arm64: rename COMPAT to AARCH32_EL0

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

Reference: https://github.com/norov/linux/commits/ilp32-5.2

--------------------------------

In this patchset ILP32 ABI support is added. Additionally to AARCH32,
which is binary-compatible with ARM, ILP32 is (mostly) ABI-compatible.

From now, AARCH32_EL0 (former COMPAT) config option means the support of
AARCH32 userspace, and ARM64_ILP32 - support of ILP32 ABI (see following
patches). COMPAT indicates that one of them or both is enabled.

Where needed, CONFIG_COMPAT is changed over to use CONFIG_AARCH32_EL0
instead.
Reviewed-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NAndrew Pinski <Andrew.Pinski@caviumnetworks.com>
Signed-off-by: NYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: NPhilipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: NChristoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: NBamvor Jian Zhang <bamv2005@gmail.com>
Signed-off-by: NYury Norov <ynorov@marvell.com>

 Conflicts:
	arch/arm64/Kconfig
	arch/arm64/include/asm/fpsimd.h
	arch/arm64/include/asm/processor.h
	arch/arm64/include/asm/signal32.h
	arch/arm64/kernel/Makefile
	arch/arm64/kernel/cpuinfo.c
	arch/arm64/kernel/cpufeature.c
	arch/arm64/kernel/entry.S
	arch/arm64/kernel/entry-common.c
	arch/arm64/kernel/syscall.c
	drivers/clocksource/arm_arch_timer.c
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>

arch/arm64/Kconfig

@@ -483,7 +483,7 @@ config ARM64_ERRATUM_834220
 
 config ARM64_ERRATUM_845719
 	bool "Cortex-A53: 845719: a load might read incorrect data"
-	depends on COMPAT
+	depends on AARCH32_EL0
 	default y
 	help
 	  This option adds an alternative code sequence to work around ARM
@@ -1214,7 +1214,7 @@ config ARM64_TAGGED_ADDR_ABI
 	  to system calls as pointer arguments. For details, see
 	  Documentation/arm64/tagged-address-abi.rst.
 
-menuconfig COMPAT
+menuconfig AARCH32_EL0
 	bool "Kernel support for 32-bit EL0"
 	depends on ARM64_4K_PAGES || EXPERT
 	select COMPAT_BINFMT_ELF if BINFMT_ELF
@@ -1233,7 +1233,7 @@ menuconfig COMPAT
 
 	  If you want to execute 32-bit userspace applications, say Y.
 
-if COMPAT
+if AARCH32_EL0
 
 config KUSER_HELPERS
 	bool "Enable kuser helpers page for 32-bit applications"
@@ -1285,6 +1285,7 @@ config THUMB2_COMPAT_VDSO
 
 menuconfig ARMV8_DEPRECATED
 	bool "Emulate deprecated/obsolete ARMv8 instructions"
+	depends on AARCH32_EL0
 	depends on SYSCTL
 	help
 	  Legacy software support may require certain instructions
@@ -1891,6 +1892,10 @@ config DMI
 
 endmenu
 
+config COMPAT
+	def_bool y
+	depends on AARCH32_EL0
+
 config SYSVIPC_COMPAT
 	def_bool y
 	depends on COMPAT && SYSVIPC

arch/arm64/include/asm/arch_timer.h

@@ -234,7 +234,7 @@ static inline int arch_timer_arch_init(void)
 static inline void arch_timer_set_evtstrm_feature(void)
 {
 	cpu_set_named_feature(EVTSTRM);
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	compat_elf_hwcap |= COMPAT_HWCAP_EVTSTRM;
 #endif
 }

arch/arm64/include/asm/fpsimd.h

@@ -21,7 +21,7 @@
 #include <linux/stddef.h>
 #include <linux/types.h>
 
-#ifdef CONFIG_COMPAT
+#ifdef 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

arch/arm64/include/asm/hwcap.h

@@ -113,7 +113,7 @@
 #define ELF_HWCAP		cpu_get_elf_hwcap()
 #define ELF_HWCAP2		cpu_get_elf_hwcap2()
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 #define COMPAT_ELF_HWCAP	(compat_elf_hwcap)
 #define COMPAT_ELF_HWCAP2	(compat_elf_hwcap2)
 extern unsigned int compat_elf_hwcap, compat_elf_hwcap2;
@@ -121,7 +121,7 @@ extern unsigned int compat_elf_hwcap, compat_elf_hwcap2;
 
 enum {
 	CAP_HWCAP = 1,
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	CAP_COMPAT_HWCAP,
 	CAP_COMPAT_HWCAP2,
 #endif

arch/arm64/include/asm/processor.h

@@ -171,7 +171,7 @@ static inline void arch_thread_struct_whitelist(unsigned long *offset,
 	*size = sizeof_field(struct thread_struct, uw);
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 #define task_user_tls(t)						\
 ({									\
 	unsigned long *__tls;						\
@@ -211,7 +211,7 @@ static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 	regs->sp = sp;
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 				       unsigned long sp)
 {

arch/arm64/include/asm/ptrace.h

@@ -213,7 +213,7 @@ static inline void forget_syscall(struct pt_regs *regs)
 
