From: Paul Burton <paul.burton@xxxxxxxx> commit 351fdddd366245c0fb4636f32edfb4198c8d6b8c upstream. VDSO code should not be using smp_processor_id(), since it is executed in user mode. Introduce a VDSO-specific path which will cause a compile-time or link-time error (depending upon support for __compiletime_error) if the VDSO ever incorrectly attempts to use smp_processor_id(). [Matt Redfearn <matt.redfearn@xxxxxxxxxx>: Move before change to smp_processor_id in series] Signed-off-by: Paul Burton <paul.burton@xxxxxxxx> Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxx> Patchwork: https://patchwork.linux-mips.org/patch/17932/ Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: James Hogan <jhogan@xxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/include/asm/smp.h | 12 +++++++++++- arch/mips/vdso/Makefile | 3 ++- 2 files changed, 13 insertions(+), 2 deletions(-) --- a/arch/mips/include/asm/smp.h +++ b/arch/mips/include/asm/smp.h @@ -25,7 +25,17 @@ extern cpumask_t cpu_sibling_map[]; extern cpumask_t cpu_core_map[]; extern cpumask_t cpu_foreign_map[]; -#define raw_smp_processor_id() (current_thread_info()->cpu) +static inline int raw_smp_processor_id(void) +{ +#if defined(__VDSO__) + extern int vdso_smp_processor_id(void) + __compiletime_error("VDSO should not call smp_processor_id()"); + return vdso_smp_processor_id(); +#else + return current_thread_info()->cpu; +#endif +} +#define raw_smp_processor_id raw_smp_processor_id /* Map from cpu id to sequential logical cpu number. This will only not be idempotent when cpus failed to come on-line. */ --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -7,7 +7,8 @@ ccflags-vdso := \ $(filter -I%,$(KBUILD_CFLAGS)) \ $(filter -E%,$(KBUILD_CFLAGS)) \ $(filter -mmicromips,$(KBUILD_CFLAGS)) \ - $(filter -march=%,$(KBUILD_CFLAGS)) + $(filter -march=%,$(KBUILD_CFLAGS)) \ + -D__VDSO__ cflags-vdso := $(ccflags-vdso) \ $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ -O2 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ Patches currently in stable-queue which might be from paul.burton@xxxxxxxx are queue-4.14/revert-mips-sibyte-enable-swiotlb-for-swarm-littlesur-and.patch queue-4.14/mips-vdso-use-same-m-float-cflag-as-the-kernel-proper.patch queue-4.14/mips-vdso-prevent-use-of-smp_processor_id.patch
