Subject: [PATCH v5 04/23] arm64: change some CONFIG_COMPAT over to use CONFIG_AARCH32_EL0 instead

From: [email-masked] (Andrey Konovalov)
Date: Tue, 6 Oct 2015 12:21:20 +0300

Hi Yury,

With this patch set 4.3 kernel fails to build with both arch/arm64/configs/defconfig,
and with arch/arm64/configs/defconfig plus CONFIG_AARCH32_EL0=y and CONFIG_ARM64_ILP32=y.
See the details below.

Thanks,
Andrey

On 09/30/2015 01:14 AM, Yury Norov wrote:
> From: Andrew Pinski <[email-masked]>
>
> Signed-off-by: Philipp Tomsich <[email-masked]>
> Signed-off-by: Christoph Muellner <[email-masked]>
> Signed-off-by: Yury Norov <[email-masked]>
>
> diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
> index faad6df..f40c51b 100644
> --- a/arch/arm64/include/asm/elf.h
> +++ b/arch/arm64/include/asm/elf.h
> @@ -166,10 +166,13 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,
>
>   #define COMPAT_ELF_ET_DYN_BASE		(2 * TASK_SIZE_32 / 3)
>
> +
> +#ifdef CONFIG_AARCH32_EL0
> +
>   /* AArch32 registers. */
> -#define COMPAT_ELF_NGREG		18
> +#define COMPAT_A32_ELF_NGREG		18
>   typedef unsigned int			compat_elf_greg_t;
> -typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];
> +typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_A32_ELF_NGREG];
>
>   /* AArch32 EABI. */
>   #define EF_ARM_EABI_MASK		0xff000000
> @@ -179,11 +182,25 @@ typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];
>   #define compat_start_thread		compat_start_thread
>   #define COMPAT_SET_PERSONALITY(ex)	set_thread_flag(TIF_32BIT);
>   #define COMPAT_ARCH_DLINFO
> +
> +
>   extern int aarch32_setup_vectors_page(struct linux_binprm *bprm,
>   				      int uses_interp);
>   #define compat_arch_setup_additional_pages \
>   					aarch32_setup_vectors_page
>
> +#else
> +
> +typedef elf_greg_t			compat_elf_greg_t;
> +typedef elf_gregset_t			compat_elf_gregset_t;
> +#define compat_a32_elf_check_arch(x)	0
> +#define COMPAT_SET_PERSONALITY(ex)
> +#define COMPAT_ARCH_DLINFO
> +
> +#endif
> +
> +#define compat_elf_check_arch(x)	compat_a32_elf_check_arch(x)
> +
>   #endif /* CONFIG_COMPAT */
>
>   #endif
> diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
> index 50f559f..63b19f1 100644
> --- a/arch/arm64/include/asm/fpsimd.h
> +++ b/arch/arm64/include/asm/fpsimd.h
> @@ -52,7 +52,7 @@ struct fpsimd_partial_state {
>   };
>
>
> -#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
> +#if defined(__KERNEL__) && defined(CONFIG_AARCH32_EL0)
>   /* Masks for extracting the FPSR and FPCR from the FPSCR */
>   #define VFP_FPSCR_STAT_MASK	0xf800009f
>   #define VFP_FPSCR_CTRL_MASK	0x07f79f00
> diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
> index 536274e..1059b3f 100644
> --- a/arch/arm64/include/asm/ptrace.h
> +++ b/arch/arm64/include/asm/ptrace.h
> @@ -120,7 +120,7 @@ struct pt_regs {
>
>   #define arch_has_single_step()	(1)
>
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   #define compat_thumb_mode(regs) \
>   	(((regs)->pstate & COMPAT_PSR_T_BIT))
>   #else
> diff --git a/arch/arm64/include/asm/signal32.h b/arch/arm64/include/asm/signal32.h
> index eeaa975..4302909 100644
> --- a/arch/arm64/include/asm/signal32.h
> +++ b/arch/arm64/include/asm/signal32.h
> @@ -20,6 +20,7 @@
>   #ifdef CONFIG_COMPAT
>   #include <linux/compat.h>
>
> +#ifdef CONFIG_AARCH32_EL0
>   #define AARCH32_KERN_SIGRET_CODE_OFFSET	0x500
>
>   extern const compat_ulong_t aarch32_sigret_code[6];
> @@ -47,6 +48,7 @@ static inline int compat_setup_rt_frame(int usig, struct ksignal *ksig, sigset_t
>   static inline void compat_setup_restart_syscall(struct pt_regs *regs)
>   {
>   }
> +#endif /* CONFIG_AARCH32_EL0 */
>   #endif /* CONFIG_COMPAT */
>   #endif /* __KERNEL__ */
>   #endif /* __ASM_SIGNAL32_H */
> diff --git a/arch/arm64/include/asm/stat.h b/arch/arm64/include/asm/stat.h
> index 15e3559..af04276 100644
> --- a/arch/arm64/include/asm/stat.h
> +++ b/arch/arm64/include/asm/stat.h
> @@ -22,6 +22,7 @@
>
>   #include <asm/compat.h>
>
> +#ifdef CONFIG_AARCH32_EL0
>   /*
>    * struct stat64 is needed for compat tasks only. Its definition is different
>    * from the generic struct stat64.
> @@ -59,3 +60,4 @@ struct stat64 {
>
>   #endif
