh %xh, o %xh, io %y, by id %llX)", + *pstatus, fh, access, share, openopts, iosb.Status, *(LONGLONG*)fn.Buffer); + else + debug_printf ("%y = NtOpenFile (%p, a %xh, sh %xh, o %xh, io %y, '%W')", + *pstatus, fh, access, share, openopts, iosb.Status, fn.Buffer); + + return NT_SUCCESS(*pstatus) ? fh : INVALID_HANDLE_VALUE; +} + +bool +dll_list::read_fii (HANDLE fh, PFILE_INTERNAL_INFORMATION pfii) +{ + pfii->IndexNumber.QuadPart = -1LL; + + NTSTATUS status; + IO_STATUS_BLOCK iosb; + status = NtQueryInformationFile (fh, &iosb, + pfii, sizeof (*pfii), + FileInternalInformation); + if (!NT_SUCCESS (status)) + { + system_printf ("WARNING: %y = NtQueryInformationFile (%p," + " InternalInfo, io.Status %y)", + status, fh, iosb.Status); + pfii->IndexNumber.QuadPart = -1LL; + return false; + } + return true; +} + +bool +dll_list::read_fbi (HANDLE fh, PFILE_BASIC_INFORMATION pfbi) +{ + pfbi->FileAttributes = INVALID_FILE_ATTRIBUTES; + pfbi->LastWriteTime.QuadPart = -1LL; + + NTSTATUS status; + IO_STATUS_BLOCK iosb; + status = NtQueryInformationFile (fh, &iosb, + pfbi, sizeof (*pfbi), + FileBasicInformation); + if (!NT_SUCCESS (status)) + { + system_printf ("WARNING: %y = NtQueryInformationFile (%p," + " BasicInfo, io.Status %y)", + status, fh, iosb.Status); + pfbi->FileAttributes = INVALID_FILE_ATTRIBUTES; + pfbi->LastWriteTime.QuadPart = -1LL; + return false; + } + return true; +} + +/* Into buf if not NULL, write the IndexNumber in pli. + Return the number of characters (that would be) written. */ +static int +format_IndexNumber (PWCHAR buf, ssize_t bufsize, LARGE_INTEGER const *pli) +{ + if (!buf) + return 16; + if (bufsize >= 0 && bufsize <= 16) + return 0; + return __small_swprintf (buf, L"%016X", pli->QuadPart); +} + +/* Into buf if not NULL, write the ntname of cygwin installation_root. + Return the number of characters (that would be) written. */ +static int +rootname (PWCHAR buf, ssize_t bufsize) +{ + UNICODE_STRING &cygroot = cygheap->installation_root; + if (!buf) + return 6 /* "\??\UN" */ + cygroot.Length / sizeof (WCHAR); + return dll_list::form_ntname (buf, bufsize, cygroot.Buffer) - buf; +} + +/* Into buf if not NULL, write the string representation of current user sid. + Return the number of characters (that would be) written. */ +static int +sidname (PWCHAR buf, ssize_t bufsize) +{ + if (!buf) + return 128; + if (bufsize >= 0 && bufsize <= 128) + return 0; + UNICODE_STRING sid; + WCHAR sidbuf[128+1]; + RtlInitEmptyUnicodeString (&sid, sidbuf, sizeof (sidbuf)); + RtlConvertSidToUnicodeString (&sid, cygheap->user.sid (), FALSE); + return wcpcpy (buf, sid.Buffer) - buf; +} + +/* Into buf if not NULL, write the IndexNumber of the main executable. + Return the number of characters (that would be) written. */ +static int +exename (PWCHAR buf, ssize_t bufsize) +{ + if (!buf) + return format_IndexNumber (NULL, bufsize, NULL); + dll *d = dlls.main_executable; + return format_IndexNumber (buf, bufsize, &d->fii.IndexNumber); +} + +/* Into buf if not NULL, write the newest dll's LastWriteTime. + Return the number of characters (that would be) written. */ +static int +lwtimename (PWCHAR buf, ssize_t bufsize) +{ + if (!buf) + return sizeof (LARGE_INTEGER) * 2; + if (bufsize >= 0 && bufsize <= (int)sizeof (LARGE_INTEGER) * 2) + return 0; + + LARGE_INTEGER