diff options
Diffstat (limited to 'winsup/cygwin/mmap.cc')
| -rw-r--r-- | winsup/cygwin/mmap.cc | 110 |
1 files changed, 93 insertions, 17 deletions
diff --git a/winsup/cygwin/mmap.cc b/winsup/cygwin/mmap.cc index cb8b8284e..984504ede 100644 --- a/winsup/cygwin/mmap.cc +++ b/winsup/cygwin/mmap.cc @@ -1531,35 +1531,111 @@ munlock (const void *addr, size_t len) return ret; } +/* This is required until Mingw-w64 catches up with newer functions. */ +extern "C" WINAPI DWORD DiscardVirtualMemory (PVOID, SIZE_T); + extern "C" int posix_madvise (void *addr, size_t len, int advice) { - int ret; + int ret = 0; /* Check parameters. */ if (advice < POSIX_MADV_NORMAL || advice > POSIX_MADV_DONTNEED || !len) - ret = EINVAL; - else { - /* Check requested memory area. */ - MEMORY_BASIC_INFORMATION m; - char *p = (char *) addr; - char *endp = p + len; - while (p < endp) + ret = EINVAL; + goto out; + } + + /* Check requested memory area. */ + MEMORY_BASIC_INFORMATION m; + char *p, *endp; + + for (p = (char *) addr, endp = p + len; + p < endp; + p = (char *) m.BaseAddress + m.RegionSize) + { + if (!VirtualQuery (p, &m, sizeof m) || m.State == MEM_FREE) { - if (!VirtualQuery (p, &m, sizeof m) || m.State == MEM_FREE) + ret = ENOMEM; + break; + } + } + if (ret) + goto out; + switch (advice) + { + case POSIX_MADV_WILLNEED: + { + /* Align address and length values to page size. */ + size_t pagesize = wincap.allocation_granularity (); + PVOID base = (PVOID) rounddown ((uintptr_t) addr, pagesize); + SIZE_T size = roundup2 (((uintptr_t) addr - (uintptr_t) base) + + len, pagesize); + WIN32_MEMORY_RANGE_ENTRY me = { base, size }; + if (!PrefetchVirtualMemory (GetCurrentProcess (), 1, &me, 0) + && GetLastError () != ERROR_PROC_NOT_FOUND) + { + /* FIXME 2015-08-27: On W10 build 10240 under WOW64, + PrefetchVirtualMemory always returns ERROR_INVALID_PARAMETER + for some reason. If we're running on W10 WOW64, ignore this + error for now. There's an open case at Microsoft for this. */ + if (!wincap.has_broken_prefetchvm () + || GetLastError () != ERROR_INVALID_PARAMETER) + ret = EINVAL; + } + } + break; + case POSIX_MADV_DONTNEED: + { + /* Align address and length values to page size. */ + size_t pagesize = wincap.allocation_granularity (); + PVOID base = (PVOID) rounddown ((uintptr_t) addr, pagesize); + SIZE_T size = roundup2 (((uintptr_t) addr - (uintptr_t) base) + + len, pagesize); + DWORD err = DiscardVirtualMemory (base, size); + /* DiscardVirtualMemory is unfortunately pretty crippled: + On copy-on-write pages it returns ERROR_INVALID_PARAMETER, on + any file-backed memory map it returns ERROR_USER_MAPPED_FILE. + Since POSIX_MADV_DONTNEED is advisory only anyway, let them + slip through. */ + switch (err) + { + case ERROR_PROC_NOT_FOUND: + case ERROR_USER_MAPPED_FILE: + case 0: + break; + case ERROR_INVALID_PARAMETER: { - ret = ENOMEM; - break; + ret = EINVAL; + /* Check if the region contains copy-on-write pages.*/ + for (p = (char *) addr, endp = p + len; + p < endp; + p = (char *) m.BaseAddress + m.RegionSize) + { + if (VirtualQuery (p, &m, sizeof m) + && m.State == MEM_COMMIT + && m.Protect + & (PAGE_EXECUTE_WRITECOPY | PAGE_WRITECOPY)) + { + /* Yes, let this slip. */ + ret = 0; + break; + } + } } - p = (char *) m.BaseAddress + m.RegionSize; - } - ret = 0; + break; + default: + ret = geterrno_from_win_error (err); + break; + } + } + break; + default: + break; } - +out: syscall_printf ("%d = posix_madvise(%p, %lu, %d)", ret, addr, len, advice); - /* Eventually do nothing. */ - return 0; + return ret; } /* |