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Message-Id: <1649195156-9465-3-git-send-email-alan.maguire@oracle.com>
Date: Tue, 5 Apr 2022 22:45:56 +0100
From: Alan Maguire <alan.maguire@...cle.com>
To: andrii@...nel.org, daniel@...earbox.net, ast@...nel.org
Cc: kafai@...com, songliubraving@...com, yhs@...com,
john.fastabend@...il.com, kpsingh@...nel.org, bpf@...r.kernel.org,
netdev@...r.kernel.org, Alan Maguire <alan.maguire@...cle.com>
Subject: [PATCH bpf-next 2/2] selftests/bpf: uprobe tests should verify param/return values
uprobe/uretprobe tests don't do any validation of arguments/return values,
and without this we can't be sure we are attached to the right function,
or that we are indeed attached to a uprobe or uretprobe. To fix this
validate argument and return value for auto-attached functions.
Suggested-by: Andrii Nakryiko <andrii@...nel.org>
Signed-off-by: Alan Maguire <alan.maguire@...cle.com>
---
.../selftests/bpf/prog_tests/uprobe_autoattach.c | 16 ++++++++++----
.../selftests/bpf/progs/test_uprobe_autoattach.c | 25 +++++++++++++++-------
2 files changed, 29 insertions(+), 12 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c
index 03b15d6..ff85f1f 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c
@@ -5,14 +5,16 @@
#include "test_uprobe_autoattach.skel.h"
/* uprobe attach point */
-static void autoattach_trigger_func(void)
+static noinline int autoattach_trigger_func(int arg)
{
- asm volatile ("");
+ return arg + 1;
}
void test_uprobe_autoattach(void)
{
struct test_uprobe_autoattach *skel;
+ int trigger_val = 100;
+ size_t malloc_sz = 1;
char *mem;
skel = test_uprobe_autoattach__open_and_load();
@@ -22,12 +24,18 @@ void test_uprobe_autoattach(void)
if (!ASSERT_OK(test_uprobe_autoattach__attach(skel), "skel_attach"))
goto cleanup;
+ skel->bss->uprobe_byname_parm1 = trigger_val;
+ skel->bss->uretprobe_byname_rc = trigger_val + 1;
+ skel->bss->uprobe_byname2_parm1 = malloc_sz;
+ skel->bss->uretprobe_byname2_rc = getpid();
+
/* trigger & validate uprobe & uretprobe */
- autoattach_trigger_func();
+ (void) autoattach_trigger_func(trigger_val);
/* trigger & validate shared library u[ret]probes attached by name */
- mem = malloc(1);
+ mem = malloc(malloc_sz);
free(mem);
+ (void) getpid();
ASSERT_EQ(skel->bss->uprobe_byname_res, 1, "check_uprobe_byname_res");
ASSERT_EQ(skel->bss->uretprobe_byname_res, 2, "check_uretprobe_byname_res");
diff --git a/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c b/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c
index b442fb5..db104bd 100644
--- a/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c
+++ b/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c
@@ -1,15 +1,20 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022, Oracle and/or its affiliates. */
-#include <linux/ptrace.h>
-#include <linux/bpf.h>
+#include "vmlinux.h"
+
+#include <bpf/bpf_core_read.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
+int uprobe_byname_parm1 = 0;
int uprobe_byname_res = 0;
+int uretprobe_byname_rc = 0;
int uretprobe_byname_res = 0;
+size_t uprobe_byname2_parm1 = 0;
int uprobe_byname2_res = 0;
-int uretprobe_byname2_res = 0;
+int uretprobe_byname2_rc = 0;
+pid_t uretprobe_byname2_res = 0;
/* This program cannot auto-attach, but that should not stop other
* programs from attaching.
@@ -23,14 +28,16 @@ int handle_uprobe_noautoattach(struct pt_regs *ctx)
SEC("uprobe//proc/self/exe:autoattach_trigger_func")
int handle_uprobe_byname(struct pt_regs *ctx)
{
- uprobe_byname_res = 1;
+ if (PT_REGS_PARM1_CORE(ctx) == uprobe_byname_parm1)
+ uprobe_byname_res = 1;
return 0;
}
SEC("uretprobe//proc/self/exe:autoattach_trigger_func")
int handle_uretprobe_byname(struct pt_regs *ctx)
{
- uretprobe_byname_res = 2;
+ if (PT_REGS_RC_CORE(ctx) == uretprobe_byname_rc)
+ uretprobe_byname_res = 2;
return 0;
}
@@ -38,14 +45,16 @@ int handle_uretprobe_byname(struct pt_regs *ctx)
SEC("uprobe/libc.so.6:malloc")
int handle_uprobe_byname2(struct pt_regs *ctx)
{
- uprobe_byname2_res = 3;
+ if (PT_REGS_PARM1_CORE(ctx) == uprobe_byname2_parm1)
+ uprobe_byname2_res = 3;
return 0;
}
-SEC("uretprobe/libc.so.6:free")
+SEC("uretprobe/libc.so.6:getpid")
int handle_uretprobe_byname2(struct pt_regs *ctx)
{
- uretprobe_byname2_res = 4;
+ if (PT_REGS_RC_CORE(ctx) == uretprobe_byname2_rc)
+ uretprobe_byname2_res = 4;
return 0;
}
--
1.8.3.1
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