From 2267b87f738710dfdb3b8bba27906b827e7c2516 Mon Sep 17 00:00:00 2001 From: corinna Date: Wed, 17 Jan 2007 10:49:23 +0000 Subject: [PATCH] * mmap.cc (MapView9x): Note possible uselessness of retrying. (MapViewNT): Ditto. (mmap64): Fix pre-reservation to work for non NULL, non MAP_FIXED. --- winsup/cygwin/ChangeLog | 6 ++++++ winsup/cygwin/mmap.cc | 31 +++++++++++++++++++++++-------- 2 files changed, 29 insertions(+), 8 deletions(-) diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog index 786ba4cb01..beafd1b90c 100644 --- a/winsup/cygwin/ChangeLog +++ b/winsup/cygwin/ChangeLog @@ -1,3 +1,9 @@ +2007-01-17 Corinna Vinschen + + * mmap.cc (MapView9x): Note possible uselessness of retrying. + (MapViewNT): Ditto. + (mmap64): Fix pre-reservation to work for non NULL, non MAP_FIXED. + 2007-01-16 Corinna Vinschen * autoload.cc (RtlAnsiStringToUnicodeString): Define. diff --git a/winsup/cygwin/mmap.cc b/winsup/cygwin/mmap.cc index 76524e0207..4273957a65 100644 --- a/winsup/cygwin/mmap.cc +++ b/winsup/cygwin/mmap.cc @@ -328,7 +328,10 @@ MapView9x (HANDLE h, void *addr, size_t len, DWORD openflags, /* Try mapping using the given address first, even if it's NULL. If it failed, and addr was not NULL and flags is not MAP_FIXED, - try again with NULL address. */ + try again with NULL address. + + Note: Retrying the mapping might be unnecessary, now that mmap64 checks + for a valid memory area first. */ if (!addr) base = MapViewOfFile (h, access, high, low, len); else @@ -357,7 +360,10 @@ MapViewNT (HANDLE h, void *addr, size_t len, DWORD openflags, /* Try mapping using the given address first, even if it's NULL. If it failed, and addr was not NULL and flags is not MAP_FIXED, - try again with NULL address. */ + try again with NULL address. + + Note: Retrying the mapping might be unnecessary, now that mmap64 checks + for a valid memory area first. */ ret = NtMapViewOfSection (h, GetCurrentProcess (), &base, 0, commitsize, &offset, &viewsize, ViewShare, alloc_type, protect); if (!NT_SUCCESS (ret) && addr && !fixed (flags)) @@ -1225,18 +1231,27 @@ go_ahead: subsequent real mappings. This ensures that we have enough space for the whole thing. */ orig_len = roundup2 (orig_len, pagesize); - addr = VirtualAlloc (addr, orig_len, MEM_TOP_DOWN | MEM_RESERVE, - PAGE_READWRITE); - if (!addr) + PVOID newaddr = VirtualAlloc (addr, orig_len, MEM_TOP_DOWN | MEM_RESERVE, + PAGE_READWRITE); + if (!newaddr) { - __seterrno (); - goto out; + /* If addr is not NULL, but MAP_FIXED isn't given, allow the OS + to choose. */ + if (addr && !fixed (flags)) + newaddr = VirtualAlloc (NULL, orig_len, MEM_TOP_DOWN | MEM_RESERVE, + PAGE_READWRITE); + if (!newaddr) + { + __seterrno (); + goto out; + } } - if (!VirtualFree (addr, 0, MEM_RELEASE)) + if (!VirtualFree (newaddr, 0, MEM_RELEASE)) { __seterrno (); goto out; } + addr = newaddr; } base = mmap_worker (fh, (caddr_t) addr, len, prot, flags, fd, off); -- 2.11.0