linux/arch/x86/kernel/unwind_guess.c
Josh Poimboeuf cfee9eddcd x86/unwind: Fix oprofile module link error
When compiling on x86 with CONFIG_OPROFILE=m and CONFIG_FRAME_POINTER=n,
the oprofile module fails to link:

  ERROR: ftrace_graph_ret_addr" [arch/x86/oprofile/oprofile.ko] undefined!

The problem was introduced when oprofile was converted to use the new
x86 unwinder.  When frame pointers are disabled, the "guess" unwinder's
unwind_get_return_address() is an inline function which calls
ftrace_graph_ret_addr(), which is not exported.

Fix it by converting the "guess" version of unwind_get_return_address()
to an exported out-of-line function, just like its frame pointer
counterpart.

Reported-by: Karl Beldan <karl.beldan@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: ec2ad9ccf1 ("oprofile/x86: Convert x86_backtrace() to use the new unwinder")
Link: http://lkml.kernel.org/r/be08d589f6474df78364e081c42777e382af9352.1475731632.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-06 09:52:20 +02:00

54 lines
1.2 KiB
C

#include <linux/sched.h>
#include <linux/ftrace.h>
#include <asm/ptrace.h>
#include <asm/bitops.h>
#include <asm/stacktrace.h>
#include <asm/unwind.h>
unsigned long unwind_get_return_address(struct unwind_state *state)
{
if (unwind_done(state))
return 0;
return ftrace_graph_ret_addr(state->task, &state->graph_idx,
*state->sp, state->sp);
}
EXPORT_SYMBOL_GPL(unwind_get_return_address);
bool unwind_next_frame(struct unwind_state *state)
{
struct stack_info *info = &state->stack_info;
if (unwind_done(state))
return false;
do {
for (state->sp++; state->sp < info->end; state->sp++)
if (__kernel_text_address(*state->sp))
return true;
state->sp = info->next_sp;
} while (!get_stack_info(state->sp, state->task, info,
&state->stack_mask));
return false;
}
EXPORT_SYMBOL_GPL(unwind_next_frame);
void __unwind_start(struct unwind_state *state, struct task_struct *task,
struct pt_regs *regs, unsigned long *first_frame)
{
memset(state, 0, sizeof(*state));
state->task = task;
state->sp = first_frame;
get_stack_info(first_frame, state->task, &state->stack_info,
&state->stack_mask);
if (!__kernel_text_address(*first_frame))
unwind_next_frame(state);
}
EXPORT_SYMBOL_GPL(__unwind_start);