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>
---
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 89de61243272..933d0c13a0d8 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>
@@ -901,41 +902,11 @@ 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 */
--
2.39.2On Mon, Jun 10, 2024 at 01:06:33PM -0500, Maxwell Bland wrote: > 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> This patch is missing your signed-off-by (the same with the second patch). Since you are submitting it, you should also add yours in addition to the author's s-o-b. -- Catalin
On Tue, Jun 11, 2024 at 05:30:28PM GMT, Catalin Marinas wrote: > This patch is missing your signed-off-by (the same with the second > patch). Since you are submitting it, you should also add yours in > addition to the author's s-o-b. I see, thank you Catalin. I have also fixed the compiler errors. Usually I would wait a week to resubmit, but since v5 took me a while to get out the door, I've pushed a new version here: https://lore.kernel.org/all/illfkwuxwq3adca2h4shibz2xub62kku3g2wte4sqp7xj7cwkb@ckn3qg7zxjuv/ Maxwell
Hi Maxwell,
kernel test robot noticed the following build errors:
[auto build test ERROR on bpf-next/master]
url: https://github.com/intel-lab-lkp/linux/commits/Maxwell-Bland/arm64-cfi-bpf-Support-kCFI-BPF-on-arm64/20240611-021203
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/r/cwhnmpn5yvg6ma7mvjviy4p7z6gdoba57daeprpc4zcokfhpv2%4044gvdmcfuspt
patch subject: [PATCH bpf-next v5 1/3] cfi: add C CFI type macro
config: riscv-allmodconfig (https://download.01.org/0day-ci/archive/20240611/202406111716.SluzXu9X-lkp@intel.com/config)
compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project 4403cdbaf01379de96f8d0d6ea4f51a085e37766)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240611/202406111716.SluzXu9X-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202406111716.SluzXu9X-lkp@intel.com/
All errors (new ones prefixed by >>):
>> arch/riscv/kernel/cfi.c:85:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
85 | DEFINE_CFI_TYPE(cfi_bpf_hash, __bpf_prog_runX);
| ^
| int
>> arch/riscv/kernel/cfi.c:85:17: error: a parameter list without types is only allowed in a function definition
85 | DEFINE_CFI_TYPE(cfi_bpf_hash, __bpf_prog_runX);
| ^
arch/riscv/kernel/cfi.c:89:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
89 | DEFINE_CFI_TYPE(cfi_bpf_subprog_hash, __bpf_callback_fn);
| ^
| int
arch/riscv/kernel/cfi.c:89:17: error: a parameter list without types is only allowed in a function definition
89 | DEFINE_CFI_TYPE(cfi_bpf_subprog_hash, __bpf_callback_fn);
| ^
4 errors generated.
vim +/int +85 arch/riscv/kernel/cfi.c
81
82 /* Must match bpf_func_t / DEFINE_BPF_PROG_RUN() */
83 extern unsigned int __bpf_prog_runX(const void *ctx,
84 const struct bpf_insn *insn);
> 85 DEFINE_CFI_TYPE(cfi_bpf_hash, __bpf_prog_runX);
86
--
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