Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc fixes from Thomas Gleixner:

  - A fix for a user space regression in /proc/$PID/stat

  - A couple of objtool fixes:
     ~ Plug a memory leak
     ~ Avoid accessing empty sections which upsets certain binutil
       versions
     ~ Prevent corrupting the obj file when section sizes did not change

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  fs/proc: Report eip/esp in /prod/PID/stat for coredumping
  objtool: Fix object file corruption
  objtool: Do not retrieve data from empty sections
  objtool: Fix memory leak in elf_create_rela_section()

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 88c3555..525157c 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -62,6 +62,7 @@
 #include <linux/mman.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/numa_balancing.h>
+#include <linux/sched/task_stack.h>
 #include <linux/sched/task.h>
 #include <linux/sched/cputime.h>
 #include <linux/proc_fs.h>
@@ -421,7 +422,15 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 		 * esp and eip are intentionally zeroed out.  There is no
 		 * non-racy way to read them without freezing the task.
 		 * Programs that need reliable values can use ptrace(2).
+		 *
+		 * The only exception is if the task is core dumping because
+		 * a program is not able to use ptrace(2) in that case. It is
+		 * safe because the task has stopped executing permanently.
 		 */
+		if (permitted && (task->flags & PF_DUMPCORE)) {
+			eip = KSTK_EIP(task);
+			esp = KSTK_ESP(task);
+		}
 	}
 
 	get_task_comm(tcomm, task);