Commit 2d6261583be0 ("lib: rework bitmap_parse()") does
not take into account order of halfwords on 64-bit big
endian architectures.
Fixes: 2d6261583be0 ("lib: rework bitmap_parse()")
Cc: [email protected]
Cc: Yury Norov <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Amritha Nambiar <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miklos Szeredi <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Steffen Klassert <[email protected]>
Cc: "Tobin C . Harding" <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Willem de Bruijn <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>
---
lib/bitmap.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 89260aa..a725e46 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -717,6 +717,19 @@ static const char *bitmap_get_x32_reverse(const char *start,
return end;
}
+#if defined(__BIG_ENDIAN) && defined(CONFIG_64BIT)
+static void save_x32_chunk(unsigned long *maskp, u32 chunk, int chunk_idx)
+{
+ maskp += (chunk_idx / 2);
+ ((u32 *)maskp)[(chunk_idx & 1) ^ 1] = chunk;
+}
+#else
+static void save_x32_chunk(unsigned long *maskp, u32 chunk, int chunk_idx)
+{
+ ((u32 *)maskp)[chunk_idx] = chunk;
+}
+#endif
+
/**
* bitmap_parse - convert an ASCII hex string into a bitmap.
* @start: pointer to buffer containing string.
@@ -738,7 +751,8 @@ int bitmap_parse(const char *start, unsigned int buflen,
{
const char *end = strnchrnul(start, buflen, '\n') - 1;
int chunks = BITS_TO_U32(nmaskbits);
- u32 *bitmap = (u32 *)maskp;
+ int chunk_idx = 0;
+ u32 chunk;
int unset_bit;
while (1) {
@@ -749,9 +763,11 @@ int bitmap_parse(const char *start, unsigned int buflen,
if (!chunks--)
return -EOVERFLOW;
- end = bitmap_get_x32_reverse(start, end, bitmap++);
+ end = bitmap_get_x32_reverse(start, end, &chunk);
if (IS_ERR(end))
return PTR_ERR(end);
+
+ save_x32_chunk(maskp, chunk, chunk_idx++);
}
unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32;
--
1.8.3.1
On Mon, May 18, 2020 at 1:40 PM Alexander Gordeev
<[email protected]> wrote:
>
> Commit 2d6261583be0 ("lib: rework bitmap_parse()") does
> not take into account order of halfwords on 64-bit big
> endian architectures.
Thanks for report and the patch!
Did it work before? Can we have a test case for that that we will see
the failure?
> Fixes: 2d6261583be0 ("lib: rework bitmap_parse()")
> Cc: [email protected]
> Cc: Yury Norov <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Cc: Amritha Nambiar <[email protected]>
> Cc: Arnaldo Carvalho de Melo <[email protected]>
> Cc: Chris Wilson <[email protected]>
> Cc: Kees Cook <[email protected]>
> Cc: Matthew Wilcox <[email protected]>
> Cc: Miklos Szeredi <[email protected]>
> Cc: Rasmus Villemoes <[email protected]>
> Cc: Steffen Klassert <[email protected]>
> Cc: "Tobin C . Harding" <[email protected]>
> Cc: Vineet Gupta <[email protected]>
> Cc: Will Deacon <[email protected]>
> Cc: Willem de Bruijn <[email protected]>
> Signed-off-by: Alexander Gordeev <[email protected]>
> ---
> lib/bitmap.c | 20 ++++++++++++++++++--
> 1 file changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/lib/bitmap.c b/lib/bitmap.c
> index 89260aa..a725e46 100644
> --- a/lib/bitmap.c
> +++ b/lib/bitmap.c
> @@ -717,6 +717,19 @@ static const char *bitmap_get_x32_reverse(const char *start,
> return end;
> }
>
> +#if defined(__BIG_ENDIAN) && defined(CONFIG_64BIT)
> +static void save_x32_chunk(unsigned long *maskp, u32 chunk, int chunk_idx)
> +{
> + maskp += (chunk_idx / 2);
> + ((u32 *)maskp)[(chunk_idx & 1) ^ 1] = chunk;
> +}
> +#else
> +static void save_x32_chunk(unsigned long *maskp, u32 chunk, int chunk_idx)
> +{
> + ((u32 *)maskp)[chunk_idx] = chunk;
> +}
> +#endif
> +
> /**
> * bitmap_parse - convert an ASCII hex string into a bitmap.
