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authorPalmer Dabbelt <palmer@rivosinc.com>2024-01-17 18:08:30 -0800
committerPalmer Dabbelt <palmer@rivosinc.com>2024-01-17 18:08:30 -0800
commit448857ec53a47718b50cdb38b9380660b3f84b20 (patch)
treea32b9261dbe9a3db2ae962a6d4027b7c54bb9d95
parentc640868491105d53899f9f8e613acd4aa06cef68 (diff)
parenta4426641f00cd2c293c91e881ab31faaf76b20fb (diff)
Merge patch series "RISC-V: Disable DWARF5 with known broken LLVM versions"
Nathan Chancellor <nathan@kernel.org> says: This series disables DWARF5 for LLVM versions where it is known to be broken due to linker relaxation. * b4-shazam-merge: lib/Kconfig.debug: Update AS_HAS_NON_CONST_LEB128 comment and name riscv: Restrict DWARF5 when building with LLVM to known working versions riscv: Hoist linker relaxation disabling logic into Kconfig Link: https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 Link: https://lore.kernel.org/r/20231205-riscv-restrict-dwarf5-llvm-v2-0-aedf00a382ac@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
-rw-r--r--arch/riscv/Kconfig14
-rw-r--r--arch/riscv/Makefile4
-rw-r--r--lib/Kconfig.debug12
3 files changed, 22 insertions, 8 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index b834d2daf95e..1070728c8321 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -183,6 +183,20 @@ config HAVE_SHADOW_CALL_STACK
# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
depends on $(ld-option,--no-relax-gp)
+config RISCV_USE_LINKER_RELAXATION
+ def_bool y
+ # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
+ depends on !LD_IS_LLD || LLD_VERSION >= 150000
+
+# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
+config ARCH_HAS_BROKEN_DWARF5
+ def_bool y
+ depends on RISCV_USE_LINKER_RELAXATION
+ # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
+ depends on AS_IS_LLVM && AS_VERSION < 180000
+ # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
+ depends on LD_IS_LLD && LLD_VERSION < 180000
+
config ARCH_MMAP_RND_BITS_MIN
default 18 if 64BIT
default 8
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index ebbe02628a27..6539e43f8276 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -43,8 +43,7 @@ else
KBUILD_LDFLAGS += -melf32lriscv
endif
-ifeq ($(CONFIG_LD_IS_LLD),y)
-ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 150000),y)
+ifndef CONFIG_RISCV_USE_LINKER_RELAXATION
KBUILD_CFLAGS += -mno-relax
KBUILD_AFLAGS += -mno-relax
ifndef CONFIG_AS_IS_LLVM
@@ -52,7 +51,6 @@ ifndef CONFIG_AS_IS_LLVM
KBUILD_AFLAGS += -Wa,-mno-relax
endif
endif
-endif
ifeq ($(CONFIG_SHADOW_CALL_STACK),y)
KBUILD_LDFLAGS += --no-relax-gp
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index cc7d53d9dc01..76c2cc697573 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -231,9 +231,10 @@ config DEBUG_INFO
in the "Debug information" choice below, indicating that debug
information will be generated for build targets.
-# Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which
-# some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
-config AS_HAS_NON_CONST_LEB128
+# Clang generates .uleb128 with label differences for DWARF v5, a feature that
+# older binutils ports do not support when utilizing RISC-V style linker
+# relaxation: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
+config AS_HAS_NON_CONST_ULEB128
def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
choice
@@ -258,7 +259,7 @@ config DEBUG_INFO_NONE
config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
bool "Rely on the toolchain's implicit default DWARF version"
select DEBUG_INFO
- depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
+ depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
help
The implicit default version of DWARF debug info produced by a
toolchain changes over time.
@@ -282,7 +283,8 @@ config DEBUG_INFO_DWARF4
config DEBUG_INFO_DWARF5
bool "Generate DWARF Version 5 debuginfo"
select DEBUG_INFO
- depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
+ depends on !ARCH_HAS_BROKEN_DWARF5
+ depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
help
Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
5.0+ accepts the -gdwarf-5 flag but only had partial support for some