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function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it

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All architectures that implement function graph also implements
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR. Remove it, as it is no longer a
differentiator.

Link: https://lore.kernel.org/linux-trace-kernel/20240611031737.982047614@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Google) 2024-06-10 23:09:36 -04:00
parent 29c1c24a27
commit 5f7fb89a11
10 changed files with 1 additions and 68 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
Documentation/trace/ftrace-design.rst
View File

@ -217,18 +217,6 @@ along to ftrace_push_return_trace() instead of a stub value of 0.
Similarly, when you call ftrace_return_to_handler(), pass it the frame pointer.
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
--------------------------------
An arch may pass in a pointer to the return address on the stack. This
prevents potential stack unwinding issues where the unwinder gets out of
sync with ret_stack and the wrong addresses are reported by
ftrace_graph_ret_addr().
Adding support for it is easy: just define the macro in asm/ftrace.h and
pass the return address pointer as the 'retp' argument to
ftrace_push_return_trace().
HAVE_SYSCALL_TRACEPOINTS
------------------------

11
arch/arm64/include/asm/ftrace.h
View File

@ -12,17 +12,6 @@
#define HAVE_FUNCTION_GRAPH_FP_TEST
/*
* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR means that the architecture can provide a
* "return address pointer" which can be used to uniquely identify a return
* address which has been overwritten.
*
* On arm64 we use the address of the caller's frame record, which remains the
* same for the lifetime of the instrumented function, unlike the return
* address in the LR.
*/
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
#define ARCH_SUPPORTS_FTRACE_OPS 1
#else

2
arch/csky/include/asm/ftrace.h
View File

@ -7,8 +7,6 @@
#define HAVE_FUNCTION_GRAPH_FP_TEST
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#define ARCH_SUPPORTS_FTRACE_OPS 1
#define MCOUNT_ADDR ((unsigned long)_mcount)

1
arch/loongarch/include/asm/ftrace.h
View File

@ -28,7 +28,6 @@ struct dyn_ftrace;
struct dyn_arch_ftrace { };
#define ARCH_SUPPORTS_FTRACE_OPS 1
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#define ftrace_init_nop ftrace_init_nop
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);

2
arch/powerpc/include/asm/ftrace.h
View File

@ -8,8 +8,6 @@
#define MCOUNT_ADDR ((unsigned long)(_mcount))
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
/* Ignore unused weak functions which will have larger offsets */
#if defined(CONFIG_MPROFILE_KERNEL) || defined(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)
#define FTRACE_MCOUNT_MAX_OFFSET 16

1
arch/riscv/include/asm/ftrace.h
View File

@ -11,7 +11,6 @@
#if defined(CONFIG_FUNCTION_GRAPH_TRACER) && defined(CONFIG_FRAME_POINTER)
#define HAVE_FUNCTION_GRAPH_FP_TEST
#endif
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#define ARCH_SUPPORTS_FTRACE_OPS 1
#ifndef __ASSEMBLY__

1
arch/s390/include/asm/ftrace.h
View File

@ -2,7 +2,6 @@
#ifndef _ASM_S390_FTRACE_H
#define _ASM_S390_FTRACE_H
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#define ARCH_SUPPORTS_FTRACE_OPS 1
#define MCOUNT_INSN_SIZE 6

2
arch/x86/include/asm/ftrace.h
View File

@ -20,8 +20,6 @@
#define ARCH_SUPPORTS_FTRACE_OPS 1
#endif
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#ifndef __ASSEMBLY__
extern void __fentry__(void);

2
include/linux/ftrace.h
View File

@ -1071,9 +1071,7 @@ struct ftrace_ret_stack {
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
unsigned long fp;
#endif
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
unsigned long *retp;
#endif
};
/*

35
kernel/trace/fgraph.c
View File

@ -593,9 +593,7 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func,
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
ret_stack->fp = frame_pointer;
#endif
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
ret_stack->retp = retp;
#endif
return offset;
}
@ -887,10 +885,8 @@ ftrace_graph_get_ret_stack(struct task_struct *task, int idx)
* will be assigned that location so that if called again, it will continue
* where it left off.
*
* @retp is a pointer to the return address on the stack. It's ignored if
* the arch doesn't have HAVE_FUNCTION_GRAPH_RET_ADDR_PTR defined.
* @retp is a pointer to the return address on the stack.
*/
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp)
{
@ -926,35 +922,6 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
return ret;
}
#else /* !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp)
{
struct ftrace_ret_stack *ret_stack;
unsigned long return_handler = (unsigned long)dereference_kernel_function_descriptor(return_to_handler);
int offset = task->curr_ret_stack;
int i;
if (ret != return_handler)
return ret;
if (!idx)
return ret;
i = *idx;
do {
ret_stack = get_ret_stack(task, offset, &offset);
if (ret_stack && ret_stack->ret == return_handler)
continue;
i--;
} while (i >= 0 && ret_stack);
if (ret_stack)
return ret_stack->ret;
return ret;
}
#endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
static struct ftrace_ops graph_ops = {
.func = ftrace_graph_func,