newest = { 0 }; + /* Need by-handle-file-information for _all_ loaded dlls, + as most recent ctime forms the hardlinks directory. */ + dll *d = &dlls.start; + while ((d = d->next)) + { + /* LastWriteTime more properly tells the last file-content modification + time, because a newly created hardlink may have a different + CreationTime compared to the original file. */ + if (d->fbi.LastWriteTime.QuadPart > newest.QuadPart) + newest = d->fbi.LastWriteTime; + } + + return __small_swprintf (buf, L"%016X", newest); +} + +struct namepart { + PCWCHAR text; /* used when no pathfunc, description otherwise */ + int (*textfunc)(PWCHAR buf, ssize_t bufsize); + bool mutex_from_dir; /* on path-separators add mutex-separator */ + bool create_dir; +}; +/* mutex name is formed along dir names */ +static namepart NO_COPY_RO const +forkable_nameparts[] = { + /* text textfunc mutex_from_dir create */ + { L"<cygroot>", rootname, false, false, }, + { L"\\var\\run\\", NULL, false, false, }, + { L"cygfork", NULL, true, false, }, + { L"<sid>", sidname, true, true, }, + { L"<exe>", exename, false, false, }, + { MUTEXSEP, NULL, false, false, }, + { L"<ctime>", lwtimename, true, true, }, + + { NULL, NULL }, +}; + +/* Nominate the hardlink to an individual DLL inside dirx_name, + that ends with the path separator (hence the "x" varname). + With NULL as dirx_name, never nominate the hardlink any more. + With "" as dirx_name, denominate the hardlink. */ +void +dll::nominate_forkable (PCWCHAR dirx_name) +{ + if (!dirx_name) + { + debug_printf ("type %d disable %W", type, ntname); + forkable_ntname = NULL; /* never create a hardlink for this dll */ + } + + if (!forkable_ntname) + return; + + PWCHAR next = wcpcpy (forkable_ntname, dirx_name); + + if (!*forkable_ntname) + return; /* denominate */ + + if (type < DLL_LOAD) + wcpcpy (next, modname); + else + { + /* Avoid lots of extra directories for loaded dll's: + * mangle full path into one single directory name, + * just keep original filename intact. The original + * filename is necessary to serve as linked + * dependencies of dynamically loaded dlls. */ + PWCHAR lastpathsep = wcsrchr (ntname, L'\\'); + if (!lastpathsep) + { + forkable_ntname = NULL; + return; + } + *lastpathsep = L'\0'; + HANDLE fh = dll_list::ntopenfile (ntname, NULL, FILE_DIRECTORY_FILE); + *lastpathsep = L'\\'; + + FILE_INTERNAL_INFORMATION fii = { 0 }; + if (fh != INVALID_HANDLE_VALUE) + { + dll_list::read_fii (fh, &fii); + NtClose (fh); + } + next += format_IndexNumber (next, -1, &fii.IndexNumber); + wcpcpy (next, lastpathsep); + } +} + +/* Create the nominated hardlink for one indivitual dll, + inside another subdirectory when dynamically loaded. */ +bool +dll::create_forkable () +{ + if (!forkable_ntname || !*forkable_ntname) + return true; /* disabled */ + + PWCHAR ntname = forkable_ntname; + + PWCHAR last = NULL; + bool success = true; + if (type >= DLL_LOAD) + { + last = wcsrchr (ntname, L'\\'); + if (!last) + return false; + *last = L'\0'; + success = mkdirs (ntname, 1); + *last = L'\\'; + if (!success) + return false; + } + + /* open device as parent handle for FILE_OPEN_BY_FILE_ID */ + PWCHAR devname = dll_list::nt_max_path_buf (); + PWCHAR n = ntname; + PWCHAR d = devname; + int pathseps = 0; + while (*n) + { + if (*d == L'\\' && ++pathseps > 4) + break; // "\\??