Reviewed-by: Liming Gao <[email protected]> -----Original Message----- From: Ard Biesheuvel [mailto:[email protected]] Sent: Friday, February 24, 2017 6:29 AM To: Laszlo Ersek <[email protected]> Cc: [email protected] <[email protected]>; Gao, Liming <[email protected]>; Zhu, Yonghong <[email protected]> Subject: Re: [PATCH] BaseTools: GCC: move most AutoGen.obj contents back to .data section
On 23 February 2017 at 19:53, Laszlo Ersek <[email protected]> wrote: > On 02/23/17 19:30, Ard Biesheuvel wrote: >> The generated AutoGen.c files mostly contain read-only data, but due to >> lacking annotations, all of it is emitted into the .data section by the >> compiler. >> >> Given that GUIDs are UEFI's gaffer tape, having writable GUIDs is a >> security hazard, and this was the main rationale for putting AutoGen.obj >> in the .text section. However, as it turns out, patchable PCDs are emitted >> there as well, which can legally be modified at runtime. >> >> So update the wildcard pattern to only match g...Guid sections, and move >> everything else back to .data (Note that this relies on -fdata-sections, >> without that option, everything is emitted into .data) >> >> Contributed-under: TianoCore Contribution Agreement 1.0 >> Signed-off-by: Ard Biesheuvel <[email protected]> >> --- >> BaseTools/Scripts/GccBase.lds | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/BaseTools/Scripts/GccBase.lds b/BaseTools/Scripts/GccBase.lds >> index 900848747144..41e5c0b4a769 100644 >> --- a/BaseTools/Scripts/GccBase.lds >> +++ b/BaseTools/Scripts/GccBase.lds >> @@ -32,11 +32,14 @@ SECTIONS { >> *(.got .got.*) >> >> /* >> - * The contents of AutoGen.c files are constant from the POV of the >> program, >> - * but most of its contents end up in .data or .bss by default since >> few of >> + * The contents of AutoGen.c files are mostly constant from the POV of >> the >> + * program, but most of it ends up in .data or .bss by default since >> few of >> * the variable definitions that get emitted are declared as CONST. >> + * Unfortunately, we cannot pull it into the .text section entirely, >> since >> + * patchable PCDs are also emitted here, but we can at least move all >> of the >> + * emitted GUIDs here. >> */ >> - *:AutoGen.obj(.data .data.* .bss .bss.*) >> + *:AutoGen.obj(.data.g*Guid) >> } >> >> /* >> > > Do you agree to add: > > Fixes: 233bd25b000f92fc4bbe181fa48edcd72808de8e > > to the commit message, or to reference that commit in some other form? > Yes, that makes sense. > Either way: > > Tested-by: Laszlo Ersek <[email protected]> > > Thank you very much for the quick fix! No problem. _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
