* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-12 20:55 [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption Nathan Chancellor
@ 2021-01-12 21:15 ` Nick Desaulniers
2021-01-12 21:37 ` Nathan Chancellor
2021-01-13 0:12 ` [PATCH v2] " Nathan Chancellor
` (2 subsequent siblings)
3 siblings, 1 reply; 14+ messages in thread
From: Nick Desaulniers @ 2021-01-12 21:15 UTC (permalink / raw)
To: Nathan Chancellor; +Cc: Kees Cook, Andrew Morton, LKML, clang-built-linux
On Tue, Jan 12, 2021 at 12:55 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> When building ARCH=mips 32r2el_defconfig with CONFIG_UBSAN_ALIGNMENT:
>
> ld.lld: error: undefined symbol: __ubsan_handle_alignment_assumption
> >>> referenced by slab.h:557 (include/linux/slab.h:557)
> >>> main.o:(do_initcalls) in archive init/built-in.a
> >>> referenced by slab.h:448 (include/linux/slab.h:448)
> >>> do_mounts_rd.o:(rd_load_image) in archive init/built-in.a
> >>> referenced by slab.h:448 (include/linux/slab.h:448)
> >>> do_mounts_rd.o:(identify_ramdisk_image) in archive init/built-in.a
> >>> referenced 1579 more times
>
> Implement this for the kernel based on LLVM's
> handleAlignmentAssumptionImpl because the kernel is not linked against
> the compiler runtime.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1245
> Link: https://github.com/llvm/llvm-project/blob/llvmorg-11.0.1/compiler-rt/lib/ubsan/ubsan_handlers.cpp#L151-L190
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> lib/ubsan.c | 28 ++++++++++++++++++++++++++++
> lib/ubsan.h | 6 ++++++
> 2 files changed, 34 insertions(+)
>
> diff --git a/lib/ubsan.c b/lib/ubsan.c
> index 3e3352f3d0da..a1e6cc9993f8 100644
> --- a/lib/ubsan.c
> +++ b/lib/ubsan.c
> @@ -427,3 +427,31 @@ void __ubsan_handle_load_invalid_value(void *_data, void *val)
> ubsan_epilogue();
> }
> EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
> +
> +void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
> + unsigned long align,
> + unsigned long offset)
> +{
> + struct alignment_assumption_data *data = _data;
> + unsigned long real_ptr;
> +
> + if (suppress_report(&data->location))
> + return;
> +
> + ubsan_prologue(&data->location, "alignment-assumption");
> +
> + if (offset)
> + pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed",
> + align, offset, data->type->type_name);
> + else
> + pr_err("assumption of %lu byte alignment for pointer of type %s failed",
> + align, data->type->type_name);
> +
> + real_ptr = ptr - offset;
> + pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes",
> + offset ? "offset " : "", BIT(ffs(real_ptr)),
if real_ptr is an unsigned long, do we want to use `__ffs(real_ptr) +
1` here rather than ffs which takes an int? It seems the kernel is
missing a definition of ffsl. :(
Otherwise code LGTM.
> + real_ptr & (align - 1));
> +
> + ubsan_epilogue();
> +}
> +EXPORT_SYMBOL(__ubsan_handle_alignment_assumption);
> diff --git a/lib/ubsan.h b/lib/ubsan.h
> index 7b56c09473a9..9a0b71c5ff9f 100644
> --- a/lib/ubsan.h
> +++ b/lib/ubsan.h
> @@ -78,6 +78,12 @@ struct invalid_value_data {
> struct type_descriptor *type;
> };
>
> +struct alignment_assumption_data {
> + struct source_location location;
> + struct source_location assumption_location;
> + struct type_descriptor *type;
> +};
> +
> #if defined(CONFIG_ARCH_SUPPORTS_INT128)
> typedef __int128 s_max;
> typedef unsigned __int128 u_max;
>
> base-commit: 7c53f6b671f4aba70ff15e1b05148b10d58c2837
> --
> 2.30.0
>
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-12 21:15 ` Nick Desaulniers
@ 2021-01-12 21:37 ` Nathan Chancellor
2021-01-12 21:53 ` Nick Desaulniers
0 siblings, 1 reply; 14+ messages in thread
From: Nathan Chancellor @ 2021-01-12 21:37 UTC (permalink / raw)
To: Nick Desaulniers; +Cc: Kees Cook, Andrew Morton, LKML, clang-built-linux
On Tue, Jan 12, 2021 at 01:15:42PM -0800, Nick Desaulniers wrote:
> On Tue, Jan 12, 2021 at 12:55 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > When building ARCH=mips 32r2el_defconfig with CONFIG_UBSAN_ALIGNMENT:
> >
> > ld.lld: error: undefined symbol: __ubsan_handle_alignment_assumption
> > >>> referenced by slab.h:557 (include/linux/slab.h:557)
> > >>> main.o:(do_initcalls) in archive init/built-in.a
> > >>> referenced by slab.h:448 (include/linux/slab.h:448)
> > >>> do_mounts_rd.o:(rd_load_image) in archive init/built-in.a
> > >>> referenced by slab.h:448 (include/linux/slab.h:448)
> > >>> do_mounts_rd.o:(identify_ramdisk_image) in archive init/built-in.a
> > >>> referenced 1579 more times
> >
> > Implement this for the kernel based on LLVM's
> > handleAlignmentAssumptionImpl because the kernel is not linked against
> > the compiler runtime.
