On Fri, Dec 18, 2009 at 06:27:47PM +0100, Oleg Nesterov wrote: > On 12/18, Frederic Weisbecker wrote: > > > > On Fri, Dec 18, 2009 at 01:56:50AM +0100, Oleg Nesterov wrote: > > > Hi.
<snipped> > > Single stepping works well for me, after a quick check on > > gdb. How did you trigger the bug? > > Please find the trivial test-case below. It hangs, because > PTRACE_SINGLESTEP doesn't trigger the trap. > aah...my other mail just criss-crossed yours. I quickly ran on the said x86 box, loaded with -tip (commit 7818b3d0fc68f5c2a85fed86d9fa37131c5a3068) and it runs fine. [r...@llm05 prasadkr]# cat oleg.c #include <stdio.h> #include <unistd.h> #include <signal.h> #include <sys/ptrace.h> #include <sys/wait.h> #include <assert.h> int main(void) { int pid, status, i; pid = fork(); if (!pid) for (;;); sleep(1); assert(ptrace(PTRACE_ATTACH, pid, 0,0) == 0); assert(pid == wait(&status)); assert(WIFSTOPPED(status)); for (i = 0; i < 10; ++i) { assert(ptrace(PTRACE_SINGLESTEP, pid, 0,0) == 0); printf("wait %d ...\n", i); assert(pid == wait(&status)); assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGTRAP); } kill(pid, SIGKILL); return 0; } [r...@llm05 prasadkr]# gcc -o oleg oleg.c -g -Wall [r...@llm05 prasadkr]# ./oleg wait 0 ... wait 1 ... wait 2 ... wait 3 ... wait 4 ... wait 5 ... wait 6 ... wait 7 ... wait 8 ... wait 9 ... [r...@llm05 prasadkr]# Am I missing something here? Thanks, K.Prasad