* [PATCH iproute2 1/2] lib: add root path argument to get_task_name
2026-10-21 15:57 [PATCH iproute2 0/2] use get_task_name in ss Stephen Hemminger
@ 2026-10-21 15:57 ` Stephen Hemminger
2026-10-21 15:57 ` [PATCH iproute2 2/2] ss: use get_task_name instead of parsing stat Stephen Hemminger
2026-10-22 18:30 ` [PATCH iproute2 0/2] use get_task_name in ss patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: Stephen Hemminger @ 2026-10-21 15:57 UTC (permalink / raw)
To: netdev; +Cc: dsahern, Stephen Hemminger
Allow callers to read comm from somewhere other than /proc,
so ss can honor PROC_ROOT and look up per-thread names.
Existing callers pass NULL to keep using /proc.
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
include/utils.h | 2 +-
ip/iptuntap.c | 2 +-
lib/fs.c | 9 +++++++--
rdma/res-cmid.c | 2 +-
rdma/res-cq.c | 2 +-
rdma/res-ctx.c | 2 +-
rdma/res-mr.c | 2 +-
rdma/res-pd.c | 2 +-
rdma/res-qp.c | 2 +-
rdma/res-srq.c | 2 +-
rdma/stat.c | 2 +-
11 files changed, 17 insertions(+), 12 deletions(-)
diff --git a/include/utils.h b/include/utils.h
index 5812d1a8..87b115d9 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -312,7 +312,7 @@ char *find_cgroup2_mount(bool do_mount);
__u64 get_cgroup2_id(const char *path);
char *get_cgroup2_path(__u64 id);
int get_command_name(const char *pid, char *comm, size_t len);
-int get_task_name(pid_t pid, char *name, size_t len);
+int get_task_name(const char *root, pid_t pid, char *name, size_t len);
int get_rtnl_link_stats_rta(struct rtnl_link_stats64 *stats64,
struct rtattr *tb[]);
diff --git a/ip/iptuntap.c b/ip/iptuntap.c
index 0f46fe6a..d1ff48b3 100644
--- a/ip/iptuntap.c
+++ b/ip/iptuntap.c
@@ -315,7 +315,7 @@ static void show_processes(const char *name)
SPRINT_BUF(pname);
open_json_object(NULL);
- if (get_task_name(pid, pname, sizeof(pname)))
+ if (get_task_name(NULL, pid, pname, sizeof(pname)))
print_string(PRINT_ANY, "name",
"%s", "<NULL>");
else
diff --git a/lib/fs.c b/lib/fs.c
index 86f9fb65..a7d23498 100644
--- a/lib/fs.c
+++ b/lib/fs.c
@@ -343,7 +343,11 @@ int get_command_name(const char *pid, char *comm, size_t len)
return 0;
}
-int get_task_name(pid_t pid, char *name, size_t len)
+/*
+ * Read task name from <root>/<pid>/comm.
+ * If root is NULL, use /proc.
+ */
+int get_task_name(const char *root, pid_t pid, char *name, size_t len)
{
char path[PATH_MAX];
FILE *f;
@@ -351,7 +355,8 @@ int get_task_name(pid_t pid, char *name, size_t len)
if (!pid)
return -1;
- if (snprintf(path, sizeof(path), "/proc/%d/comm", pid) >= sizeof(path))
+ if (snprintf(path, sizeof(path), "%s/%d/comm",
+ root ? : "/proc", pid) >= sizeof(path))
return -1;
f = fopen(path, "r");
diff --git a/rdma/res-cmid.c b/rdma/res-cmid.c
index 17a89cc4..da783567 100644
--- a/rdma/res-cmid.c
+++ b/rdma/res-cmid.c
@@ -158,7 +158,7 @@ static int res_cm_id_line(struct rd *rd, const char *name, int idx,
if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
- if (!get_task_name(pid, b, sizeof(b)))
+ if (!get_task_name(NULL, pid, b, sizeof(b)))
comm = b;
} else if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]) {
/* discard const from mnl_attr_get_str */
diff --git a/rdma/res-cq.c b/rdma/res-cq.c
index 0cab3fe0..49f3ef6b 100644
--- a/rdma/res-cq.c
+++ b/rdma/res-cq.c
@@ -86,7 +86,7 @@ static int res_cq_line(struct rd *rd, const char *name, int idx,
if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
- if (!get_task_name(pid, b, sizeof(b)))
+ if (!get_task_name(NULL, pid, b, sizeof(b)))
comm = b;
} else if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]) {
/* discard const from mnl_attr_get_str */
diff --git a/rdma/res-ctx.c b/rdma/res-ctx.c
index 235c837a..e44fd8f7 100644
--- a/rdma/res-ctx.c
+++ b/rdma/res-ctx.c
@@ -20,7 +20,7 @@ static int res_ctx_line(struct rd *rd, const char *name, int idx,
if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
- if (!get_task_name(pid, b, sizeof(b)))
+ if (!get_task_name(NULL, pid, b, sizeof(b)))
comm = b;
} else if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]) {
/* discard const from mnl_attr_get_str */
diff --git a/rdma/res-mr.c b/rdma/res-mr.c
index f6c2534a..17b2242f 100644
--- a/rdma/res-mr.c
+++ b/rdma/res-mr.c
@@ -50,7 +50,7 @@ static int res_mr_line(struct rd *rd, const char *name, int idx,
if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
- if (!get_task_name(pid, b, sizeof(b)))
+ if (!get_task_name(NULL, pid, b, sizeof(b)))
comm = b;
} else if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]) {
/* discard const from mnl_attr_get_str */