> >
> > Link: https://github.com/ClangBuiltLinux/linux/issues/1245
> > Link: https://github.com/llvm/llvm-project/blob/llvmorg-11.0.1/compiler-rt/lib/ubsan/ubsan_handlers.cpp#L151-L190
> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> > ---
> > lib/ubsan.c | 28 ++++++++++++++++++++++++++++
> > lib/ubsan.h | 6 ++++++
> > 2 files changed, 34 insertions(+)
> >
> > diff --git a/lib/ubsan.c b/lib/ubsan.c
> > index 3e3352f3d0da..a1e6cc9993f8 100644
> > --- a/lib/ubsan.c
> > +++ b/lib/ubsan.c
> > @@ -427,3 +427,31 @@ void __ubsan_handle_load_invalid_value(void *_data, void *val)
> > ubsan_epilogue();
> > }
> > EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
> > +
> > +void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
> > + unsigned long align,
> > + unsigned long offset)
> > +{
> > + struct alignment_assumption_data *data = _data;
> > + unsigned long real_ptr;
> > +
> > + if (suppress_report(&data->location))
> > + return;
> > +
> > + ubsan_prologue(&data->location, "alignment-assumption");
> > +
> > + if (offset)
> > + pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed",
> > + align, offset, data->type->type_name);
> > + else
> > + pr_err("assumption of %lu byte alignment for pointer of type %s failed",
> > + align, data->type->type_name);
> > +
> > + real_ptr = ptr - offset;
> > + pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes",
> > + offset ? "offset " : "", BIT(ffs(real_ptr)),
>
> if real_ptr is an unsigned long, do we want to use `__ffs(real_ptr) +
> 1` here rather than ffs which takes an int? It seems the kernel is
> missing a definition of ffsl. :(
Why the + 1? I think if we use __ffs (which it seems like we should), I
think that needs to become
BIT(real_ptr ? __ffs(real_ptr) : 0)
I have made that change locally and will send it for v2 in a day or so
to give Kees some time to check it out.
Thanks for the review!
Nathan
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-12 21:37 ` Nathan Chancellor
@ 2021-01-12 21:53 ` Nick Desaulniers
2021-01-12 22:06 ` Nathan Chancellor
0 siblings, 1 reply; 14+ messages in thread
From: Nick Desaulniers @ 2021-01-12 21:53 UTC (permalink / raw)
To: Nathan Chancellor; +Cc: Kees Cook, Andrew Morton, LKML, clang-built-linux
On Tue, Jan 12, 2021 at 1:37 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> > if real_ptr is an unsigned long, do we want to use `__ffs(real_ptr) +
> > 1` here rather than ffs which takes an int? It seems the kernel is
> > missing a definition of ffsl. :(
>
> Why the + 1? I think if we use __ffs (which it seems like we should), I
> think that needs to become
This came up recently in an internal code review; ffs and __ffs differ
in output by one. See also the definition of ffs for alpha in
arch/alpha/include/asm/bitops.h.
Also, I just confirmed that:
```
#include <stdio.h>
// include/asm-generic/bitops/ffs.h
static inline int ffs(int x)
{
int r = 1;
if (!x)
return 0;
if (!(x & 0xffff)) {
x >>= 16;
r += 16;
}
if (!(x & 0xff)) {
x >>= 8;
r += 8;
}
if (!(x & 0xf)) {
x >>= 4;
r += 4;
}
if (!(x & 3)) {
x >>= 2;
r += 2;
}
if (!(x & 1)) {
x >>= 1;
r += 1;
}
return r;
}
// include/asm-generic/bitops/__ffs.h
static __always_inline unsigned long __ffs(unsigned long word)
{
int num = 0;
if ((word & 0xffffffff) == 0) {
num += 32;
word >>= 32;
}
if ((word & 0xffff) == 0) {
num += 16;
word >>= 16;
}
if ((word & 0xff) == 0) {
num += 8;
word >>= 8;
}
if ((word & 0xf) == 0) {
num += 4;
word >>= 4;
}
if ((word & 0x3) == 0) {
num += 2;
word >>= 2;
}
if ((word & 0x1) == 0)
num += 1;
return num;
}
int main() {
int x = 3;
unsigned long y = 3;
printf("%d\n%lu\n", ffs(x), __ffs(y));
return 0;
}
```
will print:
1
0
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-12 21:53 ` Nick Desaulniers
@ 2021-01-12 22:06 ` Nathan Chancellor
2021-01-12 23:56 ` Kees Cook
0 siblings, 1 reply; 14+ messages in thread
From: Nathan Chancellor @ 2021-01-12 22:06 UTC (permalink / raw)
To: Nick Desaulniers; +Cc: Kees Cook, Andrew Morton, LKML, clang-built-linux
On Tue, Jan 12, 2021 at 01:53:30PM -0800, Nick Desaulniers wrote:
> On Tue, Jan 12, 2021 at 1:37 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > > if real_ptr is an unsigned long, do we want to use `__ffs(real_ptr) +
> > > 1` here rather than ffs which takes an int? It seems the kernel is
> > > missing a definition of ffsl. :(
> >
> > Why the + 1? I think if we use __ffs (which it seems like we should), I
> > think that needs to become
>
> This came up recently in an internal code review; ffs and __ffs differ
> in output by one. See also the definition of ffs for alpha in
> arch/alpha/include/asm/bitops.h.
