RISC-V: vdso: Do not add missing symbols to version section in linker script

Recently, ld.lld moved from '--undefined-version' to
'--no-undefined-version' as the default, which breaks the compat vDSO
build:

  ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_gettimeofday' failed: symbol not defined
  ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_clock_gettime' failed: symbol not defined
  ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_clock_getres' failed: symbol not defined

These symbols are not present in the compat vDSO or the regular vDSO for
32-bit but they are unconditionally included in the version section of
the linker script, which is prohibited with '--no-undefined-version'.

Fix this issue by only including the symbols that are actually exported
in the version section of the linker script.

Link: https://github.com/ClangBuiltLinux/linux/issues/1756
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221108171324.3377226-1-nathan@kernel.org/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Nathan Chancellor 2022-11-08 10:13:23 -07:00 committed by Palmer Dabbelt
parent 50e63dd8ed
commit fcae44fd36
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2 changed files with 5 additions and 0 deletions

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@ -28,6 +28,9 @@ obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
obj-y += vdso.o
CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
ifneq ($(filter vgettimeofday, $(vdso-syms)),)
CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY
endif
# Disable -pg to prevent insert call site
CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE)

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@ -68,9 +68,11 @@ VERSION
LINUX_4.15 {
global:
__vdso_rt_sigreturn;
#ifdef HAS_VGETTIMEOFDAY
__vdso_gettimeofday;
__vdso_clock_gettime;
__vdso_clock_getres;
#endif
__vdso_getcpu;
__vdso_flush_icache;
local: *;