From: Paolo Abeni <pabeni@redhat.com>
Date: Mon, 21 Jan 2019 12:36:12 +0100
Subject: bpftool: fix percpu maps updating
Patch-mainline: v5.0-rc6
Git-commit: b0ca5ecb8e2279d706261f525f1bd0ba9e3fe800
References: bsc#1109837
When updating a percpu map, bpftool currently copies the provided
value only into the first per CPU copy of the specified value,
all others instances are left zeroed.
This change explicitly copies the user-provided bytes to all the
per CPU instances, keeping the sub-command syntax unchanged.
v2 -> v3:
- drop unused argument, as per Quentin's suggestion
v1 -> v2:
- rename the helper as per Quentin's suggestion
Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
tools/bpf/bpftool/map.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -268,6 +268,20 @@ static char **parse_bytes(char **argv, c
return argv + i;
}
+/* on per cpu maps we must copy the provided value on all value instances */
+static void fill_per_cpu_value(struct bpf_map_info *info, void *value)
+{
+ unsigned int i, n, step;
+
+ if (!map_is_per_cpu(info->type))
+ return;
+
+ n = get_possible_cpus();
+ step = round_up(info->value_size, 8);
+ for (i = 1; i < n; i++)
+ memcpy(value + i * step, value, info->value_size);
+}
+
static int parse_elem(char **argv, struct bpf_map_info *info,
void *key, void *value, __u32 key_size, __u32 value_size,
__u32 *flags, __u32 **value_fd)
@@ -347,6 +361,8 @@ static int parse_elem(char **argv, struc
argv = parse_bytes(argv, "value", value, value_size);
if (!argv)
return -1;
+
+ fill_per_cpu_value(info, value);
}
return parse_elem(argv, info, key, NULL, key_size, value_size,