From: Maxwell Bland <mbland@motorola.com>
To: "open list:BPF [GENERAL] (Safe Dynamic Programs and Tools)"
<bpf@vger.kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>, Zi Shen Lim <zlim.lnx@gmail.com>,
Mark Rutland <mark.rutland@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Mark Brown <broonie@kernel.org>,
linux-arm-kernel@lists.infradead.org,
open list <linux-kernel@vger.kernel.org>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Puranjay Mohan <puranjay12@gmail.com>
Subject: [PATCH bpf-next v4 1/3] cfi: add C CFI type macro
Date: Mon, 13 May 2024 09:10:36 -0500 [thread overview]
Message-ID: <6hawcu7saygxwndxkzmhn7qt5vgqjha3goodr7p7v3e6k2erpi@hj775dv6h6xv> (raw)
In-Reply-To: <wtb6czzpvtqq23t4g6hf7on257dtxzdb4fa4nuq3dtq32odmli@xoyyrtthafar>
From: Mark Rutland <mark.rutland@arm.com>
Currently x86 and riscv open-code 4 instances of the same logic to
define a u32 variable with the KCFI typeid of a given function.
Replace the duplicate logic with a common macro.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
Minor fix of authorship attribution by adding "From:" field!
arch/riscv/kernel/cfi.c | 34 ++--------------------------------
arch/x86/kernel/alternative.c | 35 +++--------------------------------
include/linux/cfi_types.h | 23 +++++++++++++++++++++++
3 files changed, 28 insertions(+), 64 deletions(-)
diff --git a/arch/riscv/kernel/cfi.c b/arch/riscv/kernel/cfi.c
index 64bdd3e1ab8c..b78a6f41df22 100644
--- a/arch/riscv/kernel/cfi.c
+++ b/arch/riscv/kernel/cfi.c
@@ -82,41 +82,11 @@ struct bpf_insn;
/* Must match bpf_func_t / DEFINE_BPF_PROG_RUN() */
extern unsigned int __bpf_prog_runX(const void *ctx,
const struct bpf_insn *insn);
-
-/*
- * Force a reference to the external symbol so the compiler generates
- * __kcfi_typid.
- */
-__ADDRESSABLE(__bpf_prog_runX);
-
-/* u32 __ro_after_init cfi_bpf_hash = __kcfi_typeid___bpf_prog_runX; */
-asm (
-" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
-" .type cfi_bpf_hash,@object \n"
-" .globl cfi_bpf_hash \n"
-" .p2align 2, 0x0 \n"
-"cfi_bpf_hash: \n"
-" .word __kcfi_typeid___bpf_prog_runX \n"
-" .size cfi_bpf_hash, 4 \n"
-" .popsection \n"
-);
+DEFINE_CFI_TYPE(cfi_bpf_hash, __bpf_prog_runX);
/* Must match bpf_callback_t */
extern u64 __bpf_callback_fn(u64, u64, u64, u64, u64);
-
-__ADDRESSABLE(__bpf_callback_fn);
-
-/* u32 __ro_after_init cfi_bpf_subprog_hash = __kcfi_typeid___bpf_callback_fn; */
-asm (
-" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
-" .type cfi_bpf_subprog_hash,@object \n"
-" .globl cfi_bpf_subprog_hash \n"
-" .p2align 2, 0x0 \n"
-"cfi_bpf_subprog_hash: \n"
-" .word __kcfi_typeid___bpf_callback_fn \n"
-" .size cfi_bpf_subprog_hash, 4 \n"
-" .popsection \n"
-);
+DEFINE_CFI_TYPE(cfi_bpf_subprog_hash, __bpf_callback_fn);
u32 cfi_get_func_hash(void *func)
{
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 45a280f2161c..a822699a40dd 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0-only
#define pr_fmt(fmt) "SMP alternatives: " fmt
+#include <linux/cfi_types.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/perf_event.h>
@@ -918,41 +919,11 @@ struct bpf_insn;
/* Must match bpf_func_t / DEFINE_BPF_PROG_RUN() */
extern unsigned int __bpf_prog_runX(const void *ctx,
const struct bpf_insn *insn);
-
-/*
- * Force a reference to the external symbol so the compiler generates
- * __kcfi_typid.
- */
-__ADDRESSABLE(__bpf_prog_runX);
-
-/* u32 __ro_after_init cfi_bpf_hash = __kcfi_typeid___bpf_prog_runX; */
-asm (
-" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
-" .type cfi_bpf_hash,@object \n"
-" .globl cfi_bpf_hash \n"
-" .p2align 2, 0x0 \n"
-"cfi_bpf_hash: \n"
-" .long __kcfi_typeid___bpf_prog_runX \n"
-" .size cfi_bpf_hash, 4 \n"
-" .popsection \n"
-);
+DEFINE_CFI_TYPE(cfi_bpf_hash, __bpf_prog_runX);
/* Must match bpf_callback_t */
extern u64 __bpf_callback_fn(u64, u64, u64, u64, u64);
-
-__ADDRESSABLE(__bpf_callback_fn);
-
-/* u32 __ro_after_init cfi_bpf_subprog_hash = __kcfi_typeid___bpf_callback_fn; */
-asm (
-" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
-" .type cfi_bpf_subprog_hash,@object \n"
-" .globl cfi_bpf_subprog_hash \n"
-" .p2align 2, 0x0 \n"
-"cfi_bpf_subprog_hash: \n"
-" .long __kcfi_typeid___bpf_callback_fn \n"
-" .size cfi_bpf_subprog_hash, 4 \n"
-" .popsection \n"
-);
+DEFINE_CFI_TYPE(cfi_bpf_subprog_hash, __bpf_callback_fn);
u32 cfi_get_func_hash(void *func)
{
diff --git a/include/linux/cfi_types.h b/include/linux/cfi_types.h
index 6b8713675765..f510e62ca8b1 100644
--- a/include/linux/cfi_types.h
+++ b/include/linux/cfi_types.h
@@ -41,5 +41,28 @@
SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
#endif
+#else /* __ASSEMBLY__ */
+
+#ifdef CONFIG_CFI_CLANG
+#define DEFINE_CFI_TYPE(name, func) \
+ /* \
+ * Force a reference to the function so the compiler generates \
+ * __kcfi_typeid_<func>. \
+ */ \
+ __ADDRESSABLE(func); \
+ /* u32 name = __kcfi_typeid_<func> */ \
+ extern u32 name; \
+ asm ( \
+ " .pushsection .data..ro_after_init,\"aw\",@progbits \n" \
+ " .type " #name ",@object \n" \
+ " .globl " #name " \n" \
+ " .p2align 2, 0x0 \n" \
+ #name ": \n" \
+ " .long __kcfi_typeid_" #func " \n" \
+ " .size " #name ", 4 \n" \
+ " .popsection \n" \
+ );
+#endif
+
#endif /* __ASSEMBLY__ */
#endif /* _LINUX_CFI_TYPES_H */
--
2.34.1
next prev parent reply other threads:[~2024-05-13 14:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-13 14:08 [PATCH bpf-next v4 0/3] Support kCFI + BPF on arm64 Maxwell Bland
2024-05-13 14:10 ` Maxwell Bland [this message]
2024-05-13 14:12 ` [PATCH bpf-next v4 2/3] arm64/cfi,bpf: " Maxwell Bland
2024-05-13 16:39 ` Puranjay Mohan
2024-05-15 16:05 ` Maxwell Bland
2024-05-13 14:14 ` [PATCH bpf-next v4 3/3] arm64/cfi,bpf: Use DEFINE_CFI_TYPE in arm64 Maxwell Bland
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