\\UNC\\server\\share" + *d = *n++; + if (*d++ == L':') + break; // "\\??\\C:" + } + *d = L'\0'; + + HANDLE devhandle = dll_list::ntopenfile (devname); + if (devhandle == INVALID_HANDLE_VALUE) + return false; /* impossible */ + + HANDLE fh = dll_list::ntopenfile ((PCWCHAR)&fii.IndexNumber, NULL, + FILE_OPEN_BY_FILE_ID, + FILE_WRITE_ATTRIBUTES, + devhandle); + NtClose (devhandle); + if (fh == INVALID_HANDLE_VALUE) + return false; /* impossible */ + + int ntlen = wcslen (ntname); + int bufsize = sizeof (FILE_LINK_INFORMATION) + ntlen * sizeof (*ntname); + PFILE_LINK_INFORMATION pfli = (PFILE_LINK_INFORMATION) alloca (bufsize); + + wcscpy (pfli->FileName, ntname); + + pfli->FileNameLength = ntlen * sizeof (*ntname); + pfli->ReplaceIfExists = FALSE; /* allow concurrency */ + pfli->RootDirectory = NULL; + + IO_STATUS_BLOCK iosb; + NTSTATUS status = NtSetInformationFile (fh, &iosb, pfli, bufsize, + FileLinkInformation); + NtClose (fh); + debug_printf ("%y = NtSetInformationFile (%p, FileLink %W, iosb.Status %y)", + status, fh, pfli->FileName, iosb.Status); + if (NT_SUCCESS (status) || status == STATUS_OBJECT_NAME_COLLISION) + /* We've not found a performant way yet to protect fork against updates + to main executables and/or dlls that do not reside on the same NTFS + filesystem as the <cygroot>/var/run/cygfork/ directory. + But as long as the main executable can be hardlinked, dll redirection + works for any other hardlink-able dll, while non-hardlink-able dlls + are used from their original location. */ + return true; + + return false; +} + +/* return the number of characters necessary to store one forkable name */ +size_t +dll_list::forkable_ntnamesize (dll_type type, PCWCHAR fullntname, PCWCHAR modname) +{ + if (forkables_needs == forkables_impossible) + return 0; + + if (!forkables_dirx_size) + { + DWORD forkables_mutex_size = 0; + bool needsep = false; + for (namepart const *part = forkable_nameparts; part->text; ++part) + { + if (needsep) + { + forkables_dirx_size += wcslen (PATHSEP); + forkables_mutex_size += wcslen (MUTEXSEP); + } + needsep = part->mutex_from_dir; + int len = 0; + if (part->textfunc) + len = part->textfunc (NULL, 0); + else + len = wcslen (part->text); + forkables_dirx_size += len; + forkables_mutex_size += len; + } + /* trailing path sep */ + forkables_dirx_size += wcslen (PATHSEP); + /* trailing zeros */ + ++forkables_dirx_size; + ++forkables_mutex_size; + + /* allocate here, to avoid cygheap size changes during fork */ + forkables_dirx_ntname = (PWCHAR) cmalloc (HEAP_2_DLL, + (forkables_dirx_size + forkables_mutex_size) * + sizeof (*forkables_dirx_ntname)); + *forkables_dirx_ntname = L'\0'; + + forkables_mutex_name = forkables_dirx_ntname + forkables_dirx_size; + *forkables_mutex_name = L'\0'; + } + + size_t ret = forkables_dirx_size; + if (type >= DLL_LOAD) + ret += format_IndexNumber (NULL, -1, NULL) + 1; /* one more directory */ + return ret + wcslen (modname); +} + +/* Prepare top-level names necessary to nominate individual DLL hardlinks, + eventually releasing/removing previous forkable hardlinks. */ +void +dll_list::prepare_forkables_nomination () +{ + if (!forkables_dirx_ntname) + return; + + dll *d = &dlls.start; + while ((d = d->next)) + stat_real_file_once (d); /* uses nt_max_path_buf () */ + + PWCHAR pbuf = nt_max_path_buf (); + + bool needsep = false; + bool domutex = false; + namepart const *part; + for (part = forkable_nameparts; part->text; ++part) + { + if (part->mutex_from_dir) + domutex = true; /* mutex naming starts with first mutex_from_dir */ + if (!domutex) + continue; + if (needsep) + pbuf += __small_swprintf (pbuf, L"%W", MUTEXSEP); + needsep = part->mutex_from_dir; + if (part->textfunc) + pbuf += part->textfunc (pbuf, -1); + else + pbuf += __small_swprintf (pbuf, L"%W", part->text); + } + + if (!wcscmp (forkables_mutex_name, nt_max_path_buf ())) + return; /* nothing changed */ + + if (*forkables_mutex_name && + wcscmp (forkables_mutex_name, nt_max_path_buf ())) + { + /* The mutex name has changed since last fork and we either have + dlopen'ed a more recent or dlclose'd the most recent dll, + so we will not use the current forkable hardlinks any more. + Removing from the file system is done later, upon exit. */ + close_mutex (); + denominate_forkables (); + } + wcscpy (forkables_mutex_name, nt_max_path_buf ()); + + pbuf = forkables_dirx_ntname; + needsep = false; + for (namepart const *part = forkable_nameparts; part->text; ++part) + { + if (needsep) + pbuf += __small_swprintf (pbuf, L"%W", PATHSEP); + needsep = part->mutex_from_dir; + if (part->textfunc) + pbuf += part->textfunc (pbuf, -1); + else + pbuf += __small_swprintf (pbuf, L"%W", part->text); + } + pbuf += __small_swprintf (pbuf, L"%W", PATHSEP); + + debug_printf ("forkables dir %W", forkables_dirx_ntname); + debug_printf ("forkables mutex %W", forkables_mutex_name); +} + +/* Test if creating hardlinks is necessary. If creating hardlinks is possible + in general, each individual dll is tested if its previously created + hardlink (if any, or the original file) still is the same. + Testing is protected against hardlink removal by concurrent processes. */ +void +dll_list::update_forkables_needs () +{ + dll *d; + + if (forkables_needs == forkables_unknown) + { + /* check if filesystem of forkables dir is NTFS */ + PWCHAR pbuf = nt_max_path_buf (); + for (namepart const *part = forkable_nameparts; part->text; ++part) + { + if (part->mutex_from_dir) + break; /* leading non-mutex-naming dirs, must exist anyway */ + if (part->textfunc) + pbuf += part->textfunc (pbuf, -1); + else + pbuf += __small_swprintf (pbuf, L"%W", part->text); + } + + UNICODE_STRING fn; + RtlInitUnicodeString (&fn, nt_max_path_buf ()); + + fs_info fsi; + if (fsi.update (&fn, NULL) && +/* FIXME: !fsi.is_readonly () && */ + fsi.is_ntfs ()) + forkables_needs = forkables_disabled; /* check directory itself */ + else + { + debug_printf ("impossible, not on NTFS %W", fn.Buffer); + forkables_needs = forkables_impossible; + } + } + + if (forkables_needs == forkables_impossible) + return; /* we have not created any hardlink, nothing to clean up */ + + if (forkables_needs == forkables_disabled || + forkables_needs == forkables_needless || + forkables_needs == forkables_created) + { + /* (re-)check existence of forkables dir */ + PWCHAR pbuf = nt_max_path_buf (); + for (namepart const *part = forkable_nameparts; part->text; ++part) + { + if (part->textfunc) + pbuf += part->textfunc (pbuf, -1); + else + pbuf += __small_swprintf (pbuf, L"%W", part->text); + if (part->mutex_from_dir) + break; /* up to first