> * @start: pointer to buffer containing string.
> @@ -738,7 +751,8 @@ int bitmap_parse(const char *start, unsigned int buflen,
> {
> const char *end = strnchrnul(start, buflen, '\n') - 1;
> int chunks = BITS_TO_U32(nmaskbits);
> - u32 *bitmap = (u32 *)maskp;
> + int chunk_idx = 0;
> + u32 chunk;
> int unset_bit;
>
> while (1) {
> @@ -749,9 +763,11 @@ int bitmap_parse(const char *start, unsigned int buflen,
> if (!chunks--)
> return -EOVERFLOW;
>
> - end = bitmap_get_x32_reverse(start, end, bitmap++);
> + end = bitmap_get_x32_reverse(start, end, &chunk);
> if (IS_ERR(end))
> return PTR_ERR(end);
> +
> + save_x32_chunk(maskp, chunk, chunk_idx++);
> }
>
> unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32;
> --
> 1.8.3.1
>
--
With Best Regards,
Andy Shevchenko
On Mon, May 18, 2020 at 2:33 PM Andy Shevchenko
<[email protected]> wrote:
>
> On Mon, May 18, 2020 at 1:40 PM Alexander Gordeev
> <[email protected]> wrote:
> >
> > Commit 2d6261583be0 ("lib: rework bitmap_parse()") does
> > not take into account order of halfwords on 64-bit big
> > endian architectures.
>
> Thanks for report and the patch!
>
> Did it work before? Can we have a test case for that that we will see
> the failure?
Sorry, I wasn't clear enough. I meant a test case that is
arch-independent for this very issue (so, that I can run it on LE 64
machine and see a problem).
--
With Best Regards,
Andy Shevchenko
On Mon, May 18, 2020 at 02:33:43PM +0300, Andy Shevchenko wrote:
> On Mon, May 18, 2020 at 1:40 PM Alexander Gordeev
> <[email protected]> wrote:
> >
> > Commit 2d6261583be0 ("lib: rework bitmap_parse()") does
> > not take into account order of halfwords on 64-bit big
> > endian architectures.
>
> Thanks for report and the patch!
>
> Did it work before? Can we have a test case for that that we will see
> the failure?
The test exists and enabled with CONFIG_TEST_BITMAP.
It does not appear ever passed before on 64 BE.
It does not fail on 64 LE for me either.
Thanks!
[...]
> --
> With Best Regards,
> Andy Shevchenko
On Mon, May 18, 2020 at 01:50:59PM +0200, Alexander Gordeev wrote:
> On Mon, May 18, 2020 at 02:33:43PM +0300, Andy Shevchenko wrote:
> > On Mon, May 18, 2020 at 1:40 PM Alexander Gordeev
> > <[email protected]> wrote:
> > >
> > > Commit 2d6261583be0 ("lib: rework bitmap_parse()") does
> > > not take into account order of halfwords on 64-bit big
> > > endian architectures.
> >
> > Thanks for report and the patch!
> >
> > Did it work before? Can we have a test case for that that we will see
> > the failure?
>
> The test exists and enabled with CONFIG_TEST_BITMAP.
> It does not appear ever passed before on 64 BE.
> It does not fail on 64 LE for me either.
Hi Andy et al,
Any feedback on the fix? Does it work on 64 LE for you?
Thanks!
> Thanks!
>
> [...]