diff --git a/rdma/res-pd.c b/rdma/res-pd.c
index 8b9f7aa6..f3a17055 100644
--- a/rdma/res-pd.c
+++ b/rdma/res-pd.c
@@ -36,7 +36,7 @@ static int res_pd_line(struct rd *rd, const char *name, int idx,
if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
- if (!get_task_name(pid, b, sizeof(b)))
+ if (!get_task_name(NULL, pid, b, sizeof(b)))
comm = b;
} else if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]) {
/* discard const from mnl_attr_get_str */
diff --git a/rdma/res-qp.c b/rdma/res-qp.c
index 231ae99c..2593b6ed 100644
--- a/rdma/res-qp.c
+++ b/rdma/res-qp.c
@@ -160,7 +160,7 @@ static int res_qp_line(struct rd *rd, const char *name, int idx,
if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
- if (!get_task_name(pid, b, sizeof(b)))
+ if (!get_task_name(NULL, pid, b, sizeof(b)))
comm = b;
} else if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]) {
/* discard const from mnl_attr_get_str */
diff --git a/rdma/res-srq.c b/rdma/res-srq.c
index 8ab2538a..3c6333ad 100644
--- a/rdma/res-srq.c
+++ b/rdma/res-srq.c
@@ -190,7 +190,7 @@ static int res_srq_line(struct rd *rd, const char *name, int idx,
if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
- if (!get_task_name(pid, b, sizeof(b)))
+ if (!get_task_name(NULL, pid, b, sizeof(b)))
comm = b;
} else if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]) {
/* discard const from mnl_attr_get_str */
diff --git a/rdma/stat.c b/rdma/stat.c
index 2c1bf68e..f2c2d173 100644
--- a/rdma/stat.c
+++ b/rdma/stat.c
@@ -259,7 +259,7 @@ static int res_counter_line(struct rd *rd, const char *name, int index,
if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
- if (!get_task_name(pid, b, sizeof(b)))
+ if (!get_task_name(NULL, pid, b, sizeof(b)))
comm = b;
} else if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]) {
/* discard const from mnl_attr_get_str */
--
2.53.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH iproute2 2/2] ss: use get_task_name instead of parsing stat
2026-10-21 15:57 [PATCH iproute2 0/2] use get_task_name in ss Stephen Hemminger
2026-10-21 15:57 ` [PATCH iproute2 1/2] lib: add root path argument to get_task_name Stephen Hemminger
@ 2026-10-21 15:57 ` Stephen Hemminger
2026-10-22 18:30 ` [PATCH iproute2 0/2] use get_task_name in ss patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: Stephen Hemminger @ 2026-10-21 15:57 UTC (permalink / raw)
To: netdev; +Cc: dsahern, Stephen Hemminger
Parsing /proc/<pid>/stat with fscanf("%*d (%[^)])") is fragile:
the conversion is unbounded and stops at the first ')', so a task
whose name contains ')' is reported truncated.
Use get_task_name() to read comm directly, for both the socket
owner (per-thread with -T) and the netlink socket owner.
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
misc/ss.c | 34 ++++++++++++----------------------
1 file changed, 12 insertions(+), 22 deletions(-)
diff --git a/misc/ss.c b/misc/ss.c
index 26520cee..cffee883 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -592,19 +592,15 @@ static void user_ent_hash_build_task(char *path, int pid, int tid)
sock_context = strdup(no_ctx);
if (task[0] == '\0') {
- char stat[MAX_PATH_LEN];
+ char task_root[MAX_PATH_LEN];
char name[16];
- FILE *fp;
- strlcpy(stat, path, pos_id + 1);
- snprintf(stat + pos_id, sizeof(stat) - pos_id, "stat");
+ /* $PROC_ROOT/$PID/task/$TID/comm */
+ snprintf(task_root, sizeof(task_root), "%s/%d/task",
+ getenv("PROC_ROOT") ? : "/proc", pid);
- fp = fopen(stat, "r");
- if (fp) {
- if (fscanf(fp, "%*d (%[^)])", name) == 1)
- escape_str(task, name, sizeof(task));
- fclose(fp);
- }
+ if (get_task_name(task_root, tid, name, sizeof(name)) == 0)
+ escape_str(task, name, sizeof(task));
}
user_ent_add(ino, task, pid, tid, fd, task_context, sock_context);
@@ -5169,18 +5165,12 @@ static int netlink_show_one(struct filter *f,
done = 1;
strncpy(procname, "kernel", 7);
} else if (pid > 0) {
- FILE *fp;
-
- snprintf(procname, sizeof(procname), "%s/%d/stat",
- getenv("PROC_ROOT") ? : "/proc", pid);
- if ((fp = fopen(procname, "r")) != NULL) {
- if (fscanf(fp, "%*d (%[^)])", procname) == 1) {
- snprintf(procname+strlen(procname),
- sizeof(procname)-strlen(procname),
- "/%d", pid);
- done = 1;
- }
- fclose(fp);
+ if (get_task_name(getenv("PROC_ROOT"), pid,
+ procname, sizeof(procname)) == 0) {
+ snprintf(procname + strlen(procname),
+ sizeof(procname) - strlen(procname),
+ "/%d", pid);
+ done = 1;
}
}
if (!done)
--
2.53.0
^ permalink raw reply related [flat|nested] 4+ messages in thread