mutex-naming dir */ + } + pbuf = nt_max_path_buf (); + + HANDLE dh = ntopenfile (pbuf, NULL, FILE_DIRECTORY_FILE); + if (dh != INVALID_HANDLE_VALUE) + { + NtClose (dh); + if (forkables_needs == forkables_disabled) + forkables_needs = forkables_needless; + } + else if (forkables_needs != forkables_disabled) + { + debug_printf ("disabled, disappearing %W", pbuf); + close_mutex (); + denominate_forkables (); + forkables_needs = forkables_disabled; + } + else + debug_printf ("disabled, missing %W", pbuf); + } + + if (forkables_needs == forkables_disabled) + return; + + if (forkables_needs == forkables_created) + { + /* already have created hardlinks in this process, ... */ + forkables_needs = forkables_needless; + d = &start; + while ((d = d->next) != NULL) + if (d->forkable_ntname && !*d->forkable_ntname) + { + /* ... but another dll was loaded since last fork */ + debug_printf ("needed, since last fork loaded %W", d->ntname); + forkables_needs = forkables_needed; + break; + } + } + + if (forkables_needs > forkables_needless) + return; /* no need to check anything else */ + + if (forkables_needs != forkables_needless) + { + /* paranoia */ + system_printf ("WARNING: invalid forkables_needs value %d", + forkables_needs); + return; + } + + forkables_needs = forkables_needed; +} + +/* Create the nominated forkable hardlinks and directories as necessary, + mutex-protected to avoid concurrent processes removing them. */ +bool +dll_list::update_forkables () +{ + /* existence of mutex indicates that we use these hardlinks */ + if (!forkables_mutex) + { + /* neither my parent nor myself did have need for hardlinks yet */ + forkables_mutex = CreateMutexW (&sec_none, FALSE, + forkables_mutex_name); + debug_printf ("%p = CreateMutexW (%W): %E", + forkables_mutex, forkables_mutex_name); + if (!forkables_mutex) + return false; + + /* Make sure another process does not rmdirs_synchronized () */ + debug_printf ("WFSO (%p, %W, inf)...", + forkables_mutex, forkables_mutex_name); + DWORD ret = WaitForSingleObject (forkables_mutex, INFINITE); + debug_printf ("%u = WFSO (%p, %W)", + ret, forkables_mutex, forkables_mutex_name); + switch (ret) + { + case WAIT_OBJECT_0: + case WAIT_ABANDONED: + break; + default: + system_printf ("cannot wait for mutex %W: %E", + forkables_mutex_name); + return false; + } + + BOOL bret = ReleaseMutex (forkables_mutex); + debug_printf ("%d = ReleaseMutex (%p, %W)", + bret, forkables_mutex, forkables_mutex_name); + } + + return create_forkables (); +} + +/* Create the nominated forkable hardlinks and directories as necessary, + as well as the .local file for dll-redirection. */ +bool +dll_list::create_forkables () +{ + bool success = true; + + int lastsepcount = 1; /* we have trailing pathsep */ + for (namepart const *part = forkable_nameparts; part->text; ++part) + if (part->create_dir) + ++lastsepcount; + + PWCHAR ntname = nt_max_path_buf (); + wcsncpy (ntname, forkables_dirx_ntname, NT_MAX_PATH); + + if (!mkdirs (ntname, lastsepcount)) + success = false; + + if (success) + { + /* create the DotLocal file as empty file */ + wcsncat (ntname, main_executable->modname, NT_MAX_PATH); + wcsncat (ntname, L".local", NT_MAX_PATH); + + UNICODE_STRING fn; + RtlInitUnicodeString (&fn, ntname); + + OBJECT_ATTRIBUTES oa; + InitializeObjectAttributes (&oa, &fn, 