struct pt_regs is not exported to userspace on all archs. arm64 and s390 export "user_pt_regs" instead, which causes build failure at the moment:
progs/test_task_pt_regs.c:8:16: error: variable has incomplete type 'struct pt_regs' struct pt_regs current_regs = {};
Instead of using pt_regs from ptrace.h, use the larger kernel struct from vmlinux.h directly. Since the test runner task_pt_regs.c does not have access to the kernel struct definition, copy it into a char array.
Fixes: 576d47bb1a92 ("bpf: selftests: Add bpf_task_pt_regs() selftest") Suggested-by: Andrii Nakryiko andrii.nakryiko@gmail.com Signed-off-by: Jean-Philippe Brucker jean-philippe@linaro.org --- v2: Work on struct pt_regs from vmlinux.h v1: https://lore.kernel.org/bpf/20210902090925.2010528-1-jean-philippe@linaro.or... --- .../selftests/bpf/prog_tests/task_pt_regs.c | 1 - .../selftests/bpf/progs/test_task_pt_regs.c | 19 +++++++++++++------ 2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/task_pt_regs.c b/tools/testing/selftests/bpf/prog_tests/task_pt_regs.c index 53f0e0fa1a53..37c20b5ffa70 100644 --- a/tools/testing/selftests/bpf/prog_tests/task_pt_regs.c +++ b/tools/testing/selftests/bpf/prog_tests/task_pt_regs.c @@ -1,7 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #define _GNU_SOURCE #include <test_progs.h> -#include <linux/ptrace.h> #include "test_task_pt_regs.skel.h"
void test_task_pt_regs(void) diff --git a/tools/testing/selftests/bpf/progs/test_task_pt_regs.c b/tools/testing/selftests/bpf/progs/test_task_pt_regs.c index 6c059f1cfa1b..e6cb09259408 100644 --- a/tools/testing/selftests/bpf/progs/test_task_pt_regs.c +++ b/tools/testing/selftests/bpf/progs/test_task_pt_regs.c @@ -1,12 +1,17 @@ // SPDX-License-Identifier: GPL-2.0
-#include <linux/ptrace.h> -#include <linux/bpf.h> +#include "vmlinux.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h>
-struct pt_regs current_regs = {}; -struct pt_regs ctx_regs = {}; +#define PT_REGS_SIZE sizeof(struct pt_regs) + +/* + * The kernel struct pt_regs isn't exported in its entirety to userspace. + * Pass it as an array to task_pt_regs.c + */ +char current_regs[PT_REGS_SIZE] = {}; +char ctx_regs[PT_REGS_SIZE] = {}; int uprobe_res = 0;
SEC("uprobe/trigger_func") @@ -17,8 +22,10 @@ int handle_uprobe(struct pt_regs *ctx)
current = bpf_get_current_task_btf(); regs = (struct pt_regs *) bpf_task_pt_regs(current); - __builtin_memcpy(¤t_regs, regs, sizeof(*regs)); - __builtin_memcpy(&ctx_regs, ctx, sizeof(*ctx)); + if (bpf_probe_read_kernel(current_regs, PT_REGS_SIZE, regs)) + return 0; + if (bpf_probe_read_kernel(ctx_regs, PT_REGS_SIZE, ctx)) + return 0;
/* Prove that uprobe was run */ uprobe_res = 1;
On Mon, 2021-09-06 at 17:36 +0100, Jean-Philippe Brucker wrote:
struct pt_regs is not exported to userspace on all archs. arm64 and s390 export "user_pt_regs" instead, which causes build failure at the moment:
progs/test_task_pt_regs.c:8:16: error: variable has incomplete type 'struct pt_regs' struct pt_regs current_regs = {};
Instead of using pt_regs from ptrace.h, use the larger kernel struct from vmlinux.h directly. Since the test runner task_pt_regs.c does not have access to the kernel struct definition, copy it into a char array.
Fixes: 576d47bb1a92 ("bpf: selftests: Add bpf_task_pt_regs() selftest") Suggested-by: Andrii Nakryiko andrii.nakryiko@gmail.com Signed-off-by: Jean-Philippe Brucker jean-philippe@linaro.org
v2: Work on struct pt_regs from vmlinux.h v1: https://lore.kernel.org/bpf/20210902090925.2010528-1-jean-philippe@linaro.or...
.../selftests/bpf/prog_tests/task_pt_regs.c | 1 - .../selftests/bpf/progs/test_task_pt_regs.c | 19 +++++++++++++------ 2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/task_pt_regs.c b/tools/testing/selftests/bpf/prog_tests/task_pt_regs.c index 53f0e0fa1a53..37c20b5ffa70 100644 --- a/tools/testing/selftests/bpf/prog_tests/task_pt_regs.c +++ b/tools/testing/selftests/bpf/prog_tests/task_pt_regs.c @@ -1,7 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #define _GNU_SOURCE #include <test_progs.h> -#include <linux/ptrace.h> #include "test_task_pt_regs.skel.h" void test_task_pt_regs(void) diff --git a/tools/testing/selftests/bpf/progs/test_task_pt_regs.c b/tools/testing/selftests/bpf/progs/test_task_pt_regs.c index 6c059f1cfa1b..e6cb09259408 100644 --- a/tools/testing/selftests/bpf/progs/test_task_pt_regs.c +++ b/tools/testing/selftests/bpf/progs/test_task_pt_regs.c @@ -1,12 +1,17 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/ptrace.h> -#include <linux/bpf.h> +#include "vmlinux.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> -struct pt_regs current_regs = {}; -struct pt_regs ctx_regs = {}; +#define PT_REGS_SIZE sizeof(struct pt_regs)
+/*
- The kernel struct pt_regs isn't exported in its entirety to
userspace.
- Pass it as an array to task_pt_regs.c
- */
+char current_regs[PT_REGS_SIZE] = {}; +char ctx_regs[PT_REGS_SIZE] = {}; int uprobe_res = 0; SEC("uprobe/trigger_func") @@ -17,8 +22,10 @@ int handle_uprobe(struct pt_regs *ctx) current = bpf_get_current_task_btf(); regs = (struct pt_regs *) bpf_task_pt_regs(current); - __builtin_memcpy(¤t_regs, regs, sizeof(*regs)); - __builtin_memcpy(&ctx_regs, ctx, sizeof(*ctx)); + if (bpf_probe_read_kernel(current_regs, PT_REGS_SIZE, regs)) + return 0; + if (bpf_probe_read_kernel(ctx_regs, PT_REGS_SIZE, ctx)) + return 0; /* Prove that uprobe was run */ uprobe_res = 1;
I've tested this patch on s390 and it does indeed fix the build issue. Thanks!
Tested-by: Ilya Leoshkevich iii@linux.ibm.com Acked-by: Ilya Leoshkevich iii@linux.ibm.com
Hello:
This patch was applied to bpf/bpf.git (refs/heads/master):
On Mon, 6 Sep 2021 17:36:38 +0100 you wrote:
struct pt_regs is not exported to userspace on all archs. arm64 and s390 export "user_pt_regs" instead, which causes build failure at the moment:
progs/test_task_pt_regs.c:8:16: error: variable has incomplete type 'struct pt_regs' struct pt_regs current_regs = {};
Instead of using pt_regs from ptrace.h, use the larger kernel struct from vmlinux.h directly. Since the test runner task_pt_regs.c does not have access to the kernel struct definition, copy it into a char array.
[...]
Here is the summary with links: - [bpf-next,v2] selftests/bpf: Fix build of task_pt_regs test for arm64 https://git.kernel.org/bpf/bpf/c/3a029e1f3d6e
You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
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