[PATCH v2] kdb: Use newer api for tasklist scanning

From: Davidlohr Bueso
Date: Mon Sep 07 2020 - 16:48:46 EST


This kills using the do_each_thread/while_each_thread combo to
iterate all threads and uses for_each_process_thread() instead,
maintaining semantics. while_each_thread() is ultimately racy
and deprecated; although in this particular case there is no
concurrency so it doesn't matter. Still lets trivially get rid
of two more users.

Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
kernel/debug/gdbstub.c | 4 ++--
kernel/debug/kdb/kdb_bt.c | 4 ++--
kernel/debug/kdb/kdb_main.c | 8 ++++----
kernel/debug/kdb/kdb_private.h | 4 ----
4 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index cc3c43dfec44..b52ebff09ac8 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -725,7 +725,7 @@ static void gdb_cmd_query(struct kgdb_state *ks)
}
}

- do_each_thread(g, p) {
+ for_each_process_thread(g, p) {
if (i >= ks->thr_query && !finished) {
int_to_threadref(thref, p->pid);
ptr = pack_threadid(ptr, thref);
@@ -735,7 +735,7 @@ static void gdb_cmd_query(struct kgdb_state *ks)
finished = 1;
}
i++;
- } while_each_thread(g, p);
+ }

*(--ptr) = '\0';
break;
diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c
index 18e03aba2cfc..1f9f0e47aeda 100644
--- a/kernel/debug/kdb/kdb_bt.c
+++ b/kernel/debug/kdb/kdb_bt.c
@@ -149,14 +149,14 @@ kdb_bt(int argc, const char **argv)
return 0;
}
/* Now the inactive tasks */
- kdb_do_each_thread(g, p) {
+ for_each_process_thread(g, p) {
if (KDB_FLAG(CMD_INTERRUPT))
return 0;
if (task_curr(p))
continue;
if (kdb_bt1(p, mask, btaprompt))
return 0;
- } kdb_while_each_thread(g, p);
+ }
} else if (strcmp(argv[0], "btp") == 0) {
struct task_struct *p;
unsigned long pid;
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 5c7949061671..930ac1b25ec7 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2299,10 +2299,10 @@ void kdb_ps_suppressed(void)
if (kdb_task_state(p, mask_I))
++idle;
}
- kdb_do_each_thread(g, p) {
+ for_each_process_thread(g, p) {
if (kdb_task_state(p, mask_M))
++daemon;
- } kdb_while_each_thread(g, p);
+ }
if (idle || daemon) {
if (idle)
kdb_printf("%d idle process%s (state I)%s\n",
@@ -2370,12 +2370,12 @@ static int kdb_ps(int argc, const char **argv)
}
kdb_printf("\n");
/* Now the real tasks */
- kdb_do_each_thread(g, p) {
+ for_each_process_thread(g, p) {
if (KDB_FLAG(CMD_INTERRUPT))
return 0;
if (kdb_task_state(p, mask))
kdb_ps1(p);
- } kdb_while_each_thread(g, p);
+ }

return 0;
}
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 2e296e4a234c..a4281fb99299 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -230,10 +230,6 @@ extern struct task_struct *kdb_curr_task(int);

#define kdb_task_has_cpu(p) (task_curr(p))

-/* Simplify coexistence with NPTL */
-#define kdb_do_each_thread(g, p) do_each_thread(g, p)
-#define kdb_while_each_thread(g, p) while_each_thread(g, p)
-
#define GFP_KDB (in_interrupt() ? GFP_ATOMIC : GFP_KERNEL)

extern void *debug_kmalloc(size_t size, gfp_t flags);
--
2.26.2