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On trap while inside ddb, the trap handler calls kdb_reenter(), that

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longjmp to the default context. As result, "alltrace" command may
be prematurely terminated (without error message). This is happens,
for instance, when system is low on memory and referenced page in
kernel-mode thread stack is swapped out.

Protect "alltrace" against termination on trap by setting temporary
kdb_jmpbuf context.

Submitted by:	Peter Holm
This commit is contained in:
Konstantin Belousov 2006-11-02 11:47:38 +00:00
parent 42db1b70c5
commit 9641e38966
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=163909
1 changed files with 14 additions and 6 deletions
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20
sys/ddb/db_command.c
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@ -690,14 +690,22 @@ db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
{
struct proc *p;
struct thread *td;
jmp_buf jb;
void *prev_jb;
LIST_FOREACH(p, &allproc, p_list) {
FOREACH_THREAD_IN_PROC(p, td) {
db_printf("\nTracing command %s pid %d tid %ld td %p\n",
p->p_comm, p->p_pid, (long)td->td_tid, td);
db_trace_thread(td, -1);
if (db_pager_quit)
return;
prev_jb = kdb_jmpbuf(jb);
if (setjmp(jb) == 0) {
FOREACH_THREAD_IN_PROC(p, td) {
db_printf("\nTracing command %s pid %d tid %ld td %p\n",
p->p_comm, p->p_pid, (long)td->td_tid, td);
db_trace_thread(td, -1);
if (db_pager_quit) {
kdb_jmpbuf(prev_jb);
return;
}
}
}
kdb_jmpbuf(prev_jb);
}
}