Fedora broke PTRACE_SYSEMU again, and UML crashes as a result when it
doesn't need to. This patch makes the PTRACE_SYSEMU check fail
gracefully and makes UML fall back to PTRACE_SYSCALL.
Signed-off-by: Jeff Dike <[email protected]>
---
arch/um/os-Linux/start_up.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
Index: linux-2.6.22/arch/um/os-Linux/start_up.c
===================================================================
--- linux-2.6.22.orig/arch/um/os-Linux/start_up.c 2008-06-10 11:42:06.000000000 -0400
+++ linux-2.6.22/arch/um/os-Linux/start_up.c 2008-06-10 12:16:57.000000000 -0400
@@ -121,8 +121,10 @@ static int stop_ptraced_child(int pid, i
{
int status, n, ret = 0;
- if (ptrace(PTRACE_CONT, pid, 0, 0) < 0)
- fatal_perror("stop_ptraced_child : ptrace failed");
+ if (ptrace(PTRACE_CONT, pid, 0, 0) < 0) {
+ perror("stop_ptraced_child : ptrace failed");
+ return -1;
+ }
CATCH_EINTR(n = waitpid(pid, &status, 0));
if (!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
int exit_with = WEXITSTATUS(status);
@@ -212,7 +214,7 @@ static void __init check_sysemu(void)
if (n < 0)
fatal_perror("check_sysemu : wait failed");
if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
- fatal("check_sysemu : expected SIGTRAP, got status = %d",
+ fatal("check_sysemu : expected SIGTRAP, got status = %d\n",
status);
if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
@@ -254,9 +256,11 @@ static void __init check_sysemu(void)
if (WIFSTOPPED(status) &&
(WSTOPSIG(status) == (SIGTRAP|0x80))) {
- if (!count)
- fatal("check_ptrace : SYSEMU_SINGLESTEP "
- "doesn't singlestep");
+ if (!count) {
+ non_fatal("check_ptrace : SYSEMU_SINGLESTEP "
+ "doesn't singlestep");
+ goto fail;
+ }
n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
os_getpid());
if (n < 0)
@@ -266,9 +270,12 @@ static void __init check_sysemu(void)
}
else if (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
count++;
- else
- fatal("check_ptrace : expected SIGTRAP or "
- "(SIGTRAP | 0x80), got status = %d", status);
+ else {
+ non_fatal("check_ptrace : expected SIGTRAP or "
+ "(SIGTRAP | 0x80), got status = %d\n",
+ status);
+ goto fail;
+ }
}
if (stop_ptraced_child(pid, 0, 0) < 0)
goto fail_stopped;