0, NULL, + sec_none_nih.lpSecurityDescriptor); + HANDLE hlocal = NULL; + NTSTATUS status; + IO_STATUS_BLOCK iosb; + status = NtCreateFile (&hlocal, GENERIC_WRITE | SYNCHRONIZE, + &oa, &iosb, NULL, FILE_ATTRIBUTE_NORMAL, + FILE_SHARE_READ | FILE_SHARE_WRITE, + FILE_CREATE, + FILE_NON_DIRECTORY_FILE + | FILE_SYNCHRONOUS_IO_NONALERT, + NULL, 0); + if (NT_SUCCESS (status)) + CloseHandle (hlocal); + else if (status != STATUS_OBJECT_NAME_COLLISION) /* already exists */ + success = false; + debug_printf ("%y = NtCreateFile (%p, %W)", status, hlocal, ntname); + } + + if (success) + { + dll *d = &start; + while ((d = d->next)) + if (!d->create_forkable ()) + d->nominate_forkable (NULL); /* never again */ + debug_printf ("hardlinks created"); + } + + return success; +} + +static void +rmdirs_synchronized (WCHAR ntbuf[NT_MAX_PATH], int depth, int maxdepth, + PFILE_DIRECTORY_INFORMATION pfdi, ULONG fdisize) +{ + if (depth == maxdepth) + { + debug_printf ("sync on %W", ntbuf); + /* calculate mutex name from path parts, using + full path name length to allocate mutex name buffer */ + WCHAR mutexname[wcslen (ntbuf)]; + mutexname[0] = L'\0'; + PWCHAR mutexnext = mutexname; + + /* mutex name is formed by dir names */ + int pathcount = 0; + for (namepart const *part = forkable_nameparts; part->text; ++part) + if (part->mutex_from_dir) + ++pathcount; + + PWCHAR pathseps[pathcount]; + + /* along the path separators split needed path parts */ + int i = pathcount; + while (--i >= 0) + if ((pathseps[i] = wcsrchr (ntbuf, L'\\'))) + *pathseps[i] = L'\0'; + else + return; /* something's wrong */ + + /* build the mutex name from dir names */ + for (i = 0; i < pathcount; ++i) + { + if (i > 0) + mutexnext = wcpcpy (mutexnext, MUTEXSEP); + mutexnext = wcpcpy (mutexnext, &pathseps[i][1]); + *pathseps[i] = L'\\'; /* restore full path */ + } + + HANDLE mutex = CreateMutexW (&sec_none_nih, TRUE, mutexname); + DWORD lasterror = GetLastError (); + debug_printf ("%p = CreateMutexW (%W): %E", mutex, mutexname); + if (mutex) + { + if (lasterror != ERROR_ALREADY_EXISTS) + { + debug_printf ("cleaning up for mutex %W", mutexname); + rmdirs (ntbuf); + } + BOOL bret = CloseHandle (mutex); + debug_printf ("%d = CloseHandle (%p, %W): %E", + bret, mutex, mutexname); + } + return; + } + + IO_STATUS_BLOCK iosb; + NTSTATUS status; + + HANDLE hdir = dll_list::ntopenfile (ntbuf, &status, + FILE_DIRECTORY_FILE | + (depth ? FILE_DELETE_ON_CLOSE : 0)); + if (hdir == INVALID_HANDLE_VALUE) + return; + + PWCHAR plast = ntbuf + wcslen (ntbuf); + while (NT_SUCCESS (status = NtQueryDirectoryFile (hdir, + NULL, NULL, NULL, &iosb, + pfdi, fdisize, + FileDirectoryInformation, + TRUE, NULL, FALSE))) + if (pfdi->FileAttributes & FILE_ATTRIBUTE_DIRECTORY) + { + int namelen = pfdi->FileNameLength / sizeof (WCHAR); + if (!wcsncmp (pfdi->FileName, L".", namelen) || + !wcsncmp (pfdi->FileName, L"..", namelen)) + continue; + *plast = L'\\'; + wcsncpy (plast+1, pfdi->FileName, namelen); + plast[1+namelen] = L'\0'; + rmdirs_synchronized (ntbuf, depth+1, maxdepth, pfdi, fdisize); + *plast = L'\0'; + } + if (status != STATUS_NO_MORE_FILES) + debug_printf ("%y = NtQueryDirectoryFile (%p, io %y, info %d)", + status, hdir, iosb.Status, iosb.Information); + CloseHandle (hdir); +} + +/* Try to lock the mutex handle with almost no timeout, then close the + mutex handle. Locking before closing is to get the mutex closing + promoted synchronously, otherways we might end up with no one + succeeding in create-with-lock, which is the precondition + to actually remove the hardlinks from the filesystem. */ +bool +dll_list::close_mutex () +{ + if (!forkables_mutex || !