Re: [PATCH net] net: igmp: increase size of mr_ifc_count
From: Guenter Roeck <linux@roeck-us.net>
Date: 2021-08-11 20:14:54
On Wed, Aug 11, 2021 at 12:57:15PM -0700, Eric Dumazet wrote:
From: Eric Dumazet <edumazet@google.com>
Some arches support cmpxchg() on 4-byte and 8-byte only.
Increase mr_ifc_count width to 32bit to fix this problem.
Fixes: 4a2b285e7e10 ("net: igmp: fix data-race in igmp_ifc_timer_expire()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>This patch fixes the build problems I had observed. Tested-by: Guenter Roeck <linux@roeck-us.net> Thanks, Guenter
quoted hunk
--- include/linux/inetdevice.h | 2 +- net/ipv4/igmp.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h index 53aa0343bf694cb817e00ff597b52ce046e29d2c..aaf4f1b4c277c4ad38e1f0742bb480d3bb003287 100644 --- a/include/linux/inetdevice.h +++ b/include/linux/inetdevice.h@@ -41,7 +41,7 @@ struct in_device { unsigned long mr_qri; /* Query Response Interval */ unsigned char mr_qrv; /* Query Robustness Variable */ unsigned char mr_gq_running; - unsigned char mr_ifc_count; + u32 mr_ifc_count; struct timer_list mr_gq_timer; /* general query timer */ struct timer_list mr_ifc_timer; /* interface change timer */diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index a51360087b19845a28408c827032e08dabf99838..00576bae183d30518e376ad3846d4fe6025aaea7 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c@@ -803,7 +803,7 @@ static void igmp_gq_timer_expire(struct timer_list *t) static void igmp_ifc_timer_expire(struct timer_list *t) { struct in_device *in_dev = from_timer(in_dev, t, mr_ifc_timer); - u8 mr_ifc_count; + u32 mr_ifc_count; igmpv3_send_cr(in_dev); restart:-- 2.32.0.605.g8dce9f2422-goog