[PATCH] riscv: Adjust dependencies of HAVE_DYNAMIC_FTRACE selection
Nathan Chancellor
nathan at kernel.org
Tue Apr 4 13:34:21 PDT 2023
When building allmodconfig with clang and its integrated assembler and
linking with a version of GNU ld prior to 2.36, the following link error
occurs:
riscv64-linux-gnu-ld: .init.data has both ordered [`__patchable_function_entries' in init/main.o] and unordered [`.init_array.0' in kernel/trace/trace_benchmark.o] sections
riscv64-linux-gnu-ld: final link failed: bad value
This is the same error addressed by commit 45bd8951806e ("arm64: Improve
HAVE_DYNAMIC_FTRACE_WITH_REGS selection for clang") for arm64. See that
changelog for a full description of why this error occurs with this
combination of tools.
In a similar manner as that change, restrict the
CONFIG_HAVE_DYNAMIC_FTRACE selection to combinations of tools known to
work so that there are no errors.
Link: https://github.com/ClangBuiltLinux/linux/issues/1817
Signed-off-by: Nathan Chancellor <nathan at kernel.org>
---
arch/riscv/Kconfig | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index eb7f29a412f8..4b82838ac870 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -136,12 +136,23 @@ config RISCV
select TRACE_IRQFLAGS_SUPPORT
select UACCESS_MEMCPY if !MMU
select ZONE_DMA32 if 64BIT
- select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
+ select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
+config CLANG_SUPPORTS_DYNAMIC_FTRACE
+ def_bool CC_IS_CLANG
+ # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e
+ depends on CLANG_VERSION >= 130000
+ # https://github.com/ClangBuiltLinux/linux/issues/1817
+ depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
+
+config GCC_SUPPORTS_DYNAMIC_FTRACE
+ def_bool CC_IS_GCC
+ depends on $(cc-option,-fpatchable-function-entry=8)
+
config ARCH_MMAP_RND_BITS_MIN
default 18 if 64BIT
default 8
---
base-commit: 4622f159098e098611f393cccf73d52b007e70bc
change-id: 20230404-riscv-dynamic-ftrace-checks-clang-6781b41c41ff
Best regards,
--
Nathan Chancellor <nathan at kernel.org>
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