*forkables_mutex_name) + return false; + + HANDLE hmutex = forkables_mutex; + forkables_mutex = NULL; + + bool locked = false; + DWORD ret = WaitForSingleObject (hmutex, 1); + debug_printf ("%u = WFSO (%p, %W, 1)", + ret, hmutex, forkables_mutex_name); + switch (ret) + { + case WAIT_OBJECT_0: + case WAIT_ABANDONED: + locked = true; + break; + case WAIT_TIMEOUT: + break; + default: + system_printf ("error locking mutex %W: %E", forkables_mutex_name); + break; + } + BOOL bret = CloseHandle (hmutex); + debug_printf ("%d = CloseHandle (%p, %W): %E", + bret, hmutex, forkables_mutex_name); + return locked; +} + +/* Release the forkable hardlinks, and remove them if the + mutex can be create-locked after locked-closing. */ +void +dll_list::cleanup_forkables () +{ + if (!forkables_dirx_ntname) + return; + + bool locked = close_mutex (); + + /* Start the removal below with current forkables dir, + which is cleaned in denominate_forkables (). */ + PWCHAR buf = nt_max_path_buf (); + PWCHAR pathsep = wcpncpy (buf, forkables_dirx_ntname, NT_MAX_PATH); + buf[NT_MAX_PATH-1] = L'\0'; + + denominate_forkables (); + + if (!locked) + return; + + /* drop last path separator */ + while (--pathsep >= buf && *pathsep != L'\\'); + *pathsep = L'\0'; + + try_remove_forkables (buf, pathsep - buf, NT_MAX_PATH); +} + +void +dll_list::try_remove_forkables (PWCHAR dirbuf, size_t dirlen, size_t dirbufsize) +{ + /* Instead of just the current forkables, try to remove any forkables + found, to ensure some cleanup even in situations like power-loss. */ + PWCHAR end = dirbuf + wcslen (dirbuf); + int backcount = 0; + for (namepart const *part = forkable_nameparts; part->text; ++part) + if (part->create_dir) + { + /* drop one path separator per create_dir */ + while (--end >= dirbuf && *end != L'\\'); + if (end < dirbuf) + return; + *end = L'\0'; + ++backcount; + } + + /* reading one at a time to reduce stack pressure */ + struct { + FILE_DIRECTORY_INFORMATION fdi; + WCHAR buf[NAME_MAX]; + } fdibuf; + rmdirs_synchronized (dirbuf, 0, backcount, &fdibuf.fdi, sizeof (fdibuf)); +} + +void +dll_list::denominate_forkables () +{ + *forkables_dirx_ntname = L'\0'; + *forkables_mutex_name = L'\0'; + + dll *d = &start; + while ((d = d->next)) + d->nominate_forkable (forkables_dirx_ntname); +} + +/* Set or clear HANDLE_FLAG_INHERIT for all handles necessary + to maintain forkables-hardlinks. */ +void +dll_list::set_forkables_inheritance (bool inherit) +{ + DWORD mask = HANDLE_FLAG_INHERIT; + DWORD flags = inherit ? HANDLE_FLAG_INHERIT : 0; + + if (forkables_mutex) + SetHandleInformation (forkables_mutex, mask, flags); +} + +/* create the forkable hardlinks, if necessary */ +void +dll_list::request_forkables () +{ + if (!forkables_dirx_ntname) + return; + + /* Even on forkables_impossible, keep the number of open handles + stable across the fork, and close them when releasing only. */ + prepare_forkables_nomination (); + + update_forkables_needs (); + + set_forkables_inheritance (true); + + if (forkables_needs <= forkables_needless) + return; + + dll *d = &start; + while ((d = d->next)) + d->nominate_forkable (forkables_dirx_ntname); + + bool updated = update_forkables (); + + if (!updated) + forkables_needs = forkables_needless; + else + forkables_needs = forkables_created; +} + + +void +dll_list::release_forkables () +{ + if (!forkables_dirx_ntname) + return; + + set_forkables_inheritance (false); + + if (forkables_needs == forkables_impossible) + { + cleanup_forkables (); + + dll *d = &start; + while ((d = d->next)) + d->forkable_ntname = NULL; + + cfree (forkables_dirx_ntname); + forkables_dirx_ntname = NULL; + forkables_mutex_name = NULL; + } +} diff --git a/winsup/cygwin/pinfo.cc b/winsup/cygwin/pinfo.cc index b2bfb2b..445bd35 100644 --- a/winsup/cygwin/pinfo.cc +++ b/winsup/cygwin/pinfo.cc @@ -25,6 +25,7 @@ details. */ #include "cygtls.h" #include "tls_pbuf.h" #include "child_info.h" +#include "dll_init.h" class pinfo_basic: public _pinfo { @@ -216,6 +217,8 @@ pinfo::exit (DWORD n) int exitcode = self->exitcode & 0xffff; if (!self->cygstarted) exitcode = ((exitcode & 0xff) << 8) | ((exitcode >> 8) & 0xff); + sigproc_printf ("Calling dlls.cleanup_forkables n %y, exitcode %y", n, exitcode); + dlls.cleanup_forkables (); sigproc_printf ("Calling ExitProcess n %y, exitcode %y", n, exitcode); if (!TerminateProcess (GetCurrentProcess (), exitcode)) system_printf ("TerminateProcess failed, %E"); diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc index 8a995e8..b776174 100644 --- a/winsup/cygwin/syscalls.cc +++ b/winsup/cygwin/syscalls.cc @@ -670,8 +670,8 @@ check_dir_not_empty (HANDLE dir, path_conv &pc) return STATUS_SUCCESS; } -NTSTATUS -unlink_nt (path_conv &pc) +static NTSTATUS +_unlink_nt (path_conv &pc, bool shareable) { NTSTATUS status; HANDLE fh, fh_ro = NULL; @@ -793,6 +793,9 @@ retry_open: bin so that it actually disappears from its directory even though its in use. Otherwise, if opening doesn't fail, the file is not in use and we can go straight to setting the delete disposition flag. + However, while we have the file open with FILE_SHARE_DELETE, using + this file via another hardlink for anything other than DELETE by + concurrent processes fails. The 'shareable' argument is to prevent this. NOTE: The missing sharing modes FILE_SHARE_READ and FILE_SHARE_WRITE do NOT result in a STATUS_SHARING_VIOLATION, if another handle is @@ -802,7 +805,10 @@ retry_open: will succeed. So, apparently there is no reliable way to find out if a file is already open elsewhere for other purposes than reading and writing data. */ - status = NtOpenFile (&fh, access, &attr, &io, FILE_SHARE_DELETE, flags); + if (shareable) + status = STATUS_SHARING_VIOLATION; + else + status = NtOpenFile (&fh, access, &attr, &io, FILE_SHARE_DELETE, flags); /* STATUS_SHARING_VIOLATION is what we expect. STATUS_LOCK_NOT_GRANTED can be generated under not quite clear circumstances when trying to open a file on NFS with FILE_SHARE_DELETE only. This has been observed with @@ -1052,6 +1058,18 @@ out: return status; } +NTSTATUS +unlink_nt (path_conv &pc) +{ + return _unlink_nt (pc, false); +} + +NTSTATUS +unlink_nt_shareable (path_conv &pc) +{ + return _unlink_nt (pc, true); +} + extern "C" int unlink (const char *ourname) { |