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| author | Paul Burton <paulburton@kernel.org> | 2020-02-15 21:38:36 +0100 |
|---|---|---|
| committer | Paul Burton <paulburton@kernel.org> | 2020-02-15 21:44:03 +0100 |
| commit | 07015d7a103c4420b69a287b8ef4d2535c0f4106 (patch) | |
| tree | 1c5ff6960b01e120f96a7dc4c8fe4da03969346a /arch/mips/vdso | |
| parent | mips: vdso: fix 'jalr t9' crash in vdso code (diff) | |
| download | linux-07015d7a103c4420b69a287b8ef4d2535c0f4106.tar.xz linux-07015d7a103c4420b69a287b8ef4d2535c0f4106.zip | |
MIPS: Disable VDSO time functionality on microMIPS
A check we're about to add to pick up on function calls that depend on
bogus use of the GOT in the VDSO picked up on instances of such function
calls in microMIPS builds. Since the code appears genuinely problematic,
and given the relatively small amount of use & testing that microMIPS
sees, go ahead & disable the VDSO for microMIPS builds.
Signed-off-by: Paul Burton <paulburton@kernel.org>
Diffstat (limited to 'arch/mips/vdso')
| -rw-r--r-- | arch/mips/vdso/Makefile | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index 848baeaef1f8..b5e0bd82d47f 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -52,6 +52,8 @@ endif CFLAGS_REMOVE_vgettimeofday.o = -pg +DISABLE_VDSO := n + # # For the pre-R6 code in arch/mips/vdso/vdso.h for locating # the base address of VDSO, the linker will emit a R_MIPS_PC32 @@ -65,11 +67,24 @@ CFLAGS_REMOVE_vgettimeofday.o = -pg ifndef CONFIG_CPU_MIPSR6 ifeq ($(call ld-ifversion, -lt, 225000000, y),y) $(warning MIPS VDSO requires binutils >= 2.25) - obj-vdso-y := $(filter-out vgettimeofday.o, $(obj-vdso-y)) - ccflags-vdso += -DDISABLE_MIPS_VDSO + DISABLE_VDSO := y endif endif +# +# GCC (at least up to version 9.2) appears to emit function calls that make use +# of the GOT when targeting microMIPS, which we can't use in the VDSO due to +# the lack of relocations. As such, we disable the VDSO for microMIPS builds. +# +ifdef CONFIG_CPU_MICROMIPS + DISABLE_VDSO := y +endif + +ifeq ($(DISABLE_VDSO),y) + obj-vdso-y := $(filter-out vgettimeofday.o, $(obj-vdso-y)) + ccflags-vdso += -DDISABLE_MIPS_VDSO +endif + # VDSO linker flags. VDSO_LDFLAGS := \ -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1 \ |