From ddc3d98807dca05ad10f4c76d13019c428302719 Mon Sep 17 00:00:00 2001 From: Jordan Rome Date: Fri, 23 Aug 2024 12:51:01 -0700 Subject: [PATCH] selftests/bpf: Add tests for bpf_copy_from_user_str kfunc. This adds tests for both the happy path and the error path. Signed-off-by: Jordan Rome Link: https://lore.kernel.org/r/20240823195101.3621028-2-linux@jordanrome.com Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/prog_tests/attach_probe.c | 8 ++- .../selftests/bpf/prog_tests/read_vsyscall.c | 1 + .../selftests/bpf/progs/read_vsyscall.c | 9 ++- .../selftests/bpf/progs/test_attach_probe.c | 64 ++++++++++++++++++- 4 files changed, 75 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index 7175af39134f..329c7862b52d 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -283,9 +283,11 @@ static void test_uprobe_sleepable(struct test_attach_probe *skel) trigger_func3(); ASSERT_EQ(skel->bss->uprobe_byname3_sleepable_res, 9, "check_uprobe_byname3_sleepable_res"); - ASSERT_EQ(skel->bss->uprobe_byname3_res, 10, "check_uprobe_byname3_res"); - ASSERT_EQ(skel->bss->uretprobe_byname3_sleepable_res, 11, "check_uretprobe_byname3_sleepable_res"); - ASSERT_EQ(skel->bss->uretprobe_byname3_res, 12, "check_uretprobe_byname3_res"); + ASSERT_EQ(skel->bss->uprobe_byname3_str_sleepable_res, 10, "check_uprobe_byname3_str_sleepable_res"); + ASSERT_EQ(skel->bss->uprobe_byname3_res, 11, "check_uprobe_byname3_res"); + ASSERT_EQ(skel->bss->uretprobe_byname3_sleepable_res, 12, "check_uretprobe_byname3_sleepable_res"); + ASSERT_EQ(skel->bss->uretprobe_byname3_str_sleepable_res, 13, "check_uretprobe_byname3_str_sleepable_res"); + ASSERT_EQ(skel->bss->uretprobe_byname3_res, 14, "check_uretprobe_byname3_res"); } void test_attach_probe(void) diff --git a/tools/testing/selftests/bpf/prog_tests/read_vsyscall.c b/tools/testing/selftests/bpf/prog_tests/read_vsyscall.c index 3405923fe4e6..c7b9ba8b1d06 100644 --- a/tools/testing/selftests/bpf/prog_tests/read_vsyscall.c +++ b/tools/testing/selftests/bpf/prog_tests/read_vsyscall.c @@ -23,6 +23,7 @@ struct read_ret_desc { { .name = "probe_read_user_str", .ret = -EFAULT }, { .name = "copy_from_user", .ret = -EFAULT }, { .name = "copy_from_user_task", .ret = -EFAULT }, + { .name = "copy_from_user_str", .ret = -EFAULT }, }; void test_read_vsyscall(void) diff --git a/tools/testing/selftests/bpf/progs/read_vsyscall.c b/tools/testing/selftests/bpf/progs/read_vsyscall.c index 986f96687ae1..39ebef430059 100644 --- a/tools/testing/selftests/bpf/progs/read_vsyscall.c +++ b/tools/testing/selftests/bpf/progs/read_vsyscall.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (C) 2024. Huawei Technologies Co., Ltd */ +#include "vmlinux.h" #include #include @@ -7,10 +8,15 @@ int target_pid = 0; void *user_ptr = 0; -int read_ret[8]; +int read_ret[9]; char _license[] SEC("license") = "GPL"; +/* + * This is the only kfunc, the others are helpers + */ +int bpf_copy_from_user_str(void *dst, u32, const void *, u64) __weak __ksym; + SEC("fentry/" SYS_PREFIX "sys_nanosleep") int do_probe_read(void *ctx) { @@ -40,6 +46,7 @@ int do_copy_from_user(void *ctx) read_ret[6] = bpf_copy_from_user(buf, sizeof(buf), user_ptr); read_ret[7] = bpf_copy_from_user_task(buf, sizeof(buf), user_ptr, bpf_get_current_task_btf(), 0); + read_ret[8] = bpf_copy_from_user_str((char *)buf, sizeof(buf), user_ptr, 0); return 0; } diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c