LGTM.
Verified with Fedora rawhide image running on qemu, kernel version is 5.5.0,
I got slightly different gcc testsuite result, but after reviewing all
failed cases,
it should not be a blocker for this patch.
It seems environment issue, some minor issues like stack
unwinding or library search path.
e.g
- ld complain cannot find -latomic
- Stack unwinding result not show main in asan report.
=== gcc Summary ===
# of expected passes 2672
# of unexpected failures 25
# of unresolved testcases 14
# of unsupported tests 224
=== g++ Summary ===
# of expected passes 1967
# of unexpected failures 20
# of unresolved testcases 15
# of unsupported tests 175
On Thu, Nov 5, 2020 at 4:11 AM Jim Wilson <j...@sifive.com> wrote:
>
> On Wed, Oct 28, 2020 at 4:59 PM Jim Wilson <j...@sifive.com> wrote:
>
> > We have only riscv64 asan support, there is no riscv32 support as yet. So
> > I
> > need to be able to conditionally enable asan support for the riscv
> > target. I
> > implemented this by returning zero from the asan_shadow_offset function.
> > This
> > requires a change to toplev.c and docs in target.def.
> >
> > The asan support works on a 5.5 kernel, but does not work on a 4.15 kernel.
> > The problem is that the asan high memory region is a small wedge below
> > 0x4000000000. The new kernel puts shared libraries at 0x3fffffffff and
> > going
> > down which works. But the old kernel puts shared libraries at 0x2000000000
> > and going up which does not work, as it isn't in any recognized memory
> > region. This might be fixable with more asan work, but we don't really
> > need
> > support for old kernel versions.
> >
> > The asan port is curious in that it uses 1<<29 for the shadow offset, but
> > all
> > other 64-bit targets use a number larger than 1<<32. But what we have is
> > working OK for now.
> >
> > I did a make check RUNTESTFLAGS="asan.exp" on Fedora rawhide image running
> > on
> > qemu and the results look reasonable.
> >
> > === gcc Summary ===
> >
> > # of expected passes 1905
> > # of unexpected failures 11
> > # of unsupported tests 224
> >
> > === g++ Summary ===
> >
> > # of expected passes 2002
> > # of unexpected failures 6
> > # of unresolved testcases 1
> > # of unsupported tests 175
> >
> > OK?
> >
> > Jim
> >
> > 2020-10-28 Jim Wilson <j...@sifive.com>
> >
> > gcc/
> > * config/riscv/riscv.c (riscv_asan_shadow_offset): New.
> > (TARGET_ASAN_SHADOW_OFFSET): New.
> > * doc/tm.texi: Regenerated.
> > * target.def (asan_shadow_offset); Mention that it can return zero.
> > * toplev.c (process_options): Check for and handle zero return from
> > targetm.asan_shadow_offset call.
> >
> > Co-Authored-By: cooper.joshua <cooper.jos...@linux.alibaba.com>
> > ---
> > gcc/config/riscv/riscv.c | 16 ++++++++++++++++
> > gcc/doc/tm.texi | 3 ++-
> > gcc/target.def | 3 ++-
> > gcc/toplev.c | 3 ++-
> > 4 files changed, 22 insertions(+), 3 deletions(-)
> >
> > diff --git a/gcc/config/riscv/riscv.c b/gcc/config/riscv/riscv.c
> > index 989a9f15250..6909e200de1 100644
> > --- a/gcc/config/riscv/riscv.c
> > +++ b/gcc/config/riscv/riscv.c
> > @@ -5299,6 +5299,19 @@ riscv_gpr_save_operation_p (rtx op)
> > return true;
> > }
> >
> > +/* Implement TARGET_ASAN_SHADOW_OFFSET. */
> > +
> > +static unsigned HOST_WIDE_INT
> > +riscv_asan_shadow_offset (void)
> > +{
> > + /* We only have libsanitizer support for RV64 at present.
> > +
> > + This number must match kRiscv*_ShadowOffset* in the file
> > + libsanitizer/asan/asan_mapping.h which is currently 1<<29 for rv64,
> > + even though 1<<36 makes more sense. */
> > + return TARGET_64BIT ? (HOST_WIDE_INT_1 << 29) : 0;
> > +}
> > +
> > /* Initialize the GCC target structure. */
> > #undef TARGET_ASM_ALIGNED_HI_OP
> > #define TARGET_ASM_ALIGNED_HI_OP "\t.half\t"
> > @@ -5482,6 +5495,9 @@ riscv_gpr_save_operation_p (rtx op)
> > #undef TARGET_NEW_ADDRESS_PROFITABLE_P
> > #define TARGET_NEW_ADDRESS_PROFITABLE_P riscv_new_address_profitable_p
> >
> > +#undef TARGET_ASAN_SHADOW_OFFSET
> > +#define TARGET_ASAN_SHADOW_OFFSET riscv_asan_shadow_offset
> > +
> > struct gcc_target targetm = TARGET_INITIALIZER;
> >
> > #include "gt-riscv.h"
> > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> > index 24c37f655c8..39c596b647a 100644
> > --- a/gcc/doc/tm.texi
> > +++ b/gcc/doc/tm.texi
> > @@ -12078,7 +12078,8 @@ is zero, which disables this optimization.
> > @deftypefn {Target Hook} {unsigned HOST_WIDE_INT}
> > TARGET_ASAN_SHADOW_OFFSET (void)
> > Return the offset bitwise ored into shifted address to get corresponding
> > Address Sanitizer shadow memory address. NULL if Address Sanitizer is not
> > -supported by the target.
> > +supported by the target. May return 0 if Address Sanitizer is not
> > supported
> > +by a subtarget.
> > @end deftypefn
> >
> > @deftypefn {Target Hook} {unsigned HOST_WIDE_INT} TARGET_MEMMODEL_CHECK
> > (unsigned HOST_WIDE_INT @var{val})
> > diff --git a/gcc/target.def b/gcc/target.def
> > index ed2da154e30..268b56b6ebd 100644
> > --- a/gcc/target.def
> > +++ b/gcc/target.def
> > @@ -4452,7 +4452,8 @@ DEFHOOK
> > (asan_shadow_offset,
> > "Return the offset bitwise ored into shifted address to get
> > corresponding\n\
> > Address Sanitizer shadow memory address. NULL if Address Sanitizer is
> > not\n\
> > -supported by the target.",
> > +supported by the target. May return 0 if Address Sanitizer is not
> > supported\n\
> > +by a subtarget.",
> > unsigned HOST_WIDE_INT, (void),
> > NULL)
> >
> > diff --git a/gcc/toplev.c b/gcc/toplev.c
> > index 20e231f4d2a..cf89598252c 100644
> > --- a/gcc/toplev.c
> > +++ b/gcc/toplev.c
> > @@ -1834,7 +1834,8 @@ process_options (void)
> > }
> >
> > if ((flag_sanitize & SANITIZE_USER_ADDRESS)
> > - && targetm.asan_shadow_offset == NULL)
> > + && ((targetm.asan_shadow_offset == NULL)
> > + || (targetm.asan_shadow_offset () == 0)))
> > {
> > warning_at (UNKNOWN_LOCATION, 0,
> > "%<-fsanitize=address%> not supported for this target");
> > --
> > 2.17.1
> >
> >
