Alexandre Julliard : ntdll: Add a helper function for setting bits in page protection bytes.
Module: wine Branch: master Commit: e4b5e5da8ad0adc0cbb60b8937bc4406a21ae38d URL: http://source.winehq.org/git/wine.git/?a=commit;h=e4b5e5da8ad0adc0cbb60b8937... Author: Alexandre Julliard <julliard(a)winehq.org> Date: Tue Sep 5 14:18:06 2017 +0200 ntdll: Add a helper function for setting bits in page protection bytes. Signed-off-by: Alexandre Julliard <julliard(a)winehq.org> --- dlls/ntdll/virtual.c | 63 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 36 insertions(+), 27 deletions(-) diff --git a/dlls/ntdll/virtual.c b/dlls/ntdll/virtual.c index d681b4c..d34fbed 100644 --- a/dlls/ntdll/virtual.c +++ b/dlls/ntdll/virtual.c @@ -177,6 +177,21 @@ static void set_page_vprot( struct file_view *view, const void *addr, size_t siz /*********************************************************************** + * set_page_vprot_bits + * + * Set or clear bits in a range of page protection bytes. + */ +static void set_page_vprot_bits( struct file_view *view, const void *addr, size_t size, + BYTE set, BYTE clear ) +{ + BYTE *ptr = view->prot + (((const char *)addr - (const char *)view->base) >> page_shift); + size_t i; + + for (i = 0; i < ROUND_SIZE( addr, size ) >> page_shift; i++) ptr[i] = (ptr[i] & ~clear) | set; +} + + +/*********************************************************************** * VIRTUAL_GetProtStr */ static const char *VIRTUAL_GetProtStr( BYTE prot ) @@ -717,14 +732,12 @@ static BOOL VIRTUAL_SetProt( struct file_view *view, /* [in] Pointer to view */ UINT i, count; char *addr = base; int prot; - BYTE *p = view->prot + ((addr - (char *)view->base) >> page_shift); - p[0] = vprot | (p[0] & VPROT_WRITEWATCH); - unix_prot = VIRTUAL_GetUnixProt( p[0] ); + set_page_vprot_bits( view, base, size, vprot & ~VPROT_WRITEWATCH, ~vprot & ~VPROT_WRITEWATCH ); + unix_prot = VIRTUAL_GetUnixProt( get_page_vprot( view, addr )); for (count = i = 1; i < size >> page_shift; i++, count++) { - p[i] = vprot | (p[i] & VPROT_WRITEWATCH); - prot = VIRTUAL_GetUnixProt( p[i] ); + prot = VIRTUAL_GetUnixProt( get_page_vprot( view, addr + (count << page_shift) )); if (prot == unix_prot) continue; mprotect_exec( addr, count << page_shift, unix_prot, view->protect ); addr += count << page_shift; @@ -767,14 +780,12 @@ static void reset_write_watches( struct file_view *view, void *base, SIZE_T size SIZE_T i, count; int prot, unix_prot; char *addr = base; - BYTE *p = view->prot + ((addr - (char *)view->base) >> page_shift); - p[0] |= VPROT_WRITEWATCH; - unix_prot = VIRTUAL_GetUnixProt( p[0] ); + set_page_vprot_bits( view, base, size, VPROT_WRITEWATCH, 0 ); + unix_prot = VIRTUAL_GetUnixProt( get_page_vprot( view, addr )); for (count = i = 1; i < size >> page_shift; i++, count++) { - p[i] |= VPROT_WRITEWATCH; - prot = VIRTUAL_GetUnixProt( p[i] ); + prot = VIRTUAL_GetUnixProt( get_page_vprot( view, addr + (count << page_shift) )); if (prot == unix_prot) continue; mprotect_exec( addr, count << page_shift, unix_prot, view->protect ); addr += count << page_shift; @@ -1051,7 +1062,7 @@ static SIZE_T get_committed_size( struct file_view *view, void *base, BYTE *vpro if (reply->committed) { *vprot |= VPROT_COMMITTED; - for (i = 0; i < ret >> page_shift; i++) view->prot[start+i] |= VPROT_COMMITTED; + set_page_vprot_bits( view, base, ret, VPROT_COMMITTED, 0 ); } } } @@ -1074,9 +1085,7 @@ static NTSTATUS decommit_pages( struct file_view *view, size_t start, size_t siz { if (wine_anon_mmap( (char *)view->base + start, size, PROT_NONE, MAP_FIXED ) != (void *)-1) { - BYTE *p = view->prot + (start >> page_shift); - size >>= page_shift; - while (size--) *p++ &= ~VPROT_COMMITTED; + set_page_vprot_bits( view, (char *)view->base + start, size, 0, VPROT_COMMITTED ); return STATUS_SUCCESS; } return FILE_GetNtStatus(); @@ -1610,20 +1619,20 @@ NTSTATUS virtual_handle_fault( LPCVOID addr, DWORD err, BOOL on_signal_stack ) if ((view = VIRTUAL_FindView( addr, 0 ))) { void *page = ROUND_ADDR( addr, page_mask ); - BYTE *vprot = &view->prot[((const char *)page - (const char *)view->base) >> page_shift]; + BYTE vprot = get_page_vprot( view, page ); if ((err & EXCEPTION_WRITE_FAULT) && (view->protect & VPROT_WRITEWATCH)) { - if (*vprot & VPROT_WRITEWATCH) + if (vprot & VPROT_WRITEWATCH) { - *vprot &= ~VPROT_WRITEWATCH; - VIRTUAL_SetProt( view, page, page_size, *vprot ); + set_page_vprot_bits( view, page, page_size, 0, VPROT_WRITEWATCH ); + VIRTUAL_SetProt( view, page, page_size, get_page_vprot( view, page )); } /* ignore fault if page is writable now */ - if (VIRTUAL_GetUnixProt( *vprot ) & PROT_WRITE) ret = STATUS_SUCCESS; + if (VIRTUAL_GetUnixProt( get_page_vprot( view, page )) & PROT_WRITE) ret = STATUS_SUCCESS; } - if (!on_signal_stack && (*vprot & VPROT_GUARD)) + if (!on_signal_stack && (vprot & VPROT_GUARD)) { - VIRTUAL_SetProt( view, page, page_size, *vprot & ~VPROT_GUARD ); + VIRTUAL_SetProt( view, page, page_size, vprot & ~VPROT_GUARD ); ret = STATUS_GUARD_PAGE_VIOLATION; } } @@ -1812,24 +1821,24 @@ SIZE_T virtual_uninterrupted_write_memory( void *addr, const void *buffer, SIZE_ while (bytes_written < size) { void *page = ROUND_ADDR( addr, page_mask ); - BYTE *p = view->prot + (((const char *)page - (const char *)view->base) >> page_shift); + BYTE vprot = get_page_vprot( view, page ); SIZE_T block_size; /* If the page is not writable then check for write watches * before giving up. This can be done without raising a real * exception. Similar to virtual_handle_fault. */ - if (!(VIRTUAL_GetUnixProt( *p ) & PROT_WRITE)) + if (!(VIRTUAL_GetUnixProt( vprot ) & PROT_WRITE)) { if (!(view->protect & VPROT_WRITEWATCH)) break; - if (*p & VPROT_WRITEWATCH) + if (vprot & VPROT_WRITEWATCH) { - *p &= ~VPROT_WRITEWATCH; - VIRTUAL_SetProt( view, page, page_size, *p ); + set_page_vprot_bits( view, page, page_size, 0, VPROT_WRITEWATCH ); + VIRTUAL_SetProt( view, page, page_size, get_page_vprot( view, page )); } /* ignore fault if page is writable now */ - if (!(VIRTUAL_GetUnixProt( *p ) & PROT_WRITE)) + if (!(VIRTUAL_GetUnixProt( get_page_vprot( view, page )) & PROT_WRITE)) break; }
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Alexandre Julliard