From: Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>
From: Bodo Stroesser <bstroesser@fujitsu-siemens.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>
Cc: Ulrich Drepper <drepper@redhat.com>
Using NPTL, getpid() sometimes delivers the wrong pid, since it uses the
one buffered in TLS from previous calls. This buffered pid isn't
discarded, when a child is created by a clone().
So, as a workaround, UML should use a direct kernel call to bypass the lib.
Also, I (Paolo) went replacing all remaining calls of getpid() with
os_getpid(), to make sure they use the syscall and not the normal glibc
definition.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/um/kernel/frame.c | 8 ++++----
25-akpm/arch/um/kernel/main.c | 3 ++-
25-akpm/arch/um/kernel/skas/process.c | 2 +-
25-akpm/arch/um/os-Linux/process.c | 4 ++++
4 files changed, 11 insertions(+), 6 deletions(-)
diff -puN arch/um/kernel/frame.c~uml-use-sys_getpid-bypassing-glibc-fixes-uml-on-gentoo arch/um/kernel/frame.c
--- 25/arch/um/kernel/frame.c~uml-use-sys_getpid-bypassing-glibc-fixes-uml-on-gentoo Wed Nov 10 13:40:04 2004
+++ 25-akpm/arch/um/kernel/frame.c Wed Nov 10 13:40:04 2004
@@ -140,7 +140,7 @@ static void child_common(struct common_r
}
if(sigaltstack(&ss, NULL) < 0){
printf("sigaltstack failed - errno = %d\n", errno);
- kill(getpid(), SIGKILL);
+ kill(os_getpid(), SIGKILL);
}
if(restorer){
@@ -162,7 +162,7 @@ static void child_common(struct common_r
if(err < 0){
printf("sigaction failed - errno = %d\n", errno);
- kill(getpid(), SIGKILL);
+ kill(os_getpid(), SIGKILL);
}
os_stop_process(os_getpid());
@@ -191,7 +191,7 @@ static void sc_handler(int sig, struct s
setup_arch_frame_raw(&raw_sc->common.arch, &sc + 1, raw_sc->common.sr);
os_stop_process(os_getpid());
- kill(getpid(), SIGKILL);
+ kill(os_getpid(), SIGKILL);
}
static int sc_child(void *arg)
@@ -229,7 +229,7 @@ static void si_handler(int sig, siginfo_
ucontext->uc_mcontext.fpregs, raw_si->common.sr);
os_stop_process(os_getpid());
- kill(getpid(), SIGKILL);
+ kill(os_getpid(), SIGKILL);
}
static int si_child(void *arg)
diff -puN arch/um/kernel/main.c~uml-use-sys_getpid-bypassing-glibc-fixes-uml-on-gentoo arch/um/kernel/main.c
--- 25/arch/um/kernel/main.c~uml-use-sys_getpid-bypassing-glibc-fixes-uml-on-gentoo Wed Nov 10 13:40:04 2004
+++ 25-akpm/arch/um/kernel/main.c Wed Nov 10 13:40:04 2004
@@ -26,6 +26,7 @@
#include "uml-config.h"
#include "irq_user.h"
#include "time_user.h"
+#include "os.h"
/* Set in set_stklim, which is called from main and __wrap_malloc.
* __wrap_malloc only calls it if main hasn't started.
@@ -175,7 +176,7 @@ int main(int argc, char **argv, char **e
}
#define CAN_KMALLOC() \
- (kmalloc_ok && CHOOSE_MODE((getpid() != tracing_pid), 1))
+ (kmalloc_ok && CHOOSE_MODE((os_getpid() != tracing_pid), 1))
extern void *__real_malloc(int);
diff -puN arch/um/kernel/skas/process.c~uml-use-sys_getpid-bypassing-glibc-fixes-uml-on-gentoo arch/um/kernel/skas/process.c
--- 25/arch/um/kernel/skas/process.c~uml-use-sys_getpid-bypassing-glibc-fixes-uml-on-gentoo Wed Nov 10 13:40:04 2004
+++ 25-akpm/arch/um/kernel/skas/process.c Wed Nov 10 13:40:04 2004
@@ -30,7 +30,7 @@
int is_skas_winch(int pid, int fd, void *data)
{
- if(pid != getpid())
+ if(pid != os_getpid())
return(0);
register_winch_irq(-1, fd, -1, data);
diff -puN arch/um/os-Linux/process.c~uml-use-sys_getpid-bypassing-glibc-fixes-uml-on-gentoo arch/um/os-Linux/process.c
--- 25/arch/um/os-Linux/process.c~uml-use-sys_getpid-bypassing-glibc-fixes-uml-on-gentoo Wed Nov 10 13:40:04 2004
+++ 25-akpm/arch/um/os-Linux/process.c Wed Nov 10 13:40:04 2004
@@ -107,6 +107,10 @@ void os_usr1_process(int pid)
kill(pid, SIGUSR1);
}
+/*Don't use the glibc version, which caches the result in TLS. It misses some
+ * syscalls, and also breaks with clone(), which does not unshare the TLS.*/
+inline _syscall0(pid_t, getpid)
+
int os_getpid(void)
{
return(getpid());
_