Interesting, thanks for bringing it up! Looks like ffs returns 1-32 and
__ffs returns 0-31. I think that we want __ffs here because we are
shifting (1UL << 32 overflows on 32-bit architectures) and the code in
LLVM appears to agree. LeastSignificantSetBitIndex evaluates to
__builtin_ctzl, which is the asm-generic implementation of __ffs.
Cheers,
NAthan
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-12 22:06 ` Nathan Chancellor
@ 2021-01-12 23:56 ` Kees Cook
0 siblings, 0 replies; 14+ messages in thread
From: Kees Cook @ 2021-01-12 23:56 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Nick Desaulniers, Andrew Morton, LKML, clang-built-linux
On Tue, Jan 12, 2021 at 03:06:34PM -0700, Nathan Chancellor wrote:
> On Tue, Jan 12, 2021 at 01:53:30PM -0800, Nick Desaulniers wrote:
> > On Tue, Jan 12, 2021 at 1:37 PM Nathan Chancellor
> > <natechancellor@gmail.com> wrote:
> > >
> > > > if real_ptr is an unsigned long, do we want to use `__ffs(real_ptr) +
> > > > 1` here rather than ffs which takes an int? It seems the kernel is
> > > > missing a definition of ffsl. :(
> > >
> > > Why the + 1? I think if we use __ffs (which it seems like we should), I
> > > think that needs to become
> >
> > This came up recently in an internal code review; ffs and __ffs differ
> > in output by one. See also the definition of ffs for alpha in
> > arch/alpha/include/asm/bitops.h.
>
> Interesting, thanks for bringing it up! Looks like ffs returns 1-32 and
> __ffs returns 0-31. I think that we want __ffs here because we are
> shifting (1UL << 32 overflows on 32-bit architectures) and the code in
> LLVM appears to agree. LeastSignificantSetBitIndex evaluates to
> __builtin_ctzl, which is the asm-generic implementation of __ffs.
Sounds good. With __ffs, consider your v2:
Acked-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-12 20:55 [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption Nathan Chancellor
2021-01-12 21:15 ` Nick Desaulniers
@ 2021-01-13 0:12 ` Nathan Chancellor
2021-01-27 22:44 ` [PATCH v3] " Nathan Chancellor
2021-01-13 0:18 ` [PATCH] " kernel test robot
2021-01-13 0:39 ` kernel test robot
3 siblings, 1 reply; 14+ messages in thread
From: Nathan Chancellor @ 2021-01-13 0:12 UTC (permalink / raw)
To: Andrew Morton
Cc: Kees Cook, Nick Desaulniers, linux-kernel, clang-built-linux,
Nathan Chancellor
When building ARCH=mips 32r2el_defconfig with CONFIG_UBSAN_ALIGNMENT:
ld.lld: error: undefined symbol: __ubsan_handle_alignment_assumption
>>> referenced by slab.h:557 (include/linux/slab.h:557)
>>> main.o:(do_initcalls) in archive init/built-in.a
>>> referenced by slab.h:448 (include/linux/slab.h:448)
>>> do_mounts_rd.o:(rd_load_image) in archive init/built-in.a
>>> referenced by slab.h:448 (include/linux/slab.h:448)
>>> do_mounts_rd.o:(identify_ramdisk_image) in archive init/built-in.a
>>> referenced 1579 more times
Implement this for the kernel based on LLVM's
handleAlignmentAssumptionImpl because the kernel is not linked against
the compiler runtime.
Link: https://github.com/ClangBuiltLinux/linux/issues/1245
Link: https://github.com/llvm/llvm-project/blob/llvmorg-11.0.1/compiler-rt/lib/ubsan/ubsan_handlers.cpp#L151-L190
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
v1 -> v2:
* Use __ffs instead of ffs because due to size of input (unsigned long
vs int) and we want a zero based index (Nick Desaulniers).
* Pick up Kees's ack.
