From 370011a27028d6f05e598ed6211a0ca2dc0213f7 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Thu, 5 Sep 2019 23:50:29 +0530 Subject: [PATCH] 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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/0224f2d0971b069c678e2ff678cfc2cd1e114cfe.1567707399.git.naveen.n.rao@linux.vnet.ibm.com --- arch/powerpc/include/asm/asm-prototypes.h | 3 ++- arch/powerpc/include/asm/ftrace.h | 2 ++ arch/powerpc/kernel/stacktrace.c | 2 +- arch/powerpc/kernel/trace/ftrace.c | 5 +++-- arch/powerpc/kernel/trace/ftrace_32.S | 1 + arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 1 + arch/powerpc/kernel/trace/ftrace_64_pg.S | 1 + 7 files changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h index 49196d3..8561498 100644 --- a/arch/powerpc/include/asm/asm-prototypes.h +++ b/arch/powerpc/include/asm/asm-prototypes.h @@ -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); diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index 3dfb80b..f54a08a 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -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 */ diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c index 1e22769..e2a46cf 100644 --- a/arch/powerpc/kernel/stacktrace.c +++ b/arch/powerpc/kernel/stacktrace.c @@ -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 diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index be1ca98..7ea0ca0 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -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; diff --git a/arch/powerpc/kernel/trace/ftrace_32.S b/arch/powerpc/kernel/trace/ftrace_32.S index 183f608..e023ae5 100644 --- a/arch/powerpc/kernel/trace/ftrace_32.S +++ b/arch/powerpc/kernel/trace/ftrace_32.S @@ -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 diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S index 74acbf1..f9fd5f7 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S +++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S @@ -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 */ diff --git a/arch/powerpc/kernel/trace/ftrace_64_pg.S b/arch/powerpc/kernel/trace/ftrace_64_pg.S index e41a7d1..6708e24 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_pg.S +++ b/arch/powerpc/kernel/trace/ftrace_64_pg.S @@ -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 -- 2.7.4