This is a note to let you know that I've just added the patch titled
powerpc/bpf: Fix use of user_pt_regs in uapi
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-bpf-fix-use-of-user_pt_regs-in-uapi.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b21bd5a4b130f8370861478d2880985daace5913 Mon Sep 17 00:00:00 2001
From: "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Date: Tue, 28 Jun 2022 00:41:19 +0530
Subject: powerpc/bpf: Fix use of user_pt_regs in uapi
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From: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
commit b21bd5a4b130f8370861478d2880985daace5913 upstream.
Trying to build a .c file that includes <linux/bpf_perf_event.h>:
$ cat test_bpf_headers.c
#include <linux/bpf_perf_event.h>
throws the below error:
/usr/include/linux/bpf_perf_event.h:14:28: error: field ‘regs’ has incomplete type
14 | bpf_user_pt_regs_t regs;
| ^~~~
This is because we typedef bpf_user_pt_regs_t to 'struct user_pt_regs'
in arch/powerpc/include/uaps/asm/bpf_perf_event.h, but 'struct
user_pt_regs' is not exposed to userspace.
Powerpc has both pt_regs and user_pt_regs structures. However, unlike
arm64 and s390, we expose user_pt_regs to userspace as just 'pt_regs'.
As such, we should typedef bpf_user_pt_regs_t to 'struct pt_regs' for
userspace.
Within the kernel though, we want to typedef bpf_user_pt_regs_t to
'struct user_pt_regs'.
Remove arch/powerpc/include/uapi/asm/bpf_perf_event.h so that the
uapi/asm-generic version of the header is exposed to userspace.
Introduce arch/powerpc/include/asm/bpf_perf_event.h so that we can
typedef bpf_user_pt_regs_t to 'struct user_pt_regs' for use within the
kernel.
Note that this was not showing up with the bpf selftest build since
tools/include/uapi/asm/bpf_perf_event.h didn't include the powerpc
variant.
Fixes: a6460b03f945ee ("powerpc/bpf: Fix broken uapi for BPF_PROG_TYPE_PERF_EVENT")
Cc: stable@xxxxxxxxxxxxxxx # v4.20+
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
[mpe: Use typical naming for header include guard]
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220627191119.142867-1-naveen.n.rao@xxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/bpf_perf_event.h | 9 +++++++++
arch/powerpc/include/uapi/asm/bpf_perf_event.h | 9 ---------
2 files changed, 9 insertions(+), 9 deletions(-)
create mode 100644 arch/powerpc/include/asm/bpf_perf_event.h
delete mode 100644 arch/powerpc/include/uapi/asm/bpf_perf_event.h
--- /dev/null
+++ b/arch/powerpc/include/asm/bpf_perf_event.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_BPF_PERF_EVENT_H
+#define _ASM_POWERPC_BPF_PERF_EVENT_H
+
+#include <asm/ptrace.h>
+
+typedef struct user_pt_regs bpf_user_pt_regs_t;
+
+#endif /* _ASM_POWERPC_BPF_PERF_EVENT_H */
--- a/arch/powerpc/include/uapi/asm/bpf_perf_event.h
+++ /dev/null
@@ -1,9 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
-#define _UAPI__ASM_BPF_PERF_EVENT_H__
-
-#include <asm/ptrace.h>
-
-typedef struct user_pt_regs bpf_user_pt_regs_t;
-
-#endif /* _UAPI__ASM_BPF_PERF_EVENT_H__ */
Patches currently in stable-queue which might be from naveen.n.rao@xxxxxxxxxxxxxxxxxx are
queue-5.10/powerpc-bpf-fix-use-of-user_pt_regs-in-uapi.patch