index 68466a6ad18c..fb79e6cab932 100644 --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -5,8 +5,10 @@ #include #include #include +#include #include "bpf_misc.h" +u32 dynamic_sz = 1; int kprobe2_res = 0; int kretprobe2_res = 0; int uprobe_byname_res = 0; @@ -14,11 +16,15 @@ int uretprobe_byname_res = 0; int uprobe_byname2_res = 0; int uretprobe_byname2_res = 0; int uprobe_byname3_sleepable_res = 0; +int uprobe_byname3_str_sleepable_res = 0; int uprobe_byname3_res = 0; int uretprobe_byname3_sleepable_res = 0; +int uretprobe_byname3_str_sleepable_res = 0; int uretprobe_byname3_res = 0; void *user_ptr = 0; +int bpf_copy_from_user_str(void *dst, u32, const void *, u64) __weak __ksym; + SEC("ksyscall/nanosleep") int BPF_KSYSCALL(handle_kprobe_auto, struct __kernel_timespec *req, struct __kernel_timespec *rem) { @@ -87,11 +93,61 @@ static __always_inline bool verify_sleepable_user_copy(void) return bpf_strncmp(data, sizeof(data), "test_data") == 0; } +static __always_inline bool verify_sleepable_user_copy_str(void) +{ + int ret; + char data_long[20]; + char data_long_pad[20]; + char data_long_err[20]; + char data_short[4]; + char data_short_pad[4]; + + ret = bpf_copy_from_user_str(data_short, sizeof(data_short), user_ptr, 0); + + if (bpf_strncmp(data_short, 4, "tes\0") != 0 || ret != 4) + return false; + + ret = bpf_copy_from_user_str(data_short_pad, sizeof(data_short_pad), user_ptr, BPF_F_PAD_ZEROS); + + if (bpf_strncmp(data_short, 4, "tes\0") != 0 || ret != 4) + return false; + + /* Make sure this passes the verifier */ + ret = bpf_copy_from_user_str(data_long, dynamic_sz & sizeof(data_long), user_ptr, 0); + + if (ret != 0) + return false; + + ret = bpf_copy_from_user_str(data_long, sizeof(data_long), user_ptr, 0); + + if (bpf_strncmp(data_long, 10, "test_data\0") != 0 || ret != 10) + return false; + + ret = bpf_copy_from_user_str(data_long_pad, sizeof(data_long_pad), user_ptr, BPF_F_PAD_ZEROS); + + if (bpf_strncmp(data_long_pad, 10, "test_data\0") != 0 || ret != 10 || data_long_pad[19] != '\0') + return false; + + ret = bpf_copy_from_user_str(data_long_err, sizeof(data_long_err), (void *)data_long, BPF_F_PAD_ZEROS); + + if (ret > 0 || data_long_err[19] != '\0') + return false; + + ret = bpf_copy_from_user_str(data_long, sizeof(data_long), user_ptr, 2); + + if (ret != -EINVAL) + return false; + + return true; +} + SEC("uprobe.s//proc/self/exe:trigger_func3") int handle_uprobe_byname3_sleepable(struct pt_regs *ctx) { if (verify_sleepable_user_copy()) uprobe_byname3_sleepable_res = 9; + if (verify_sleepable_user_copy_str()) + uprobe_byname3_str_sleepable_res = 10; return 0; } @@ -102,7 +158,7 @@ int handle_uprobe_byname3_sleepable(struct pt_regs *ctx) SEC("uprobe//proc/self/exe:trigger_func3") int handle_uprobe_byname3(struct pt_regs *ctx) { - uprobe_byname3_res = 10; + uprobe_byname3_res = 11; return 0; } @@ -110,14 +166,16 @@ SEC("uretprobe.s//proc/self/exe:trigger_func3") int handle_uretprobe_byname3_sleepable(struct pt_regs *ctx) { if (verify_sleepable_user_copy()) - uretprobe_byname3_sleepable_res = 11; + uretprobe_byname3_sleepable_res = 12; + if (verify_sleepable_user_copy_str()) + uretprobe_byname3_str_sleepable_res = 13; return 0; } SEC("uretprobe//proc/self/exe:trigger_func3") int handle_uretprobe_byname3(struct pt_regs *ctx) { - uretprobe_byname3_res = 12; + uretprobe_byname3_res = 14; return 0; }