hi, Andrew thanks for you kind reply :) On 2015年07月10日 06:57, Andrew Morton wrote: > On Sat, 27 Jun 2015 14:36:18 +0800 Pan Xinhui <xinhuix....@intel.com> wrote: > >> Sometimes the input from user may cause an unexpected result. >> >> for example, echo "1-3," > /proc/irq/<xxx>/smp_affinity_list. >> The correct result should be 1-3, however we got 0-4. >> >> To avoid this issue, we check if there is a ready digit. >> If no valid digit is set, we just continue to the next parse. >> >> Signed-off-by: Pan Xinhui <xinhuix....@intel.com> >> --- >> lib/bitmap.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/lib/bitmap.c b/lib/bitmap.c >> index 64c0926..3c489c1 100644 >> --- a/lib/bitmap.c >> +++ b/lib/bitmap.c >> @@ -561,6 +561,8 @@ static int __bitmap_parselist(const char *buf, unsigned >> int buflen, >> return -EINVAL; >> if (b >= nmaskbits) >> return -ERANGE; >> + if (unlikely(exp_digit)) >> + continue; >> while (a <= b) { >> set_bit(a, maskp); >> a++; > > This bug might have been fixed by 2528a8b8f457d7 ("__bitmap_parselist: > fix bug in empty string handling"), below. Please check? > > Yes, I noticed it after I sent this patch out. Sorry for not syncing the upstream codes. I am very happy that you reviewed my patch :)
I send out other three patches to make current codes stronger :) they are [PATCH 1/3] lib/bitmap.c: correct a code style and do some optimization in __bitmap_parse [PATCH 2/3] lib/bitmap.c: fix a special string handling bug in __bitmap_parselist [PATCH 3/3] lib/bitmap.c: bitmap_parselist can accept string with whitespaces on head or tail Of course I have verified/test them :) They have minor codes change. thanks xinhui > commit 2528a8b8f457d7432552d0e2b6f0f4046bb702f4 > Author: Chris Metcalf <cmetc...@ezchip.com> > AuthorDate: Thu Jun 25 15:02:08 2015 -0700 > Commit: Linus Torvalds <torva...@linux-foundation.org> > CommitDate: Thu Jun 25 17:00:40 2015 -0700 > > __bitmap_parselist: fix bug in empty string handling > > bitmap_parselist("", &mask, nmaskbits) will erroneously set bit zero in > the mask. The same bug is visible in cpumask_parselist() since it is > layered on top of the bitmask code, e.g. if you boot with "isolcpus=", > you will actually end up with cpu zero isolated. > > The bug was introduced in commit 4b060420a596 ("bitmap, irq: add > smp_affinity_list interface to /proc/irq") when bitmap_parselist() was > generalized to support userspace as well as kernelspace. > > Fixes: 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to > /proc/irq") > Signed-off-by: Chris Metcalf <cmetc...@ezchip.com> > Cc: Rasmus Villemoes <li...@rasmusvillemoes.dk> > Signed-off-by: Andrew Morton <a...@linux-foundation.org> > Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> > > diff --git a/lib/bitmap.c b/lib/bitmap.c > index 64c0926..40162f8 100644 > --- a/lib/bitmap.c > +++ b/lib/bitmap.c > @@ -506,12 +506,12 @@ static int __bitmap_parselist(const char *buf, unsigned > int buflen, > unsigned a, b; > int c, old_c, totaldigits; > const char __user __force *ubuf = (const char __user __force *)buf; > - int exp_digit, in_range; > + int at_start, in_range; > > totaldigits = c = 0; > bitmap_zero(maskp, nmaskbits); > do { > - exp_digit = 1; > + at_start = 1; > in_range = 0; > a = b = 0; > > @@ -540,11 +540,10 @@ static int __bitmap_parselist(const char *buf, unsigned > int buflen, > break; > > if (c == '-') { > - if (exp_digit || in_range) > + if (at_start || in_range) > return -EINVAL; > b = 0; > in_range = 1; > - exp_digit = 1; > continue; > } > > @@ -554,16 +553,18 @@ static int __bitmap_parselist(const char *buf, unsigned > int buflen, > b = b * 10 + (c - '0'); > if (!in_range) > a = b; > - exp_digit = 0; > + at_start = 0; > totaldigits++; > } > if (!(a <= b)) > return -EINVAL; > if (b >= nmaskbits) > return -ERANGE; > - while (a <= b) { > - set_bit(a, maskp); > - a++; > + if (!at_start) { > + while (a <= b) { > + set_bit(a, maskp); > + a++; > + } > } > } while (buflen && c == ','); > return 0; > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/