| Message ID | 20231006141246.3747944-1-kory.maincent@bootlin.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v2,1/1] ethtool: Fix mod state of verbose no_mask bitset | expand |
On Fri, Oct 06, 2023 at 04:12:46PM +0200, Köry Maincent wrote: > From: Kory Maincent <kory.maincent@bootlin.com> > > A bitset without mask in a _SET request means we want exactly the bits in > the bitset to be set. This works correctly for compact format but when > verbose format is parsed, ethnl_update_bitset32_verbose() only sets the > bits present in the request bitset but does not clear the rest. The commit > 6699170376ab fixes this issue by clearing the whole target bitmap before we > start iterating. The solution proposed brought an issue with the behavior > of the mod variable. As the bitset is always cleared the old val will > always differ to the new val. > > Fix it by adding a new temporary variable which save the state of the old > bitmap. > > Fixes: 6699170376ab ("ethtool: fix application of verbose no_mask bitset") > Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> > --- > > Changes in v2: > - Fix the allocated size. > --- > net/ethtool/bitset.c | 31 +++++++++++++++++++++++++------ > 1 file changed, 25 insertions(+), 6 deletions(-) > > diff --git a/net/ethtool/bitset.c b/net/ethtool/bitset.c > index 0515d6604b3b..8a6b35c920cd 100644 > --- a/net/ethtool/bitset.c > +++ b/net/ethtool/bitset.c > @@ -432,7 +432,9 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, > struct netlink_ext_ack *extack, bool *mod) > { > struct nlattr *bit_attr; > + u32 *tmp = NULL; > bool no_mask; > + bool dummy; > int rem; > int ret; > > @@ -448,8 +450,16 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, > } > > no_mask = tb[ETHTOOL_A_BITSET_NOMASK]; > - if (no_mask) > - ethnl_bitmap32_clear(bitmap, 0, nbits, mod); > + if (no_mask) { > + unsigned int nwords = DIV_ROUND_UP(nbits, 32); > + unsigned int nbytes = nwords * sizeof(u32); Hi Köry, Thanks for addressing my concerns regarding the size calculations in v1. I think that a comment is warranted describing the fact that only the map, and not the mask part, is taken into account in the size calculations above. > + > + tmp = kcalloc(nwords, sizeof(u32), GFP_KERNEL); > + if (!tmp) > + return -ENOMEM; > + memcpy(tmp, bitmap, nbytes); > + ethnl_bitmap32_clear(bitmap, 0, nbits, &dummy); > + } Perhaps we could consider something line the following. Which would avoid the need for the n_mask condition in the nla_for_each_nested() loop further below. ... saved_bitmap = kcalloc(nwords, sizeof(u32), GFP_KERNEL); if (!saved_bitmap) return -ENOMEM; memcpy(saved_bitmap, bitmap, nbytes); ethnl_bitmap32_clear(bitmap, 0, nbits, &dummy); orig_bitmap = saved_bitmap; } else { orig_bitmap = bitmap; } (Choosing names for variables seems hard today.) > > nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) { > bool old_val, new_val; > @@ -458,13 +468,19 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, > if (nla_type(bit_attr) != ETHTOOL_A_BITSET_BITS_BIT) { > NL_SET_ERR_MSG_ATTR(extack, bit_attr, > "only ETHTOOL_A_BITSET_BITS_BIT allowed in ETHTOOL_A_BITSET_BITS"); > - return -EINVAL; > + ret = -EINVAL; > + goto out; > } > ret = ethnl_parse_bit(&idx, &new_val, nbits, bit_attr, no_mask, > names, extack); > if (ret < 0) > - return ret; > - old_val = bitmap[idx / 32] & ((u32)1 << (idx % 32)); > + goto out; > + > + if (no_mask) > + old_val = tmp[idx / 32] & ((u32)1 << (idx % 32)); > + else > + old_val = bitmap[idx / 32] & ((u32)1 << (idx % 32)); > + > if (new_val != old_val) { > if (new_val) > bitmap[idx / 32] |= ((u32)1 << (idx % 32)); > @@ -474,7 +490,10 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, > } > } > > - return 0; > + ret = 0; > +out: > + kfree(tmp); > + return ret; > } > > static int ethnl_compact_sanity_checks(unsigned int nbits, > -- > 2.25.1 >
diff --git a/net/ethtool/bitset.c b/net/ethtool/bitset.c index 0515d6604b3b..8a6b35c920cd 100644 --- a/net/ethtool/bitset.c +++ b/net/ethtool/bitset.c @@ -432,7 +432,9 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, struct netlink_ext_ack *extack, bool *mod) { struct nlattr *bit_attr; + u32 *tmp = NULL; bool no_mask; + bool dummy; int rem; int ret; @@ -448,8 +450,16 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, } no_mask = tb[ETHTOOL_A_BITSET_NOMASK]; - if (no_mask) - ethnl_bitmap32_clear(bitmap, 0, nbits, mod); + if (no_mask) { + unsigned int nwords = DIV_ROUND_UP(nbits, 32); + unsigned int nbytes = nwords * sizeof(u32); + + tmp = kcalloc(nwords, sizeof(u32), GFP_KERNEL); + if (!tmp) + return -ENOMEM; + memcpy(tmp, bitmap, nbytes); + ethnl_bitmap32_clear(bitmap, 0, nbits, &dummy); + } nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) { bool old_val, new_val; @@ -458,13 +468,19 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, if (nla_type(bit_attr) != ETHTOOL_A_BITSET_BITS_BIT) { NL_SET_ERR_MSG_ATTR(extack, bit_attr, "only ETHTOOL_A_BITSET_BITS_BIT allowed in ETHTOOL_A_BITSET_BITS"); - return -EINVAL; + ret = -EINVAL; + goto out; } ret = ethnl_parse_bit(&idx, &new_val, nbits, bit_attr, no_mask, names, extack); if (ret < 0) - return ret; - old_val = bitmap[idx / 32] & ((u32)1 << (idx % 32)); + goto out; + + if (no_mask) + old_val = tmp[idx / 32] & ((u32)1 << (idx % 32)); + else + old_val = bitmap[idx / 32] & ((u32)1 << (idx % 32)); + if (new_val != old_val) { if (new_val) bitmap[idx / 32] |= ((u32)1 << (idx % 32)); @@ -474,7 +490,10 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, } } - return 0; + ret = 0; +out: + kfree(tmp); + return ret; } static int ethnl_compact_sanity_checks(unsigned int nbits,