>   #endif
> +#endif
> diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
> index 3bc498c..759c433 100644
> --- a/arch/arm64/include/asm/unistd.h
> +++ b/arch/arm64/include/asm/unistd.h
> @@ -13,7 +13,7 @@
>    * You should have received a copy of the GNU General Public License
>    * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>    */
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   #define __ARCH_WANT_COMPAT_SYS_GETDENTS64
>   #define __ARCH_WANT_COMPAT_STAT64
>   #define __ARCH_WANT_SYS_GETHOSTNAME
> @@ -26,7 +26,9 @@
>   #define __ARCH_WANT_COMPAT_SYS_SENDFILE
>   #define __ARCH_WANT_SYS_FORK
>   #define __ARCH_WANT_SYS_VFORK
> +#endif
>
> +#ifdef CONFIG_COMPAT
>   /*
>    * Compat syscall numbers used by the AArch64 kernel.
>    */
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index 22dc9bc..1470332 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -20,7 +20,7 @@ arm64-obj-y		:= debug-monitors.o entry.o irq.o fpsimd.o		\
>   			   cpufeature.o alternative.o cacheinfo.o		\
>   			   smp.o smp_spin_table.o topology.o
>
> -arm64-obj-$(CONFIG_COMPAT)		+= sys32.o kuser32.o signal32.o 	\
> +arm64-obj-$(CONFIG_AARCH32_EL0)		+= sys32.o kuser32.o signal32.o 	\
>   					   sys_compat.o entry32.o		\
>   					   ../../arm/kernel/opcodes.o
>   arm64-obj-$(CONFIG_FUNCTION_TRACER)	+= ftrace.o entry-ftrace.o
> diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
> index 8d89cf8..e3bcf77 100644
> --- a/arch/arm64/kernel/asm-offsets.c
> +++ b/arch/arm64/kernel/asm-offsets.c
> @@ -51,7 +51,7 @@ int main(void)
>     DEFINE(S_X7,			offsetof(struct pt_regs, regs[7]));
>     DEFINE(S_LR,			offsetof(struct pt_regs, regs[30]));
>     DEFINE(S_SP,			offsetof(struct pt_regs, sp));
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>     DEFINE(S_COMPAT_SP,		offsetof(struct pt_regs, compat_sp));
>   #endif
>     DEFINE(S_PSTATE,		offsetof(struct pt_regs, pstate));
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index 4306c93..52be5c8 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -212,7 +212,7 @@ ENTRY(vectors)
>   	ventry	el0_fiq_invalid			// FIQ 64-bit EL0
>   	ventry	el0_error_invalid		// Error 64-bit EL0
>
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   	ventry	el0_sync_compat			// Synchronous 32-bit EL0
>   	ventry	el0_irq_compat			// IRQ 32-bit EL0
>   	ventry	el0_fiq_invalid_compat		// FIQ 32-bit EL0
> @@ -252,7 +252,7 @@ el0_error_invalid:
>   	inv_entry 0, BAD_ERROR
>   ENDPROC(el0_error_invalid)
>
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   el0_fiq_invalid_compat:
>   	inv_entry 0, BAD_FIQ, 32
>   ENDPROC(el0_fiq_invalid_compat)
> @@ -414,7 +414,7 @@ el0_sync:
>   	b.ge	el0_dbg
>   	b	el0_inv
>
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   	.align	6
>   el0_sync_compat:
>   	kernel_entry 0, 32
> diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
> index 90d09ed..d11d0b2 100644
> --- a/arch/arm64/kernel/head.S
> +++ b/arch/arm64/kernel/head.S
> @@ -519,7 +519,7 @@ CPU_LE(	movk	x0, #0x30d0, lsl #16	)	// Clear EE and E0E on LE systems
>   	mov	x0, #0x33ff
>   	msr	cptr_el2, x0			// Disable copro. traps to EL2
>
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   	msr	hstr_el2, xzr			// Disable CP15 traps to EL2
>   #endif
>
> diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
> index 1971f49..04b4972 100644
> --- a/arch/arm64/kernel/ptrace.c
> +++ b/arch/arm64/kernel/ptrace.c
> @@ -76,7 +76,7 @@ static void ptrace_hbptriggered(struct perf_event *bp,
>   		.si_addr	= (void __user *)(bkpt->trigger),
>   	};
>
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   	int i;
>
>   	if (!is_compat_task())
> @@ -651,7 +651,7 @@ static const struct user_regset_view user_aarch64_view = {
>   	.regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
>   };
>
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   #include <linux/compat.h>
>
>   enum compat_regset {
> @@ -853,7 +853,7 @@ static int compat_tls_set(struct task_struct *target,
>   static const struct user_regset aarch32_regsets[] = {
>   	[REGSET_COMPAT_GPR] = {
>   		.core_note_type = NT_PRSTATUS,
> -		.n = COMPAT_ELF_NGREG,
> +		.n = COMPAT_A32_ELF_NGREG,