lib/ubsan.c | 28 ++++++++++++++++++++++++++++
lib/ubsan.h | 6 ++++++
2 files changed, 34 insertions(+)
diff --git a/lib/ubsan.c b/lib/ubsan.c
index 3e3352f3d0da..1432a8645224 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -427,3 +427,31 @@ void __ubsan_handle_load_invalid_value(void *_data, void *val)
ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
+
+void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
+ unsigned long align,
+ unsigned long offset)
+{
+ struct alignment_assumption_data *data = _data;
+ unsigned long real_ptr;
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, "alignment-assumption");
+
+ if (offset)
+ pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed",
+ align, offset, data->type->type_name);
+ else
+ pr_err("assumption of %lu byte alignment for pointer of type %s failed",
+ align, data->type->type_name);
+
+ real_ptr = ptr - offset;
+ pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes",
+ offset ? "offset " : "", BIT(real_ptr ? __ffs(real_ptr) : 0),
+ real_ptr & (align - 1));
+
+ ubsan_epilogue();
+}
+EXPORT_SYMBOL(__ubsan_handle_alignment_assumption);
diff --git a/lib/ubsan.h b/lib/ubsan.h
index 7b56c09473a9..9a0b71c5ff9f 100644
--- a/lib/ubsan.h
+++ b/lib/ubsan.h
@@ -78,6 +78,12 @@ struct invalid_value_data {
struct type_descriptor *type;
};
+struct alignment_assumption_data {
+ struct source_location location;
+ struct source_location assumption_location;
+ struct type_descriptor *type;
+};
+
#if defined(CONFIG_ARCH_SUPPORTS_INT128)
typedef __int128 s_max;
typedef unsigned __int128 u_max;
base-commit: 7c53f6b671f4aba70ff15e1b05148b10d58c2837
--
2.30.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-13 0:12 ` [PATCH v2] " Nathan Chancellor
@ 2021-01-27 22:44 ` Nathan Chancellor
2021-01-27 22:54 ` Nick Desaulniers
0 siblings, 1 reply; 14+ messages in thread
From: Nathan Chancellor @ 2021-01-27 22:44 UTC (permalink / raw)
To: Andrew Morton
Cc: Kees Cook, Nick Desaulniers, linux-kernel, clang-built-linux,
Nathan Chancellor
When building ARCH=mips 32r2el_defconfig with CONFIG_UBSAN_ALIGNMENT:
ld.lld: error: undefined symbol: __ubsan_handle_alignment_assumption
>>> referenced by slab.h:557 (include/linux/slab.h:557)
>>> main.o:(do_initcalls) in archive init/built-in.a
>>> referenced by slab.h:448 (include/linux/slab.h:448)
>>> do_mounts_rd.o:(rd_load_image) in archive init/built-in.a
>>> referenced by slab.h:448 (include/linux/slab.h:448)
>>> do_mounts_rd.o:(identify_ramdisk_image) in archive init/built-in.a
>>> referenced 1579 more times
Implement this for the kernel based on LLVM's
handleAlignmentAssumptionImpl because the kernel is not linked against
the compiler runtime.
Link: https://github.com/ClangBuiltLinux/linux/issues/1245
Link: https://github.com/llvm/llvm-project/blob/llvmorg-11.0.1/compiler-rt/lib/ubsan/ubsan_handlers.cpp#L151-L190
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
v2 -> v3:
* Add prototype right above definition to avoid introducing a warning
with W=1.
v1 -> v2:
* Use __ffs instead of ffs because due to size of input (unsigned long
vs int) and we want a zero based index (Nick Desaulniers).
* Pick up Kees's ack.
lib/ubsan.c | 31 +++++++++++++++++++++++++++++++
lib/ubsan.h | 6 ++++++
2 files changed, 37 insertions(+)
diff --git a/lib/ubsan.c b/lib/ubsan.c
index 3e3352f3d0da..bec38c64d6a6 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -427,3 +427,34 @@ void __ubsan_handle_load_invalid_value(void *_data, void *val)
ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
+
+void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
+ unsigned long align,
+ unsigned long offset);
+void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
+ unsigned long align,
+ unsigned long offset)
+{
+ struct alignment_assumption_data *data = _data;
+ unsigned long real_ptr;
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, "alignment-assumption");
+
+ if (offset)
+ pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed",
+ align, offset, data->type->type_name);
+ else
+ pr_err("assumption of %lu byte alignment for pointer of type %s failed",
+ align, data->type->type_name);
+
+ real_ptr = ptr - offset;
+ pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes",
+ offset ? "offset " : "", BIT(real_ptr ? __ffs(real_ptr) : 0),
+ real_ptr & (align - 1));
+
+ ubsan_epilogue();
+}
+EXPORT_SYMBOL(__ubsan_handle_alignment_assumption);
diff --git a/lib/ubsan.h b/lib/ubsan.h
index 7b56c09473a9..9a0b71c5ff9f 100644
--- a/lib/ubsan.h
+++ b/lib/ubsan.h
@@ -78,6 +78,12 @@ struct invalid_value_data {
struct type_descriptor *type;
};
+struct alignment_assumption_data {
+ struct source_location location;
+ struct source_location assumption_location;
+ struct type_descriptor *type;
+};
+
#if defined(CONFIG_ARCH_SUPPORTS_INT128)
typedef __int128 s_max;
typedef unsigned __int128 u_max;
base-commit: 6ee1d745b7c9fd573fba142a2efdad76a9f1cb04
--
2.30.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v3] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-27 22:44 ` [PATCH v3] " Nathan Chancellor
@ 2021-01-27 22:54 ` Nick Desaulniers
0 siblings, 0 replies; 14+ messages in thread
From: Nick Desaulniers @ 2021-01-27 22:54 UTC (permalink / raw)
To: Nathan Chancellor, Andrew Morton; +Cc: Kees Cook, LKML, clang-built-linux
On Wed, Jan 27, 2021 at 2:46 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> When building ARCH=mips 32r2el_defconfig with CONFIG_UBSAN_ALIGNMENT:
>
> ld.lld: error: undefined symbol: __ubsan_handle_alignment_assumption
> >>> referenced by slab.h:557 (include/linux/slab.h:557)
> >>> main.o:(do_initcalls) in archive init/built-in.a
> >>> referenced by slab.h:448 (include/linux/slab.h:448)
> >>> do_mounts_rd.o:(rd_load_image) in archive init/built-in.a
> >>> referenced by slab.h:448 (include/linux/slab.h:448)
> >>> do_mounts_rd.o:(identify_ramdisk_image) in archive init/built-in.a
> >>> referenced 1579 more times
>
> Implement this for the kernel based on LLVM's
> handleAlignmentAssumptionImpl because the kernel is not linked against
> the compiler runtime.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1245
> Link: https://github.com/llvm/llvm-project/blob/llvmorg-11.0.1/compiler-rt/lib/ubsan/ubsan_handlers.cpp#L151-L190
> Acked-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>
> v2 -> v3:
>
> * Add prototype right above definition to avoid introducing a warning
> with W=1.
