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authorDavid S. Miller <davem@davemloft.net>2020-01-24 11:42:18 +0100
committerDavid S. Miller <davem@davemloft.net>2020-01-24 11:42:18 +0100
commit623c8d5c74c69a41573da5a38bb59e8652113f56 (patch)
treebad2d6a9c9497194acdbb3d35835b0c738d7973c
parent2bec445f9bf35e52e395b971df48d3e1e5dc704a (diff)
parent4fc427e0515811250647d44de38d87d7b0e0790f (diff)
downloadlinux-623c8d5c74c69a41573da5a38bb59e8652113f56.tar.gz
Merge branch 'netdev-seq_file-next-functions-should-increase-position-index'
Vasily Averin says: ==================== netdev: seq_file .next functions should increase position index In Aug 2018 NeilBrown noticed commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") "Some ->next functions do not increment *pos when they return NULL... Note that such ->next functions are buggy and should be fixed. A simple demonstration is dd if=/proc/swaps bs=1000 skip=1 Choose any block size larger than the size of /proc/swaps. This will always show the whole last line of /proc/swaps" Described problem is still actual. If you make lseek into middle of last output line following read will output end of last line and whole last line once again. $ dd if=/proc/swaps bs=1 # usual output Filename Type Size Used Priority /dev/dm-0 partition 4194812 97536 -2 104+0 records in 104+0 records out 104 bytes copied $ dd if=/proc/swaps bs=40 skip=1 # last line was generated twice dd: /proc/swaps: cannot skip to specified offset v/dm-0 partition 4194812 97536 -2 /dev/dm-0 partition 4194812 97536 -2 3+1 records in 3+1 records out 131 bytes copied There are lot of other affected files, I've found 30+ including /proc/net/ip_tables_matches and /proc/sysvipc/* This patch-set fixes files related to netdev@ https://bugzilla.kernel.org/show_bug.cgi?id=206283 ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c3
-rw-r--r--drivers/net/ethernet/chelsio/cxgb4/l2t.c3
-rw-r--r--net/atm/proc.c3
-rw-r--r--net/core/neighbour.c1
-rw-r--r--net/ipv4/route.c1
-rw-r--r--net/ipv6/ip6_fib.c7
6 files changed, 7 insertions, 11 deletions
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
index aca9f7a20a2a..4144c230dc97 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
@@ -70,8 +70,7 @@ static void *seq_tab_start(struct seq_file *seq, loff_t *pos)
static void *seq_tab_next(struct seq_file *seq, void *v, loff_t *pos)
{
v = seq_tab_get_idx(seq->private, *pos + 1);
- if (v)
- ++*pos;
+ ++(*pos);
return v;
}
diff --git a/drivers/net/ethernet/chelsio/cxgb4/l2t.c b/drivers/net/ethernet/chelsio/cxgb4/l2t.c
index e9e45006632d..1a16449e9deb 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/l2t.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/l2t.c
@@ -678,8 +678,7 @@ static void *l2t_seq_start(struct seq_file *seq, loff_t *pos)
static void *l2t_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
v = l2t_get_idx(seq, *pos);
- if (v)
- ++*pos;
+ ++(*pos);
return v;
}
diff --git a/net/atm/proc.c b/net/atm/proc.c
index d79221fd4dae..c31896707313 100644
--- a/net/atm/proc.c
+++ b/net/atm/proc.c
@@ -134,8 +134,7 @@ static void vcc_seq_stop(struct seq_file *seq, void *v)
static void *vcc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
v = vcc_walk(seq, 1);
- if (v)
- (*pos)++;
+ (*pos)++;
return v;
}
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 920784a9b7ff..789a73aa7bd8 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -3290,6 +3290,7 @@ static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
*pos = cpu+1;
return per_cpu_ptr(tbl->stats, cpu);
}
+ (*pos)++;
return NULL;
}
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 87e979f2b74a..e356ea779227 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -271,6 +271,7 @@ static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
*pos = cpu+1;
return &per_cpu(rt_cache_stat, cpu);
}
+ (*pos)++;
return NULL;
}
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 7bae6a91b487..cfae0a1529a1 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -2495,14 +2495,13 @@ static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
struct net *net = seq_file_net(seq);
struct ipv6_route_iter *iter = seq->private;
+ ++(*pos);
if (!v)
goto iter_table;
n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next);
- if (n) {
- ++*pos;
+ if (n)
return n;
- }
iter_table:
ipv6_route_check_sernum(iter);
@@ -2510,8 +2509,6 @@ iter_table:
r = fib6_walk_continue(&iter->w);
spin_unlock_bh(&iter->tbl->tb6_lock);
if (r > 0) {
- if (v)
- ++*pos;
return iter->w.leaf;
} else if (r < 0) {
fib6_walker_unlink(net, &iter->w);