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[PATCH v4 23/57] proc: fix return address printk conversion specifer in /proc/<pid>/stack

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When printing call return addresses found on a stack, /proc/<pid>/stack
can sometimes give a confusing result.  If the call instruction was the
last instruction in the function (which can happen when calling a
noreturn function), '%pS' will incorrectly display the name of the
function which happens to be next in the object code, rather than the
name of the actual calling function.

Use '%pB' instead, which was created for this exact purpose.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 fs/proc/base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 54e2702..e9ff186 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -483,7 +483,7 @@ static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
 		save_stack_trace_tsk(task, &trace);
 
 		for (i = 0; i < trace.nr_entries; i++) {
-			seq_printf(m, "[<%pK>] %pS\n",
+			seq_printf(m, "[<%pK>] %pB\n",
 				   (void *)entries[i], (void *)entries[i]);
 		}
 		unlock_trace(task);
-- 
2.7.4

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[PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:20 +0200
  [PATCH v4 52/57] x86/dumpstack: warn on stack recursion Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:20 +0200
  [PATCH v4 46/57] x86/dumpstack: fix duplicate RIP address display in __show_regs() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:20 +0200
  [PATCH v4 28/57] x86/dumpstack/ftrace: convert dump_trace() callbacks to use ftrace_graph_ret_addr() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 29/57] ftrace/x86: implement HAVE_FUNCTION_GRAPH_RET_ADDR_PTR Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 26/57] ftrace: add return address pointer to ftrace_ret_stack Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 34/57] x86/dumpstack: add get_stack_info() interface Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 23/57] proc: fix return address printk conversion specifer in /proc/<pid>/stack Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 36/57] x86/unwind: add new unwind interface and implementations Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 21/57] perf/x86: check perf_callchain_store() error Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 33/57] x86/dumpstack: simplify in_exception_stack() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 27/57] ftrace: add ftrace_graph_ret_addr() stack unwinding helpers Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 19/57] x86/entry/head/32: use local labels Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 25/57] ftrace: only allocate the ret_stack 'fp' field when needed Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 16/57] x86/entry/32: fix the end of the stack for newly forked tasks Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 40/57] x86/dumpstack: convert show_trace_log_lvl() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 39/57] oprofile/x86: convert x86_backtrace() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 35/57] x86/dumpstack: add recursion checking for all stacks Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 22/57] oprofile/x86: add regs->ip to oprofile trace Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 38/57] x86/stacktrace: convert save_stack_trace_*() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 24/57] ftrace: remove CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST from config Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 45/57] x86/dumpstack: print any pt_regs found on the stack Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 30/57] x86/dumpstack/ftrace: mark function graph handler function as unreliable Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 47/57] x86/dumpstack: print orig_ax in __show_regs() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 44/57] x86/dumpstack: print stack identifier on its own line Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code Frederic Weisbecker <fweisbec@gmail.com> - 2016-08-18 15:30 +0200
    Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code Ingo Molnar <mingo@kernel.org> - 2016-08-18 15:40 +0200
      Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code Steven Rostedt <rostedt@goodmis.org> - 2016-08-18 16:40 +0200
      Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 16:40 +0200
        Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code Steven Rostedt <rostedt@goodmis.org> - 2016-08-18 16:50 +0200
        Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code Ingo Molnar <mingo@kernel.org> - 2016-08-19 07:10 +0200
  [PATCH v4 41/57] x86/dumpstack: remove dump_trace() and related callbacks Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 31/57] x86/dumpstack/ftrace: don't print unreliable addresses in print_context_stack_bp() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 42/57] x86/entry/unwind: create stack frames for saved interrupt registers Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 20/57] x86/entry/32: rename 'error_code' to 'common_exception' Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 37/57] perf/x86: convert perf_callchain_kernel() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 32/57] x86/dumpstack: allow preemption in show_stack_log_lvl() and dump_trace() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:30 +0200
  [PATCH v4 12/57] x86: move _stext marker to before head code Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:40 +0200
  [PATCH v4 09/57] x86/dumpstack: fix x86_32 kernel_stack_pointer() previous stack access Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:40 +0200

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