>
> v1 -> v2:
>
> * Use __ffs instead of ffs because due to size of input (unsigned long
> vs int) and we want a zero based index (Nick Desaulniers).
>
> * Pick up Kees's ack.
>
> lib/ubsan.c | 31 +++++++++++++++++++++++++++++++
> lib/ubsan.h | 6 ++++++
> 2 files changed, 37 insertions(+)
>
> diff --git a/lib/ubsan.c b/lib/ubsan.c
> index 3e3352f3d0da..bec38c64d6a6 100644
> --- a/lib/ubsan.c
> +++ b/lib/ubsan.c
> @@ -427,3 +427,34 @@ void __ubsan_handle_load_invalid_value(void *_data, void *val)
> ubsan_epilogue();
> }
> EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
> +
> +void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
> + unsigned long align,
> + unsigned long offset);
> +void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
> + unsigned long align,
> + unsigned long offset)
> +{
> + struct alignment_assumption_data *data = _data;
> + unsigned long real_ptr;
> +
> + if (suppress_report(&data->location))
> + return;
> +
> + ubsan_prologue(&data->location, "alignment-assumption");
> +
> + if (offset)
> + pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed",
> + align, offset, data->type->type_name);
> + else
> + pr_err("assumption of %lu byte alignment for pointer of type %s failed",
> + align, data->type->type_name);
> +
> + real_ptr = ptr - offset;
> + pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes",
> + offset ? "offset " : "", BIT(real_ptr ? __ffs(real_ptr) : 0),
> + real_ptr & (align - 1));
> +
> + ubsan_epilogue();
> +}
> +EXPORT_SYMBOL(__ubsan_handle_alignment_assumption);
> diff --git a/lib/ubsan.h b/lib/ubsan.h
> index 7b56c09473a9..9a0b71c5ff9f 100644
> --- a/lib/ubsan.h
> +++ b/lib/ubsan.h
> @@ -78,6 +78,12 @@ struct invalid_value_data {
> struct type_descriptor *type;
> };
>
> +struct alignment_assumption_data {
> + struct source_location location;
> + struct source_location assumption_location;
> + struct type_descriptor *type;
> +};
> +
> #if defined(CONFIG_ARCH_SUPPORTS_INT128)
> typedef __int128 s_max;
> typedef unsigned __int128 u_max;
>
> base-commit: 6ee1d745b7c9fd573fba142a2efdad76a9f1cb04
> --
> 2.30.0
>
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-12 20:55 [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption Nathan Chancellor
2021-01-12 21:15 ` Nick Desaulniers
2021-01-13 0:12 ` [PATCH v2] " Nathan Chancellor
@ 2021-01-13 0:18 ` kernel test robot
2021-01-13 0:39 ` kernel test robot
3 siblings, 0 replies; 14+ messages in thread
From: kernel test robot @ 2021-01-13 0:18 UTC (permalink / raw)
To: Nathan Chancellor, Kees Cook, Andrew Morton
Cc: kbuild-all, Linux Memory Management List, Nick Desaulniers,
linux-kernel, clang-built-linux, Nathan Chancellor
[-- Attachment #1: Type: text/plain, Size: 6745 bytes --]
Hi Nathan,
I love your patch! Perhaps something to improve:
[auto build test WARNING on 7c53f6b671f4aba70ff15e1b05148b10d58c2837]
url: https://github.com/0day-ci/linux/commits/Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
base: 7c53f6b671f4aba70ff15e1b05148b10d58c2837
config: m68k-allmodconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/775adad26a60878926c0ee6cd460a1375bbe51e6
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
git checkout 775adad26a60878926c0ee6cd460a1375bbe51e6
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
lib/ubsan.c:192:6: warning: no previous prototype for '__ubsan_handle_add_overflow' [-Wmissing-prototypes]
192 | void __ubsan_handle_add_overflow(void *data,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:200:6: warning: no previous prototype for '__ubsan_handle_sub_overflow' [-Wmissing-prototypes]
200 | void __ubsan_handle_sub_overflow(void *data,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:207:6: warning: no previous prototype for '__ubsan_handle_mul_overflow' [-Wmissing-prototypes]
207 | void __ubsan_handle_mul_overflow(void *data,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:214:6: warning: no previous prototype for '__ubsan_handle_negate_overflow' [-Wmissing-prototypes]
214 | void __ubsan_handle_negate_overflow(void *_data, void *old_val)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:234:6: warning: no previous prototype for '__ubsan_handle_divrem_overflow' [-Wmissing-prototypes]
234 | void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:315:6: warning: no previous prototype for '__ubsan_handle_type_mismatch' [-Wmissing-prototypes]
315 | void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:329:6: warning: no previous prototype for '__ubsan_handle_type_mismatch_v1' [-Wmissing-prototypes]
329 | void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:343:6: warning: no previous prototype for '__ubsan_handle_out_of_bounds' [-Wmissing-prototypes]
343 | void __ubsan_handle_out_of_bounds(void *_data, void *index)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:360:6: warning: no previous prototype for '__ubsan_handle_shift_out_of_bounds' [-Wmissing-prototypes]
360 | void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:402:6: warning: no previous prototype for '__ubsan_handle_builtin_unreachable' [-Wmissing-prototypes]
