[v6,15/19] arm64: Add vDSO compat support
diff mbox series

Message ID 20190530141531.43462-16-vincenzo.frascino@arm.com
State New
Headers show
Series
  • Unify vDSOs across more architectures
Related show

Commit Message

Vincenzo Frascino May 30, 2019, 2:15 p.m. UTC
Add vDSO compat support to the arm64 building system.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/arm64/Kconfig         |  1 +
 arch/arm64/Makefile        | 23 +++++++++++++++++++++--
 arch/arm64/kernel/Makefile |  6 +++++-
 3 files changed, 27 insertions(+), 3 deletions(-)

Comments

Catalin Marinas June 1, 2019, 9:38 a.m. UTC | #1
On Thu, May 30, 2019 at 03:15:27PM +0100, Vincenzo Frascino wrote:
> Add vDSO compat support to the arm64 building system.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> ---
>  arch/arm64/Kconfig         |  1 +
>  arch/arm64/Makefile        | 23 +++++++++++++++++++++--
>  arch/arm64/kernel/Makefile |  6 +++++-
>  3 files changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 952c9f8cf3b8..3e1d4f8347f4 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -108,6 +108,7 @@ config ARM64
>  	select GENERIC_STRNLEN_USER
>  	select GENERIC_TIME_VSYSCALL
>  	select GENERIC_GETTIMEOFDAY
> +	select GENERIC_COMPAT_VDSO if !CPU_BIG_ENDIAN

This select needs to also depend on COMPAT (or rather be selected from
the COMPAT menuconfig), otherwise, trying to build this series with 64K
pages where COMPAT is disabled, I get:

  VDSOC_GTD   arch/arm64/kernel/vdso32/vgettimeofday.o
  VDSOA   arch/arm64/kernel/vdso32/sigreturn.o
arch/arm64/kernel/vdso32/sigreturn.S: Assembler messages:
arch/arm64/kernel/vdso32/sigreturn.S:25: Error: expected #constant
arch/arm64/kernel/vdso32/sigreturn.S:35: Error: expected #constant
arch/arm64/kernel/vdso32/sigreturn.S:46: Error: expected #constant
arch/arm64/kernel/vdso32/sigreturn.S:56: Error: expected #constant
arch/arm64/kernel/vdso32/sigreturn.S:28: Error: undefined symbol __NR_compat_sigreturn used as an immediate value
arch/arm64/kernel/vdso32/sigreturn.S:38: Error: undefined symbol __NR_compat_rt_sigreturn used as an immediate value
make[2]: *** [arch/arm64/kernel/vdso32/Makefile:154: arch/arm64/kernel/vdso32/sigreturn.o] Error 1
make[2]: *** Waiting for unfinished jobs....
In file included from lib/vdso/gettimeofday.c:25:0,
                 from <command-line>:0:
arch/arm64/include/asm/vdso/compat_gettimeofday.h: In function 'gettimeofday_fallback':
arch/arm64/include/asm/vdso/compat_gettimeofday.h:22:31: error: '__NR_compat_gettimeofday' undeclared (first use in this function); did you mean '__NR_gettimeofday'?
  register long nr asm("r7") = __NR_compat_gettimeofday;
                               ^~~~~~~~~~~~~~~~~~~~~~~~
                               __NR_gettimeofday
arch/arm64/include/asm/vdso/compat_gettimeofday.h:22:31: note: each undeclared identifier is reported only once for each function it appears in
arch/arm64/include/asm/vdso/compat_gettimeofday.h: In function 'clock_gettime_fallback':
arch/arm64/include/asm/vdso/compat_gettimeofday.h:40:31: error: '__NR_compat_clock_gettime64' undeclared (first use in this function); did you mean '__NR_clock_gettime'?
  register long nr asm("r7") = __NR_compat_clock_gettime64;
                               ^~~~~~~~~~~~~~~~~~~~~~~~~~~
                               __NR_clock_gettime
arch/arm64/include/asm/vdso/compat_gettimeofday.h: In function 'clock_getres_fallback':
arch/arm64/include/asm/vdso/compat_gettimeofday.h:58:31: error: '__NR_compat_clock_getres_time64' undeclared (first use in this function); did you mean '__NR_clock_gettime'?
  register long nr asm("r7") = __NR_compat_clock_getres_time64;
                               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                               __NR_clock_gettime
arch/arm64/kernel/vdso32/vgettimeofday.c: In function '__vdso_clock_gettime':
arch/arm64/kernel/vdso32/vgettimeofday.c:15:17: error: 'TASK_SIZE_32' undeclared (first use in this function); did you mean 'TASK_SIZE_64'?
  if ((u32)ts >= TASK_SIZE_32)
                 ^~~~~~~~~~~~
                 TASK_SIZE_64
arch/arm64/kernel/vdso32/vgettimeofday.c: In function '__vdso_clock_gettime64':
arch/arm64/kernel/vdso32/vgettimeofday.c:25:17: error: 'TASK_SIZE_32' undeclared (first use in this function); did you mean 'TASK_SIZE_64'?
  if ((u32)ts >= TASK_SIZE_32)
                 ^~~~~~~~~~~~
                 TASK_SIZE_64
arch/arm64/kernel/vdso32/vgettimeofday.c: In function '__vdso_clock_getres':
arch/arm64/kernel/vdso32/vgettimeofday.c:41:18: error: 'TASK_SIZE_32' undeclared (first use in this function); did you mean 'TASK_SIZE_64'?
  if ((u32)res >= TASK_SIZE_32)
                  ^~~~~~~~~~~~
                  TASK_SIZE_64
make[2]: *** [arch/arm64/kernel/vdso32/Makefile:152: arch/arm64/kernel/vdso32/vgettimeofday.o] Error 1
make[1]: *** [arch/arm64/Makefile:182: vdso_prepare] Error 2
make: *** [Makefile:179: sub-make] Error 2
Vincenzo Frascino June 4, 2019, 12:10 p.m. UTC | #2
Hi Catalin,

thank you for testing my patches and providing the scripts you used to reproduce
the issue.