>
> > --
> > With Best Regards,
> > Andy Shevchenko
On Tue, Jun 02, 2020 at 12:24:31PM +0200, Alexander Gordeev wrote:
> On Mon, May 18, 2020 at 01:50:59PM +0200, Alexander Gordeev wrote:
> > On Mon, May 18, 2020 at 02:33:43PM +0300, Andy Shevchenko wrote:
> > > On Mon, May 18, 2020 at 1:40 PM Alexander Gordeev
> > > <[email protected]> wrote:
> > > >
> > > > Commit 2d6261583be0 ("lib: rework bitmap_parse()") does
> > > > not take into account order of halfwords on 64-bit big
> > > > endian architectures.
> > >
> > > Thanks for report and the patch!
> > >
> > > Did it work before? Can we have a test case for that that we will see
> > > the failure?
> >
> > The test exists and enabled with CONFIG_TEST_BITMAP.
> > It does not appear ever passed before on 64 BE.
> > It does not fail on 64 LE for me either.
>
> Hi Andy et al,
>
> Any feedback on the fix? Does it work on 64 LE for you?
Test case, please.
Yes, you can simulate BE test case on LE platform and vise versa.
--
With Best Regards,
Andy Shevchenko
On Fri, Jun 05, 2020 at 04:25:58PM +0300, Andy Shevchenko wrote:
> Test case, please.
Hi Andy,
Below is the output of the runtime kernel test "test_bitmap".
I resent the patch with Andrew Morton on CC, but did not include
the excessive test output:
test_bitmap: parse: 4: input is 1, result is 0x100000000, expected 0x1
test_bitmap: parse: 5: input is deadbeef, result is 0xdeadbeef00000000, expected 0xdeadbeef
test_bitmap: parse: 6: input is 1,0, result is 0x1, expected 0x100000000
test_bitmap: parse: 7: input is deadbeef,,0,1, result is 0x1, expected 0xdeadbeef
test_bitmap: parse: 8: input is deadbeef,1,0, result is 0x1, expected 0x100000000
test_bitmap: parse: 9: input is baadf00d,deadbeef,1,0, result is 0x1, expected 0x100000000
test_bitmap: parse: 10: input is badf00d,deadbeef,1,0, errno is -75, expected 0
test_bitmap: parse: 11: input is badf00d,deadbeef,1,0, errno is -75, expected 0
test_bitmap: parse: 12: input is badf00d,deadbeef,1,0 , errno is -75, expected 0
test_bitmap: parse: 13: input is , badf00d,deadbeef,1,0 , , errno is -75, expected 0
test_bitmap: parse: 14: input is , badf00d, ,, ,,deadbeef,1,0 , , errno is -75, expected 0
test_bitmap: parse: 16: input is 3,0, errno is 0, expected -75
test_bitmap: parse_user: 4: input is 1, result is 0x100000000, expected 0x1
test_bitmap: parse_user: 5: input is deadbeef, result is 0xdeadbeef00000000, expected 0xdeadbeef
test_bitmap: parse_user: 6: input is 1,0, result is 0x1, expected 0x100000000
test_bitmap: parse_user: 7: input is deadbeef,,0,1, result is 0x1, expected 0xdeadbeef
test_bitmap: parse_user: 8: input is deadbeef,1,0, result is 0x1, expected 0x100000000
test_bitmap: parse_user: 9: input is baadf00d,deadbeef,1,0, result is 0x1, expected 0x100000000
test_bitmap: parse_user: 10: input is badf00d,deadbeef,1,0, errno is -75, expected 0
test_bitmap: parse_user: 11: input is badf00d,deadbeef,1,0, errno is -75, expected 0
test_bitmap: parse_user: 12: input is badf00d,deadbeef,1,0 , errno is -75, expected 0
test_bitmap: parse_user: 13: input is , badf00d,deadbeef,1,0 , , errno is -75, expected 0
test_bitmap: parse_user: 14: input is , badf00d, ,, ,,deadbeef,1,0 , , errno is -75, expected 0
test_bitmap: parse_user: 16: input is 3,0, errno is 0, expected -75
Thanks!
> Yes, you can simulate BE test case on LE platform and vise versa.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>