402 | void __ubsan_handle_builtin_unreachable(void *_data)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/ubsan.c:412:6: warning: no previous prototype for '__ubsan_handle_load_invalid_value' [-Wmissing-prototypes]
412 | void __ubsan_handle_load_invalid_value(void *_data, void *val)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> lib/ubsan.c:431:6: warning: no previous prototype for '__ubsan_handle_alignment_assumption' [-Wmissing-prototypes]
431 | void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/__ubsan_handle_alignment_assumption +431 lib/ubsan.c
359
> 360 void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs)
361 {
362 struct shift_out_of_bounds_data *data = _data;
363 struct type_descriptor *rhs_type = data->rhs_type;
364 struct type_descriptor *lhs_type = data->lhs_type;
365 char rhs_str[VALUE_LENGTH];
366 char lhs_str[VALUE_LENGTH];
367 unsigned long ua_flags = user_access_save();
368
369 if (suppress_report(&data->location))
370 goto out;
371
372 ubsan_prologue(&data->location, "shift-out-of-bounds");
373
374 val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
375 val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
376
377 if (val_is_negative(rhs_type, rhs))
378 pr_err("shift exponent %s is negative\n", rhs_str);
379
380 else if (get_unsigned_val(rhs_type, rhs) >=
381 type_bit_width(lhs_type))
382 pr_err("shift exponent %s is too large for %u-bit type %s\n",
383 rhs_str,
384 type_bit_width(lhs_type),
385 lhs_type->type_name);
386 else if (val_is_negative(lhs_type, lhs))
387 pr_err("left shift of negative value %s\n",
388 lhs_str);
389 else
390 pr_err("left shift of %s by %s places cannot be"
391 " represented in type %s\n",
392 lhs_str, rhs_str,
393 lhs_type->type_name);
394
395 ubsan_epilogue();
396 out:
397 user_access_restore(ua_flags);
398 }
399 EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
400
401
402 void __ubsan_handle_builtin_unreachable(void *_data)
403 {
404 struct unreachable_data *data = _data;
405 ubsan_prologue(&data->location, "unreachable");
406 pr_err("calling __builtin_unreachable()\n");
407 ubsan_epilogue();
408 panic("can't return from __builtin_unreachable()");
409 }
410 EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
411
412 void __ubsan_handle_load_invalid_value(void *_data, void *val)
413 {
414 struct invalid_value_data *data = _data;
415 char val_str[VALUE_LENGTH];
416
417 if (suppress_report(&data->location))
418 return;
419
420 ubsan_prologue(&data->location, "invalid-load");
421
422 val_to_string(val_str, sizeof(val_str), data->type, val);
423
424 pr_err("load of value %s is not a valid value for type %s\n",
425 val_str, data->type->type_name);
426
427 ubsan_epilogue();
428 }
429 EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
430
> 431 void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 59573 bytes --]
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-12 20:55 [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption Nathan Chancellor
` (2 preceding siblings ...)
2021-01-13 0:18 ` [PATCH] " kernel test robot
@ 2021-01-13 0:39 ` kernel test robot
2021-01-13 1:31 ` Nathan Chancellor
3 siblings, 1 reply; 14+ messages in thread
From: kernel test robot @ 2021-01-13 0:39 UTC (permalink / raw)
To: Nathan Chancellor, Kees Cook, Andrew Morton
Cc: kbuild-all, clang-built-linux, Linux Memory Management List,
Nick Desaulniers, linux-kernel, Nathan Chancellor
[-- Attachment #1: Type: text/plain, Size: 7053 bytes --]
Hi Nathan,
I love your patch! Perhaps something to improve:
[auto build test WARNING on 7c53f6b671f4aba70ff15e1b05148b10d58c2837]
url: https://github.com/0day-ci/linux/commits/Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
base: 7c53f6b671f4aba70ff15e1b05148b10d58c2837
config: arm64-randconfig-r031-20210112 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 32bcfcda4e28375e5a85268d2acfabcfcc011abf)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/0day-ci/linux/commit/775adad26a60878926c0ee6cd460a1375bbe51e6
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
git checkout 775adad26a60878926c0ee6cd460a1375bbe51e6
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
lib/ubsan.c:192:6: warning: no previous prototype for function '__ubsan_handle_add_overflow' [-Wmissing-prototypes]
void __ubsan_handle_add_overflow(void *data,
^
lib/ubsan.c:192:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_add_overflow(void *data,
^
static
lib/ubsan.c:200:6: warning: no previous prototype for function '__ubsan_handle_sub_overflow' [-Wmissing-prototypes]
void __ubsan_handle_sub_overflow(void *data,
^
lib/ubsan.c:200:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_sub_overflow(void *data,
^
static
lib/ubsan.c:207:6: warning: no previous prototype for function '__ubsan_handle_mul_overflow' [-Wmissing-prototypes]
void __ubsan_handle_mul_overflow(void *data,
^
lib/ubsan.c:207:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_mul_overflow(void *data,
^
static
lib/ubsan.c:214:6: warning: no previous prototype for function '__ubsan_handle_negate_overflow' [-Wmissing-prototypes]
void __ubsan_handle_negate_overflow(void *_data, void *old_val)
^
lib/ubsan.c:214:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_negate_overflow(void *_data, void *old_val)
