Re: [PATCH] ntdll: set correct protection flags on sections in builtin DLLs

[Alexandre Julliard]

Marcus Meissner  writes:
> @@ -1406,7 +1409,18 @@ static void load_builtin_callback( void *module, const char *filename )
>      }
>      virtual_create_system_view( module, nt->OptionalHeader.SizeOfImage,
>                                  VPROT_SYSTEM | VPROT_IMAGE | VPROT_COMMITTED |
> -
>                            VPROT_READ | VPROT_WRITECOPY | VPROT_EXEC );
> -
>                            VPROT_READ | VPROT_WRITECOPY | VPROT_EXEC, &view );
> -
> - sec = (IMAGE_SECTION_HEADER*)((char*)&nt->OptionalHeader+nt->FileHeader.SizeOfOptionalHeader);
> - for (i=0;i<nt->FileHeader.NumberOfSections;i++) {
> -
>    DWORD flags = VPROT_SYSTEM | VPROT_IMAGE | VPROT_COMMITTED;
> -
> -
>    if (sec[i].Characteristics & IMAGE_SCN_MEM_EXECUTE) flags |= VPROT_EXEC;
> -
>    if (sec[i].Characteristics & IMAGE_SCN_MEM_READ) flags |= VPROT_READ;
> -
>    if (sec[i].Characteristics & IMAGE_SCN_MEM_WRITE) flags |= VPROT_WRITE;
> -
>    if (sec[i].Characteristics & IMAGE_SCN_MEM_SHARED) flags |= VPROT_WRITECOPY;
> -
>    VIRTUAL_SetProt( view, (char*)module + sec[i].VirtualAddress, sec[i].Misc.VirtualSize, flags );

I don't think you want to actually change the permissions, our headers
don't necessarily match the real ELF sections.

(BTW, could you please convince your mailer to set a valid Message-Id?)

[PATCH] ntdll: set correct protection flags on sections in builtin DLLs

[Marcus Meissner]

On Mon, Aug 23, 2010 at 03:43:35PM +0200, Alexandre Julliard wrote:
> Marcus Meissner  writes:
> > @@ -1406,7 +1409,18 @@ static void load_builtin_callback( void *module, const char *filename )
> >      }
> >      virtual_create_system_view( module, nt->OptionalHeader.SizeOfImage,
> >                                  VPROT_SYSTEM | VPROT_IMAGE | VPROT_COMMITTED |
> > -
> >                            VPROT_READ | VPROT_WRITECOPY | VPROT_EXEC );
> > -
> >                            VPROT_READ | VPROT_WRITECOPY | VPROT_EXEC, &view );
> > -
> > - sec = (IMAGE_SECTION_HEADER*)((char*)&nt->OptionalHeader+nt->FileHeader.SizeOfOptionalHeader);
> > - for (i=0;i<nt->FileHeader.NumberOfSections;i++) {
> > -
> >    DWORD flags = VPROT_SYSTEM | VPROT_IMAGE | VPROT_COMMITTED;
> > -
> > -
> >    if (sec[i].Characteristics & IMAGE_SCN_MEM_EXECUTE) flags |= VPROT_EXEC;
> > -
> >    if (sec[i].Characteristics & IMAGE_SCN_MEM_READ) flags |= VPROT_READ;
> > -
> >    if (sec[i].Characteristics & IMAGE_SCN_MEM_WRITE) flags |= VPROT_WRITE;
> > -
> >    if (sec[i].Characteristics & IMAGE_SCN_MEM_SHARED) flags |= VPROT_WRITECOPY;
> > -
> >    VIRTUAL_SetProt( view, (char*)module + sec[i].VirtualAddress, sec[i].Misc.VirtualSize, flags );
>
> I don't think you want to actually change the permissions, our headers
> don't necessarily match the real ELF sections.

So a call to change the protection without calling mprotect() in the end?
like VIRTUAL_SetProtData() or something?
> (BTW, could you please convince your mailer to set a valid Message-Id?)

I am bouncing them from the "git format-patch origin" created files currently.

Ciao, Macus

[PATCH] ntdll: set correct protection flags on sections in builtin DLLs

[Alexandre Julliard]

Marcus Meissner  writes:
> So a call to change the protection without calling mprotect() in the end?
> like VIRTUAL_SetProtData() or something?

Something like that yes (and please do it all in virtual.c, that's not
the sort of function you want to make global).