From 7656f468a405a0b399994f0cbb9bd8388100cfde Mon Sep 17 00:00:00 2001 From: Andrew Wesie Date: Fri, 24 Apr 2020 14:55:14 -0500 Subject: [PATCH] ntdll: Track if a WRITECOPY page has been modified. Once a WRITECOPY page is modified, it should be mapped as if it is a normal read-write page. Signed-off-by: Andrew Wesie --- dlls/ntdll/virtual.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/dlls/ntdll/virtual.c b/dlls/ntdll/virtual.c index fa39a67b9ca..b5baa4c6242 100644 --- a/dlls/ntdll/virtual.c +++ b/dlls/ntdll/virtual.c @@ -84,6 +84,7 @@ struct file_view #define VPROT_GUARD 0x10 #define VPROT_COMMITTED 0x20 #define VPROT_WRITEWATCH 0x40 +#define VPROT_WRITTEN 0x80 /* per-mapping protection flags */ #define VPROT_SYSTEM 0x0200 /* system view (underlying mmap not under our control) */ @@ -355,7 +356,7 @@ static int VIRTUAL_GetUnixProt( BYTE vprot ) #if defined(__i386__) if (vprot & VPROT_WRITECOPY) { - if (experimental_WRITECOPY()) + if (experimental_WRITECOPY() && !(vprot & VPROT_WRITTEN)) prot = (prot & ~PROT_WRITE) | PROT_READ; else prot |= PROT_WRITE | PROT_READ; @@ -918,7 +919,11 @@ static NTSTATUS create_view( struct file_view **view_ret, void *base, size_t siz */ static DWORD VIRTUAL_GetWin32Prot( BYTE vprot, unsigned int map_prot ) { - DWORD ret = VIRTUAL_Win32Flags[vprot & 0x0f]; + DWORD ret; + + if ((vprot & VPROT_WRITECOPY) && (vprot & VPROT_WRITTEN)) + vprot = (vprot & ~VPROT_WRITECOPY) | VPROT_WRITE; + ret = VIRTUAL_Win32Flags[vprot & 0x0f]; if (vprot & VPROT_GUARD) ret |= PAGE_GUARD; if (map_prot & SEC_NOCACHE) ret |= PAGE_NOCACHE; return ret; @@ -1042,7 +1047,7 @@ static BOOL VIRTUAL_SetProt( struct file_view *view, /* [in] Pointer to view */ if (view->protect & VPROT_WRITEWATCH) { /* each page may need different protections depending on write watch flag */ - set_page_vprot_bits( base, size, vprot & ~VPROT_WRITEWATCH, ~vprot & ~VPROT_WRITEWATCH ); + set_page_vprot_bits( base, size, vprot & ~VPROT_WRITEWATCH, ~vprot & ~(VPROT_WRITEWATCH|VPROT_WRITTEN) ); mprotect_range( base, size, 0, 0 ); return TRUE; } @@ -1058,10 +1063,18 @@ static BOOL VIRTUAL_SetProt( struct file_view *view, /* [in] Pointer to view */ return TRUE; } + /* check that we can map this memory with PROT_WRITE since we cannot fail later */ + if (vprot & VPROT_WRITECOPY) + unix_prot |= PROT_WRITE; + if (mprotect_exec( base, size, unix_prot )) /* FIXME: last error */ return FALSE; - set_page_vprot( base, size, vprot ); + /* each page may need different protections depending on writecopy */ + set_page_vprot_bits( base, size, vprot, ~vprot & ~VPROT_WRITTEN ); + if (vprot & VPROT_WRITECOPY) + mprotect_range( base, size, 0, 0 ); + return TRUE; } @@ -2319,7 +2332,7 @@ NTSTATUS virtual_handle_fault( LPCVOID addr, DWORD err, BOOL on_signal_stack ) } if (vprot & VPROT_WRITECOPY) { - set_page_vprot_bits( page, page_size, VPROT_WRITE, VPROT_WRITECOPY ); + set_page_vprot_bits( page, page_size, VPROT_WRITE | VPROT_WRITTEN, VPROT_WRITECOPY ); mprotect_range( page, page_size, 0, 0 ); } /* ignore fault if page is writable now */ @@ -3265,7 +3278,7 @@ static NTSTATUS get_basic_memory_info( HANDLE process, LPCVOID addr, else if (view->protect & (SEC_FILE | SEC_RESERVE | SEC_COMMIT)) info->Type = MEM_MAPPED; else info->Type = MEM_PRIVATE; for (ptr = base; ptr < base + range_size; ptr += page_size) - if ((get_page_vprot( ptr ) ^ vprot) & ~VPROT_WRITEWATCH) break; + if ((get_page_vprot( ptr ) ^ vprot) & ~(VPROT_WRITEWATCH|VPROT_WRITTEN)) break; info->RegionSize = ptr - base; } server_leave_uninterrupted_section( &csVirtual, &sigset ); -- 2.25.4