From: "Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx> Get the ftrace recursion lock in the generic function_graph_enter() instead of each architecture code. This changes all function_graph tracer callbacks running in non-preemptive state. On x86 and powerpc, this is by default, but on the other architecutres, this will be new. Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> Cc: Florent Revest <revest@xxxxxxxxxxxx> Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx> Cc: bpf <bpf@xxxxxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Alan Maguire <alan.maguire@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Cc: Naveen N Rao <naveen@xxxxxxxxxx> Cc: Madhavan Srinivasan <maddy@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: x86@xxxxxxxxxx Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Link: https://lore.kernel.org/173379653720.973433.18438622234884980494.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> --- arch/powerpc/kernel/trace/ftrace.c | 6 ------ arch/powerpc/kernel/trace/ftrace_64_pg.c | 6 ------ arch/x86/kernel/ftrace.c | 7 ------- kernel/trace/fgraph.c | 8 +++++++- 4 files changed, 7 insertions(+), 20 deletions(-) diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 5ccd791761e8..e41daf2c4a31 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -658,7 +658,6 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) { unsigned long sp = arch_ftrace_regs(fregs)->regs.gpr[1]; - int bit; if (unlikely(ftrace_graph_is_dead())) goto out; @@ -666,14 +665,9 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; - bit = ftrace_test_recursion_trylock(ip, parent_ip); - if (bit < 0) - goto out; - if (!function_graph_enter(parent_ip, ip, 0, (unsigned long *)sp)) parent_ip = ppc_function_entry(return_to_handler); - ftrace_test_recursion_unlock(bit); out: arch_ftrace_regs(fregs)->regs.link = parent_ip; } diff --git a/arch/powerpc/kernel/trace/ftrace_64_pg.c b/arch/powerpc/kernel/trace/ftrace_64_pg.c index 98787376eb87..8fb860b90ae1 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_pg.c +++ b/arch/powerpc/kernel/trace/ftrace_64_pg.c @@ -790,7 +790,6 @@ static unsigned long __prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp) { unsigned long return_hooker; - int bit; if (unlikely(ftrace_graph_is_dead())) goto out; @@ -798,16 +797,11 @@ __prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; - bit = ftrace_test_recursion_trylock(ip, parent); - if (bit < 0) - goto out; - return_hooker = ppc_function_entry(return_to_handler); if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp)) parent = return_hooker; - ftrace_test_recursion_unlock(bit); out: return parent; } diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 4dd0ad6c94d6..33f50c80f481 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -615,7 +615,6 @@ void prepare_ftrace_return(unsigned long ip, unsigned long *parent, unsigned long frame_pointer) { unsigned long return_hooker = (unsigned long)&return_to_handler; - int bit; /* * When resuming from suspend-to-ram, this function can be indirectly @@ -635,14 +634,8 @@ void prepare_ftrace_return(unsigned long ip, unsigned long *parent, if (unlikely(atomic_read(¤t->tracing_graph_pause))) return; - bit = ftrace_test_recursion_trylock(ip, *parent); - if (bit < 0) - return; - if (!function_graph_enter(*parent, ip, frame_pointer, parent)) *parent = return_hooker; - - ftrace_test_recursion_unlock(bit); } #ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index ddedcb50917f..5c68d6109119 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -650,8 +650,13 @@ int function_graph_enter(unsigned long ret, unsigned long func, struct ftrace_graph_ent trace; unsigned long bitmap = 0; int offset; + int bit; int i; + bit = ftrace_test_recursion_trylock(func, ret); + if (bit < 0) + return -EBUSY; + trace.func = func; trace.depth = ++current->curr_ret_depth; @@ -697,12 +702,13 @@ int function_graph_enter(unsigned long ret, unsigned long func, * flag, set that bit always. */ set_bitmap(current, offset, bitmap | BIT(0)); - + ftrace_test_recursion_unlock(bit); return 0; out_ret: current->curr_ret_stack -= FGRAPH_FRAME_OFFSET + 1; out: current->curr_ret_depth--; + ftrace_test_recursion_unlock(bit); return -EBUSY; } -- 2.45.2
