| Message ID | 20201230064348.376092-2-siddhesh@sourceware.org |
|---|---|
| State | New |
| Headers | show |
| Series | _FORTIFY_SOURCE=3 | expand |
On 30/12/2020 03:43, Siddhesh Poyarekar wrote: > Make the _FORTIFY_SOURCE macro soup in features.h warn about > unsupported fortification levels. For example, it will warn about > _FORTIFY_SOURCE=3 and over with an indication of which level has been > selected. > > Co-authored-by: Paul Eggert <eggert@cs.ucla.edu> LGTM, although I think the NEWS entry should move to the second patch. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > NEWS | 6 ++++++ > include/features.h | 3 +++ > manual/creature.texi | 3 ++- > 3 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/NEWS b/NEWS > index 86e05fb023..8e02dbd0f7 100644 > --- a/NEWS > +++ b/NEWS > @@ -28,6 +28,12 @@ Major new features: > The 32-bit RISC-V port requires at least Linux 5.4, GCC 7.1 and binutils > 2.28. > > +* A new fortification level _FORTIFY_SOURCE=3 is available. At this level, > + glibc may use additional checks that may have an additional performance > + overhead. At present these checks are available only on LLVM 9 and later. > + The latest GCC available at this time (10.2) does not support this level of > + fortification. > + > Deprecated and removed features, and other changes affecting compatibility: > > * The mallinfo function is marked deprecated. Callers should call Maybe move this NEWS entry to second patch, where this is actually enabled? > diff --git a/include/features.h b/include/features.h > index f3e62d3362..540230b90b 100644 > --- a/include/features.h > +++ b/include/features.h > @@ -398,6 +398,9 @@ > # elif !__GNUC_PREREQ (4, 1) > # warning _FORTIFY_SOURCE requires GCC 4.1 or later > # elif _FORTIFY_SOURCE > 1 > +# if _FORTIFY_SOURCE > 2 > +# warning _FORTIFY_SOURCE > 2 is treated like 2 on this platform > +# endif > # define __USE_FORTIFY_LEVEL 2 > # else > # define __USE_FORTIFY_LEVEL 1 > diff --git a/manual/creature.texi b/manual/creature.texi > index be5050468b..31208ccb2b 100644 > --- a/manual/creature.texi > +++ b/manual/creature.texi > @@ -254,7 +254,8 @@ included. > @standards{GNU, (none)} > If this macro is defined to @math{1}, security hardening is added to > various library functions. If defined to @math{2}, even stricter > -checks are applied. > +checks are applied. If defined to @math{3}, @theglibc{} may also use > +checks that may have an additional performance overhead. > @end defvr > > @defvr Macro _REENTRANT >
On 12/31/20 4:15 PM, Adhemerval Zanella wrote: > > > On 30/12/2020 03:43, Siddhesh Poyarekar wrote: >> Make the _FORTIFY_SOURCE macro soup in features.h warn about >> unsupported fortification levels. For example, it will warn about >> _FORTIFY_SOURCE=3 and over with an indication of which level has been >> selected. >> >> Co-authored-by: Paul Eggert <eggert@cs.ucla.edu> > > LGTM, although I think the NEWS entry should move to the second patch. > Oops, yes. I've moved the creatures.texi as well as NEWS content to 2/4 before commit. Thanks, Siddhesh
diff --git a/NEWS b/NEWS index 86e05fb023..8e02dbd0f7 100644 --- a/NEWS +++ b/NEWS @@ -28,6 +28,12 @@ Major new features: The 32-bit RISC-V port requires at least Linux 5.4, GCC 7.1 and binutils 2.28. +* A new fortification level _FORTIFY_SOURCE=3 is available. At this level, + glibc may use additional checks that may have an additional performance + overhead. At present these checks are available only on LLVM 9 and later. + The latest GCC available at this time (10.2) does not support this level of + fortification. + Deprecated and removed features, and other changes affecting compatibility: * The mallinfo function is marked deprecated. Callers should call diff --git a/include/features.h b/include/features.h index f3e62d3362..540230b90b 100644 --- a/include/features.h +++ b/include/features.h @@ -398,6 +398,9 @@ # elif !__GNUC_PREREQ (4, 1) # warning _FORTIFY_SOURCE requires GCC 4.1 or later # elif _FORTIFY_SOURCE > 1 +# if _FORTIFY_SOURCE > 2 +# warning _FORTIFY_SOURCE > 2 is treated like 2 on this platform +# endif # define __USE_FORTIFY_LEVEL 2 # else # define __USE_FORTIFY_LEVEL 1 diff --git a/manual/creature.texi b/manual/creature.texi index be5050468b..31208ccb2b 100644 --- a/manual/creature.texi +++ b/manual/creature.texi @@ -254,7 +254,8 @@ included. @standards{GNU, (none)} If this macro is defined to @math{1}, security hardening is added to various library functions. If defined to @math{2}, even stricter -checks are applied. +checks are applied. If defined to @math{3}, @theglibc{} may also use +checks that may have an additional performance overhead. @end defvr @defvr Macro _REENTRANT