^
static
lib/ubsan.c:234:6: warning: no previous prototype for function '__ubsan_handle_divrem_overflow' [-Wmissing-prototypes]
void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs)
^
lib/ubsan.c:234:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs)
^
static
lib/ubsan.c:315:6: warning: no previous prototype for function '__ubsan_handle_type_mismatch' [-Wmissing-prototypes]
void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
^
lib/ubsan.c:315:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
^
static
lib/ubsan.c:329:6: warning: no previous prototype for function '__ubsan_handle_type_mismatch_v1' [-Wmissing-prototypes]
void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr)
^
lib/ubsan.c:329:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr)
^
static
lib/ubsan.c:343:6: warning: no previous prototype for function '__ubsan_handle_out_of_bounds' [-Wmissing-prototypes]
void __ubsan_handle_out_of_bounds(void *_data, void *index)
^
lib/ubsan.c:343:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_out_of_bounds(void *_data, void *index)
^
static
lib/ubsan.c:360:6: warning: no previous prototype for function '__ubsan_handle_shift_out_of_bounds' [-Wmissing-prototypes]
void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs)
^
lib/ubsan.c:360:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs)
^
static
lib/ubsan.c:402:6: warning: no previous prototype for function '__ubsan_handle_builtin_unreachable' [-Wmissing-prototypes]
void __ubsan_handle_builtin_unreachable(void *_data)
^
lib/ubsan.c:402:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_builtin_unreachable(void *_data)
^
static
lib/ubsan.c:412:6: warning: no previous prototype for function '__ubsan_handle_load_invalid_value' [-Wmissing-prototypes]
void __ubsan_handle_load_invalid_value(void *_data, void *val)
^
lib/ubsan.c:412:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_load_invalid_value(void *_data, void *val)
^
static
>> lib/ubsan.c:431:6: warning: no previous prototype for function '__ubsan_handle_alignment_assumption' [-Wmissing-prototypes]
void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
^
lib/ubsan.c:431:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
^
static
12 warnings generated.
vim +/__ubsan_handle_alignment_assumption +431 lib/ubsan.c
411
> 412 void __ubsan_handle_load_invalid_value(void *_data, void *val)
413 {
414 struct invalid_value_data *data = _data;
415 char val_str[VALUE_LENGTH];
416
417 if (suppress_report(&data->location))
418 return;
419
420 ubsan_prologue(&data->location, "invalid-load");
421
422 val_to_string(val_str, sizeof(val_str), data->type, val);
423
424 pr_err("load of value %s is not a valid value for type %s\n",
425 val_str, data->type->type_name);
426
427 ubsan_epilogue();
428 }
429 EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
430
> 431 void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 31723 bytes --]
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-13 0:39 ` kernel test robot
@ 2021-01-13 1:31 ` Nathan Chancellor
2021-01-13 1:39 ` Nick Desaulniers
0 siblings, 1 reply; 14+ messages in thread
From: Nathan Chancellor @ 2021-01-13 1:31 UTC (permalink / raw)
To: kernel test robot
Cc: Kees Cook, Andrew Morton, kbuild-all, clang-built-linux,
Linux Memory Management List, Nick Desaulniers, linux-kernel
On Wed, Jan 13, 2021 at 08:39:52AM +0800, kernel test robot wrote:
> Hi Nathan,
>
> I love your patch! Perhaps something to improve:
>
> [auto build test WARNING on 7c53f6b671f4aba70ff15e1b05148b10d58c2837]
>
> url: https://github.com/0day-ci/linux/commits/Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
> base: 7c53f6b671f4aba70ff15e1b05148b10d58c2837
> config: arm64-randconfig-r031-20210112 (attached as .config)
> compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 32bcfcda4e28375e5a85268d2acfabcfcc011abf)
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # install arm64 cross compiling tool for clang build
> # apt-get install binutils-aarch64-linux-gnu
> # https://github.com/0day-ci/linux/commit/775adad26a60878926c0ee6cd460a1375bbe51e6
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
> git checkout 775adad26a60878926c0ee6cd460a1375bbe51e6
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> lib/ubsan.c:192:6: warning: no previous prototype for function '__ubsan_handle_add_overflow' [-Wmissing-prototypes]
> void __ubsan_handle_add_overflow(void *data,
> ^
> lib/ubsan.c:192:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> void __ubsan_handle_add_overflow(void *data,
> ^
> static
> lib/ubsan.c:200:6: warning: no previous prototype for function '__ubsan_handle_sub_overflow' [-Wmissing-prototypes]
> void __ubsan_handle_sub_overflow(void *data,
> ^
> lib/ubsan.c:200:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> void __ubsan_handle_sub_overflow(void *data,
> ^
Given that these are compiler inserted functions, there is not much of a
point to having prototypes to them. If people feel shutting these
warnings up is worthwhile, we can just add the prototypes right above
the function definition in a follow up patch.
