On Wed, 22 Jul 2020, Kito Cheng wrote:
> - Most KASAN function don't need any porting anything in back-end
> except asan stack protection.
>
> - However kernel will given shadow offset when enable asan stack
> protection, so eveything in KASAN can work if shadow offset is given.
>
> - Verified with x86 and risc-v.
>
> - Verified with RISC-V linux kernel.
>
> OK for trunk and GCC 10 branch?
If it is approved please wait until after the GCC 10.2 release tomorrow.
Richard.
> gcc/ChangeLog:
>
> PR target/96260
> * asan.c (asan_shadow_offset_set_p): New.
> * asan.h (asan_shadow_offset_set_p): Ditto.
> * toplev.c (process_options): Allow -fsanitize=kernel-address
> even TARGET_ASAN_SHADOW_OFFSET not implemented, only check when
> asan stack protection is enabled.
>
> gcc/testsuite/ChangeLog:
>
> PR target/96260
> * gcc.target/riscv/pr91441.c: Update warning message.
> * gcc.target/riscv/pr96260.c: New.
> ---
> gcc/asan.c | 6 ++++++
> gcc/asan.h | 2 ++
> gcc/testsuite/gcc.target/riscv/pr91441.c | 2 +-
> gcc/testsuite/gcc.target/riscv/pr96260.c | 9 +++++++++
> gcc/toplev.c | 21 ++++++++++++++++++++-
> 5 files changed, 38 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/riscv/pr96260.c
>
> diff --git a/gcc/asan.c b/gcc/asan.c
> index 9c9aa4cae358..2e759540246f 100644
> --- a/gcc/asan.c
> +++ b/gcc/asan.c
> @@ -344,6 +344,12 @@ asan_shadow_offset ()
> return asan_shadow_offset_value;
> }
>
> +/* Returns Asan shadow offset has been set. */
> +bool asan_shadow_offset_set_p ()
> +{
> + return asan_shadow_offset_computed;
> +}
> +
> alias_set_type asan_shadow_set = -1;
>
> /* Pointer types to 1, 2 or 4 byte integers in shadow memory. A separate
> diff --git a/gcc/asan.h b/gcc/asan.h
> index 9efd33f9b86b..114b457ef91c 100644
> --- a/gcc/asan.h
> +++ b/gcc/asan.h
> @@ -129,6 +129,8 @@ asan_var_and_redzone_size (unsigned HOST_WIDE_INT size)
>
> extern bool set_asan_shadow_offset (const char *);
>
> +extern bool asan_shadow_offset_set_p ();
> +
> extern void set_sanitized_sections (const char *);
>
> extern bool asan_sanitize_stack_p (void);
> diff --git a/gcc/testsuite/gcc.target/riscv/pr91441.c
> b/gcc/testsuite/gcc.target/riscv/pr91441.c
> index 593a2972a0f0..2403c98bb703 100644
> --- a/gcc/testsuite/gcc.target/riscv/pr91441.c
> +++ b/gcc/testsuite/gcc.target/riscv/pr91441.c
> @@ -7,4 +7,4 @@ int *f( int a)
> {
> return bar(&a);
> }
> -/* { dg-warning ".'-fsanitize=address' and '-fsanitize=kernel-address' are
> not supported for this target" "" { target *-*-* } 0 } */
> +/* { dg-warning ".'-fsanitize=kernel-address' with stack protection is not
> supported without '-fasan-shadow-offset=' for this target." "" { target *-*-*
> } 0 } */
> diff --git a/gcc/testsuite/gcc.target/riscv/pr96260.c
> b/gcc/testsuite/gcc.target/riscv/pr96260.c
> new file mode 100644
> index 000000000000..229997f877b7
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/pr96260.c
> @@ -0,0 +1,9 @@
> +/* PR target/96260 */
> +/* { dg-do compile } */
> +/* { dg-options "--param asan-stack=1 -fsanitize=kernel-address
> -fasan-shadow-offset=0x100000" } */
> +
> +int *bar(int *);
> +int *f( int a)
> +{
> + return bar(&a);
> +}
> diff --git a/gcc/toplev.c b/gcc/toplev.c
> index 95eea63380f6..48f13d282c52 100644
> --- a/gcc/toplev.c
> +++ b/gcc/toplev.c
> @@ -1835,7 +1835,7 @@ process_options (void)
> /* Address Sanitizer needs porting to each target architecture. */
>
> if ((flag_sanitize & SANITIZE_ADDRESS)
> - && (!FRAME_GROWS_DOWNWARD || targetm.asan_shadow_offset == NULL))
> + && !FRAME_GROWS_DOWNWARD)
> {
> warning_at (UNKNOWN_LOCATION, 0,
> "%<-fsanitize=address%> and %<-fsanitize=kernel-address%> "
> @@ -1843,6 +1843,25 @@ process_options (void)
> flag_sanitize &= ~SANITIZE_ADDRESS;
> }
>
> + if ((flag_sanitize & SANITIZE_USER_ADDRESS)
> + && targetm.asan_shadow_offset == NULL)
> + {
> + warning_at (UNKNOWN_LOCATION, 0,
> + "%<-fsanitize=address%> not supported for this target");
> + flag_sanitize &= ~SANITIZE_ADDRESS;
> + }
> +
> + if ((flag_sanitize & SANITIZE_KERNEL_ADDRESS)
> + && (targetm.asan_shadow_offset == NULL && param_asan_stack
> + && !asan_shadow_offset_set_p ()))
> + {
> + warning_at (UNKNOWN_LOCATION, 0,
> + "%<-fsanitize=kernel-address%> with stack protection "
> + "is not supported without %<-fasan-shadow-offset=%> "
> + "for this target.");
> + flag_sanitize &= ~SANITIZE_ADDRESS;
> + }
> +
> /* Do not use IPA optimizations for register allocation if profiler is
> active
> or patchable function entries are inserted for run-time instrumentation
> or port does not emit prologue and epilogue as RTL. */
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
