powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR

This associates entries in the ftrace_ret_stack with corresponding stack
frames, enabling more robust stack unwinding. Also update the only user
of ftrace_graph_ret_addr() to pass the stack pointer.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0224f2d0971b069c678e2ff678cfc2cd1e114cfe.1567707399.git.naveen.n.rao@linux.vnet.ibm.com
This commit is contained in:
Naveen N. Rao 2019-09-05 23:50:29 +05:30 committed by Michael Ellerman
parent a3db31ff6c
commit 370011a270
7 changed files with 11 additions and 4 deletions

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@ -134,7 +134,8 @@ extern int __ucmpdi2(u64, u64);
/* tracing */
void _mcount(void);
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip);
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
unsigned long sp);
void pnv_power9_force_smt4_catch(void);
void pnv_power9_force_smt4_release(void);

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@ -8,6 +8,8 @@
#define MCOUNT_ADDR ((unsigned long)(_mcount))
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#ifdef __ASSEMBLY__
/* Based off of objdump optput from glibc */

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@ -182,7 +182,7 @@ static int __save_stack_trace_tsk_reliable(struct task_struct *tsk,
* FIXME: IMHO these tests do not belong in
* arch-dependent code, they are generic.
*/
ip = ftrace_graph_ret_addr(tsk, &graph_idx, ip, NULL);
ip = ftrace_graph_ret_addr(tsk, &graph_idx, ip, stack);
#ifdef CONFIG_KPROBES
/*
* Mark stacktraces with kretprobed functions on them

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@ -944,7 +944,8 @@ int ftrace_disable_ftrace_graph_caller(void)
* Hook the return address and push it in the stack of return addrs
* in current thread info. Return the address we want to divert to.
*/
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
unsigned long sp)
{
unsigned long return_hooker;
@ -956,7 +957,7 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
return_hooker = ppc_function_entry(return_to_handler);
if (!function_graph_enter(parent, ip, 0, NULL))
if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp))
parent = return_hooker;
out:
return parent;

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@ -50,6 +50,7 @@ _GLOBAL(ftrace_stub)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
_GLOBAL(ftrace_graph_caller)
addi r5, r1, 48
/* load r4 with local address */
lwz r4, 44(r1)
subi r4, r4, MCOUNT_INSN_SIZE

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@ -294,6 +294,7 @@ _GLOBAL(ftrace_graph_caller)
std r2, 24(r1)
ld r2, PACATOC(r13) /* get kernel TOC in r2 */
addi r5, r1, 112
mfctr r4 /* ftrace_caller has moved local addr here */
std r4, 40(r1)
mflr r3 /* ftrace_caller has restored LR from stack */

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@ -41,6 +41,7 @@ _GLOBAL(ftrace_stub)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
_GLOBAL(ftrace_graph_caller)
addi r5, r1, 112
/* load r4 with local address */
ld r4, 128(r1)
subi r4, r4, MCOUNT_INSN_SIZE