diff mbox series

[net-next,3/3] ipv6: mcast: annotate data-race around psf->sf_count[MCAST_XXX]

Message ID 20241210183352.86530-4-edumazet@google.com (mailing list archive)
State Accepted
Commit 00bf2032e97691c4b53427b33a85b134324e2a94
Delegated to: Netdev Maintainers
Headers show
Series ipv6: mcast: add data-race annotations | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 36 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-12-12--00-00 (tests: 795)

Commit Message

Eric Dumazet Dec. 10, 2024, 6:33 p.m. UTC 
psf->sf_count[MCAST_XXX] fields are read locklessly from
ipv6_chk_mcast_addr() and igmp6_mcf_seq_show().

Add READ_ONCE() and WRITE_ONCE() annotations accordingly.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv6/mcast.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

David Ahern Dec. 11, 2024, 3:55 a.m. UTC | #1 
On 12/10/24 11:33 AM, Eric Dumazet wrote:
> psf->sf_count[MCAST_XXX] fields are read locklessly from
> ipv6_chk_mcast_addr() and igmp6_mcf_seq_show().
> 
> Add READ_ONCE() and WRITE_ONCE() annotations accordingly.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  net/ipv6/mcast.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>
diff mbox series

Patch

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 09622142b0705bd81491f148dde4612c0f8fddb8..5ca8692d565d5055eeebef2a547ced217d81c7d4 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1037,8 +1037,8 @@  bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
 				break;
 		}
 		if (psf)
-			rv = psf->sf_count[MCAST_INCLUDE] ||
-				psf->sf_count[MCAST_EXCLUDE] !=
+			rv = READ_ONCE(psf->sf_count[MCAST_INCLUDE]) ||
+				READ_ONCE(psf->sf_count[MCAST_EXCLUDE]) !=
 				READ_ONCE(mc->mca_sfcount[MCAST_EXCLUDE]);
 		else
 			rv = READ_ONCE(mc->mca_sfcount[MCAST_EXCLUDE]) != 0;
@@ -2287,7 +2287,7 @@  static int ip6_mc_del1_src(struct ifmcaddr6 *pmc, int sfmode,
 		/* source filter not found, or count wrong =>  bug */
 		return -ESRCH;
 	}
-	psf->sf_count[sfmode]--;
+	WRITE_ONCE(psf->sf_count[sfmode], psf->sf_count[sfmode] - 1);
 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
 		struct inet6_dev *idev = pmc->idev;
 
@@ -2393,7 +2393,7 @@  static int ip6_mc_add1_src(struct ifmcaddr6 *pmc, int sfmode,
 			rcu_assign_pointer(pmc->mca_sources, psf);
 		}
 	}
-	psf->sf_count[sfmode]++;
+	WRITE_ONCE(psf->sf_count[sfmode], psf->sf_count[sfmode] + 1);
 	return 0;
 }
 
@@ -3079,8 +3079,8 @@  static int igmp6_mcf_seq_show(struct seq_file *seq, void *v)
 			   state->dev->ifindex, state->dev->name,
 			   &state->im->mca_addr,
 			   &psf->sf_addr,
-			   psf->sf_count[MCAST_INCLUDE],
-			   psf->sf_count[MCAST_EXCLUDE]);
+			   READ_ONCE(psf->sf_count[MCAST_INCLUDE]),
+			   READ_ONCE(psf->sf_count[MCAST_EXCLUDE]));
 	}
 	return 0;
 }