Cheers,
Nathan
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-13 1:31 ` Nathan Chancellor
@ 2021-01-13 1:39 ` Nick Desaulniers
2021-01-27 22:26 ` Nick Desaulniers
0 siblings, 1 reply; 14+ messages in thread
From: Nick Desaulniers @ 2021-01-13 1:39 UTC (permalink / raw)
To: Nathan Chancellor
Cc: kernel test robot, Kees Cook, Andrew Morton, kbuild-all,
clang-built-linux, Linux Memory Management List, LKML
On Tue, Jan 12, 2021 at 5:31 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Wed, Jan 13, 2021 at 08:39:52AM +0800, kernel test robot wrote:
> > Hi Nathan,
> >
> > I love your patch! Perhaps something to improve:
> >
> > [auto build test WARNING on 7c53f6b671f4aba70ff15e1b05148b10d58c2837]
> >
> > url: https://github.com/0day-ci/linux/commits/Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
> > base: 7c53f6b671f4aba70ff15e1b05148b10d58c2837
> > config: arm64-randconfig-r031-20210112 (attached as .config)
> > compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 32bcfcda4e28375e5a85268d2acfabcfcc011abf)
> > reproduce (this is a W=1 build):
> > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > # install arm64 cross compiling tool for clang build
> > # apt-get install binutils-aarch64-linux-gnu
> > # https://github.com/0day-ci/linux/commit/775adad26a60878926c0ee6cd460a1375bbe51e6
> > git remote add linux-review https://github.com/0day-ci/linux
> > git fetch --no-tags linux-review Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
> > git checkout 775adad26a60878926c0ee6cd460a1375bbe51e6
> > # save the attached .config to linux build tree
> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All warnings (new ones prefixed by >>):
> >
> > lib/ubsan.c:192:6: warning: no previous prototype for function '__ubsan_handle_add_overflow' [-Wmissing-prototypes]
> > void __ubsan_handle_add_overflow(void *data,
> > ^
> > lib/ubsan.c:192:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> > void __ubsan_handle_add_overflow(void *data,
> > ^
> > static
> > lib/ubsan.c:200:6: warning: no previous prototype for function '__ubsan_handle_sub_overflow' [-Wmissing-prototypes]
> > void __ubsan_handle_sub_overflow(void *data,
> > ^
> > lib/ubsan.c:200:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> > void __ubsan_handle_sub_overflow(void *data,
> > ^
>
> Given that these are compiler inserted functions, there is not much of a
> point to having prototypes to them. If people feel shutting these
> warnings up is worthwhile, we can just add the prototypes right above
> the function definition in a follow up patch.
Same as stpcpy; it would be nice though. ;)
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] ubsan: Implement __ubsan_handle_alignment_assumption
2021-01-13 1:39 ` Nick Desaulniers
@ 2021-01-27 22:26 ` Nick Desaulniers
0 siblings, 0 replies; 14+ messages in thread
From: Nick Desaulniers @ 2021-01-27 22:26 UTC (permalink / raw)
To: Nathan Chancellor
Cc: kernel test robot, Kees Cook, Andrew Morton, kbuild-all,
clang-built-linux, Linux Memory Management List, LKML
On Tue, Jan 12, 2021 at 5:39 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Tue, Jan 12, 2021 at 5:31 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > On Wed, Jan 13, 2021 at 08:39:52AM +0800, kernel test robot wrote:
> > > Hi Nathan,
> > >
> > > I love your patch! Perhaps something to improve:
> > >
> > > [auto build test WARNING on 7c53f6b671f4aba70ff15e1b05148b10d58c2837]
> > >
> > > url: https://github.com/0day-ci/linux/commits/Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
> > > base: 7c53f6b671f4aba70ff15e1b05148b10d58c2837
> > > config: arm64-randconfig-r031-20210112 (attached as .config)
> > > compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 32bcfcda4e28375e5a85268d2acfabcfcc011abf)
> > > reproduce (this is a W=1 build):
> > > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > > chmod +x ~/bin/make.cross
> > > # install arm64 cross compiling tool for clang build
> > > # apt-get install binutils-aarch64-linux-gnu
> > > # https://github.com/0day-ci/linux/commit/775adad26a60878926c0ee6cd460a1375bbe51e6
> > > git remote add linux-review https://github.com/0day-ci/linux
> > > git fetch --no-tags linux-review Nathan-Chancellor/ubsan-Implement-__ubsan_handle_alignment_assumption/20210113-055714
> > > git checkout 775adad26a60878926c0ee6cd460a1375bbe51e6
> > > # save the attached .config to linux build tree
> > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
> > >
> > > If you fix the issue, kindly add following tag as appropriate
> > > Reported-by: kernel test robot <lkp@intel.com>
> > >
> > > All warnings (new ones prefixed by >>):
> > >
> > > lib/ubsan.c:192:6: warning: no previous prototype for function '__ubsan_handle_add_overflow' [-Wmissing-prototypes]
> > > void __ubsan_handle_add_overflow(void *data,
> > > ^
> > > lib/ubsan.c:192:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> > > void __ubsan_handle_add_overflow(void *data,
> > > ^
> > > static
> > > lib/ubsan.c:200:6: warning: no previous prototype for function '__ubsan_handle_sub_overflow' [-Wmissing-prototypes]
> > > void __ubsan_handle_sub_overflow(void *data,
> > > ^
> > > lib/ubsan.c:200:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> > > void __ubsan_handle_sub_overflow(void *data,
> > > ^
> >
> > Given that these are compiler inserted functions, there is not much of a
> > point to having prototypes to them. If people feel shutting these
> > warnings up is worthwhile, we can just add the prototypes right above
> > the function definition in a follow up patch.
>
> Same as stpcpy; it would be nice though. ;)
If you would be so kind, I'd be happy to sign off on such a v3.
> --
> Thanks,
> ~Nick Desaulniers
--
Thanks,
~Nick Desaulniers
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