On 01/06/2019 10:38, Catalin Marinas wrote:
> On Thu, May 30, 2019 at 03:15:27PM +0100, Vincenzo Frascino wrote:
>> Add vDSO compat support to the arm64 building system.
>>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will.deacon@arm.com>
>> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
>> ---
>>  arch/arm64/Kconfig         |  1 +
>>  arch/arm64/Makefile        | 23 +++++++++++++++++++++--
>>  arch/arm64/kernel/Makefile |  6 +++++-
>>  3 files changed, 27 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 952c9f8cf3b8..3e1d4f8347f4 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -108,6 +108,7 @@ config ARM64
>>  	select GENERIC_STRNLEN_USER
>>  	select GENERIC_TIME_VSYSCALL
>>  	select GENERIC_GETTIMEOFDAY
>> +	select GENERIC_COMPAT_VDSO if !CPU_BIG_ENDIAN
> 
> This select needs to also depend on COMPAT (or rather be selected from
> the COMPAT menuconfig), otherwise, trying to build this series with 64K
> pages where COMPAT is disabled, I get:
> 

This is a very good catch, my bad, will definitely fix in v7.

...

Patch
diff mbox series

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 952c9f8cf3b8..3e1d4f8347f4 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -108,6 +108,7 @@  config ARM64
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_COMPAT_VDSO if !CPU_BIG_ENDIAN
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_PCI
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index b025304bde46..4db50d4b2476 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -49,9 +49,25 @@  $(warning Detected assembler with broken .inst; disassembly will be unreliable)
   endif
 endif
 
-KBUILD_CFLAGS	+= -mgeneral-regs-only $(lseinstr) $(brokengasinst)
+ifeq ($(CONFIG_GENERIC_COMPAT_VDSO), y)
+  CROSS_COMPILE_COMPAT ?= $(CONFIG_CROSS_COMPILE_COMPAT_VDSO:"%"=%)
+
+  ifeq ($(CONFIG_CC_IS_CLANG), y)
+    $(warning CROSS_COMPILE_COMPAT is clang, the compat vDSO will not be built)
+  else ifeq ($(CROSS_COMPILE_COMPAT),)
+    $(warning CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built)
+  else ifeq ($(shell which $(CROSS_COMPILE_COMPAT)gcc 2> /dev/null),)
+    $(error $(CROSS_COMPILE_COMPAT)gcc not found, check CROSS_COMPILE_COMPAT)
+  else
+    export CROSS_COMPILE_COMPAT
+    export CONFIG_COMPAT_VDSO := y
+    compat_vdso := -DCONFIG_COMPAT_VDSO=1
+  endif
+endif
+
+KBUILD_CFLAGS	+= -mgeneral-regs-only $(lseinstr) $(brokengasinst) $(compat_vdso)
 KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables
-KBUILD_AFLAGS	+= $(lseinstr) $(brokengasinst)
+KBUILD_AFLAGS	+= $(lseinstr) $(brokengasinst) $(compat_vdso)
 
 KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
 KBUILD_AFLAGS	+= $(call cc-option,-mabi=lp64)
@@ -163,6 +179,9 @@  ifeq ($(KBUILD_EXTMOD),)
 prepare: vdso_prepare
 vdso_prepare: prepare0
 	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
+	$(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
+		$(build)=arch/arm64/kernel/vdso32  \
+		include/generated/vdso32-offsets.h)
 endif
 
 define archhelp
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 9e7dcb2c31c7..478491f07b4f 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -28,7 +28,10 @@  $(obj)/%.stub.o: $(obj)/%.o FORCE
 	$(call if_changed,objcopy)
 
 obj-$(CONFIG_COMPAT)			+= sys32.o signal32.o			\
-					   sigreturn32.o sys_compat.o
+					   sys_compat.o
+ifneq ($(CONFIG_COMPAT_VDSO), y)
+obj-$(CONFIG_COMPAT)			+= sigreturn32.o
+endif
 obj-$(CONFIG_KUSER_HELPERS)		+= kuser32.o
 obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace.o entry-ftrace.o
 obj-$(CONFIG_MODULES)			+= module.o
@@ -62,6 +65,7 @@  obj-$(CONFIG_ARM64_SSBD)		+= ssbd.o
 obj-$(CONFIG_ARM64_PTR_AUTH)		+= pointer_auth.o
 
 obj-y					+= vdso/ probes/
+obj-$(CONFIG_COMPAT_VDSO)		+= vdso32/
 head-y					:= head.o
 extra-y					+= $(head-y) vmlinux.lds