Commit 5d220ff9 "arm64: Better native ptrace support for compat tasks" added
struct user_regset aarch32_ptrace_regsets[]
and hence one more COMPAT_ELF_NGREG, which is not handled by this patch.
This resulted in the following build failure in my ILP32 configuration (arch/arm64/configs/defconfig
plus CONFIG_AARCH32_EL0=y and CONFIG_ARM64_ILP32=y):
-----8<-----
  ../arch/arm64/kernel/ptrace.c:880:8: error: 'COMPAT_ELF_NGREG' undeclared here (not in a function)
     .n = COMPAT_ELF_NGREG,
          ^
-----8<-----

>   		.size = sizeof(compat_elf_greg_t),
>   		.align = sizeof(compat_elf_greg_t),
>   		.get = compat_gpr_get,
> @@ -1109,8 +1109,8 @@ static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
>   }
>   #endif	/* CONFIG_HAVE_HW_BREAKPOINT */
>
> -long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
> -			compat_ulong_t caddr, compat_ulong_t cdata)
> +long compat_a32_arch_ptrace(struct task_struct *child, compat_long_t request,
> +			    compat_ulong_t caddr, compat_ulong_t cdata)
>   {
>   	unsigned long addr = caddr;
>   	unsigned long data = cdata;
> @@ -1186,11 +1186,28 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
>
>   	return ret;
>   }
> -#endif /* CONFIG_COMPAT */
> +#else /* !CONFIG_AARCH32_EL0 */
> +long compat_a32_arch_ptrace(struct task_struct *child, compat_long_t request,
> +			    compat_ulong_t caddr, compat_ulong_t cdata)
> +{
> +	return -1;
> +}
> +#endif /* !CONFIG_AARCH32_EL0 */

Building with arm64's defconfig (CONFIG_AARCH32_EL0, CONFIG_COMPAT, and CONFIG_ARM64_ILP32 aren't set)
fails this way - due to compat_[u]long_t not being defined in !CONFIG_COMPAT case:

-----8<-----
../arch/arm64/kernel/ptrace.c:1190:56: error: unknown type name 'compat_long_t'
  long compat_a32_arch_ptrace(struct task_struct *child, compat_long_t request,
                                                         ^
../arch/arm64/kernel/ptrace.c:1191:8: error: unknown type name 'compat_ulong_t'
         compat_ulong_t caddr, compat_ulong_t cdata)
         ^
../arch/arm64/kernel/ptrace.c:1191:30: error: unknown type name 'compat_ulong_t'
         compat_ulong_t caddr, compat_ulong_t cdata)
                               ^
-----8<-----

> +#ifdef CONFIG_COMPAT
> +long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
> +			compat_ulong_t caddr, compat_ulong_t cdata)
> +{
> +	if (is_compat_task())
> +		return compat_a32_arch_ptrace(child, request, caddr, cdata);
> +	return compat_ptrace_request(child, request, caddr, cdata);
> +}
> +#endif
> +
>
>   const struct user_regset_view *task_user_regset_view(struct task_struct *task)
>   {
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   	/*
>   	 * Core dumping of 32-bit tasks or compat ptrace requests must use the
>   	 * user_aarch32_view compatible with arm32. Native ptrace requests on
> diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
> index e18c48c..964a2a4 100644
> --- a/arch/arm64/kernel/signal.c
> +++ b/arch/arm64/kernel/signal.c
> @@ -414,3 +414,18 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
>   		fpsimd_restore_current_state();
>
>   }
> +
> +/*
> + * Some functions are needed for compat ptrace but we don't define
> + * them if we don't have AARCH32 support compiled in
> + */
> +#if defined CONFIG_COMPAT && !defined CONFIG_AARCH32_EL0
> +int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
> +{
> +	return -EFAULT;
> +}
> +int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
> +{
> +	return -EFAULT;
> +}
> +#endif
> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
> index f93aae5..9ce9894 100644
> --- a/arch/arm64/kernel/traps.c
> +++ b/arch/arm64/kernel/traps.c
> @@ -363,7 +363,7 @@ long compat_arm_syscall(struct pt_regs *regs);
>
>   asmlinkage long do_ni_syscall(struct pt_regs *regs)
>   {
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   	long ret;
>   	if (is_compat_task()) {
>   		ret = compat_arm_syscall(regs);
> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index 97bc68f..26352a6 100644
> --- a/arch/arm64/kernel/vdso.c
> +++ b/arch/arm64/kernel/vdso.c
> @@ -49,7 +49,7 @@ static union {
>   } vdso_data_store __page_aligned_data;
>   struct vdso_data *vdso_data = &vdso_data_store.data;
>
> -#ifdef CONFIG_COMPAT
> +#ifdef CONFIG_AARCH32_EL0
>   /*
>    * Create and map the vectors page for AArch32 tasks.
>    */
> @@ -107,7 +107,7 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
>
>   	return PTR_ERR_OR_ZERO(ret);
>   }
> -#endif /* CONFIG_COMPAT */
> +#endif /* CONFIG_AARCH32_EL0 */
>
>   static struct vm_special_mapping vdso_spec[2];
>
>