 #define arch_has_single_step()	(1)
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 #define compat_thumb_mode(regs) \
 	(((regs)->pstate & PSR_AA32_T_BIT))
 #else

arch/arm64/include/asm/seccomp.h

@@ -10,7 +10,7 @@
 
 #include <asm/unistd.h>
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 #define __NR_seccomp_read_32		__NR_compat_read
 #define __NR_seccomp_write_32		__NR_compat_write
 #define __NR_seccomp_exit_32		__NR_compat_exit

arch/arm64/include/asm/signal32.h

@@ -5,7 +5,7 @@
 #ifndef __ASM_SIGNAL32_H
 #define __ASM_SIGNAL32_H
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 #include <linux/compat.h>
 
 struct compat_sigcontext {
@@ -77,5 +77,5 @@ 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_COMPAT */
+#endif /* CONFIG_AARCH32_EL0 */
 #endif /* __ASM_SIGNAL32_H */

arch/arm64/include/asm/syscall.h

@@ -13,7 +13,7 @@ typedef long (*syscall_fn_t)(const struct pt_regs *regs);
 
 extern const syscall_fn_t sys_call_table[];
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 extern const syscall_fn_t compat_sys_call_table[];
 #endif
 

arch/arm64/include/asm/unistd.h

@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2012 ARM Ltd.
  */
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 #define __ARCH_WANT_COMPAT_STAT64
 #define __ARCH_WANT_SYS_GETHOSTNAME
 #define __ARCH_WANT_SYS_PAUSE

arch/arm64/kernel/Makefile

@@ -25,9 +25,9 @@ OBJCOPYFLAGS := --prefix-symbols=__efistub_
 $(obj)/%.stub.o: $(obj)/%.o FORCE
 	$(call if_changed,objcopy)
 
-obj-$(CONFIG_COMPAT)			+= sys32.o signal32.o			\
+obj-$(CONFIG_AARCH32_EL0)			+= sys32.o signal32.o			\
 					   sys_compat.o
-obj-$(CONFIG_COMPAT)			+= sigreturn32.o
+obj-$(CONFIG_AARCH32_EL0)			+= sigreturn32.o
 obj-$(CONFIG_KUSER_HELPERS)		+= kuser32.o
 obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace.o entry-ftrace.o
 obj-$(CONFIG_MODULES)			+= module.o

arch/arm64/kernel/asm-offsets.c

@@ -75,7 +75,7 @@ int main(void)
   DEFINE(S_STACKFRAME,		offsetof(struct pt_regs, stackframe));
   DEFINE(S_FRAME_SIZE,		sizeof(struct pt_regs));
   BLANK();
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
   DEFINE(COMPAT_SIGFRAME_REGS_OFFSET,		offsetof(struct compat_sigframe, uc.uc_mcontext.arm_r0));
   DEFINE(COMPAT_RT_SIGFRAME_REGS_OFFSET,	offsetof(struct compat_rt_sigframe, sig.uc.uc_mcontext.arm_r0));
   BLANK();

arch/arm64/kernel/cpufeature.c

@@ -84,7 +84,7 @@
 /* Kernel representation of AT_HWCAP and AT_HWCAP2 */
 static unsigned long elf_hwcap __read_mostly;
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 #define COMPAT_ELF_HWCAP_DEFAULT	\
 				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
 				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
@@ -2260,7 +2260,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 	{},
 };
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
 {
 	/*
@@ -2283,7 +2283,7 @@ static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
 #endif
 
 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON),
 	HWCAP_CAP(SYS_MVFR1_EL1, MVFR1_SIMDFMAC_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4),
 	/* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */
@@ -2304,7 +2304,7 @@ static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
 	case CAP_HWCAP:
 		cpu_set_feature(cap->hwcap);
 		break;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	case CAP_COMPAT_HWCAP:
 		compat_elf_hwcap |= (u32)cap->hwcap;
 		break;
@@ -2327,7 +2327,7 @@ static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
 	case CAP_HWCAP:
 		rc = cpu_have_feature(cap->hwcap);
 		break;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	case CAP_COMPAT_HWCAP:
 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
 		break;

arch/arm64/kernel/cpuinfo.c

@@ -96,7 +96,7 @@ static const char *const hwcap_str[] = {
 	[KERNEL_HWCAP_MTE]		= "mte",
 };
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 #define COMPAT_KERNEL_HWCAP(x)	const_ilog2(COMPAT_HWCAP_ ## x)
 static const char *const compat_hwcap_str[] = {
 	[COMPAT_KERNEL_HWCAP(SWP)]	= "swp",
@@ -131,7 +131,7 @@ static const char *const compat_hwcap2_str[] = {
 	[COMPAT_KERNEL_HWCAP2(SHA2)]	= "sha2",
 	[COMPAT_KERNEL_HWCAP2(CRC32)]	= "crc32",
 };
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_AARCH32_EL0 */
 
 static int c_show(struct seq_file *m, void *v)
 {
@@ -164,7 +164,7 @@ static int c_show(struct seq_file *m, void *v)
 		 */
 		seq_puts(m, "Features\t:");
 		if (compat) {
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 			for (j = 0; j < ARRAY_SIZE(compat_hwcap_str); j++) {
 				if (compat_elf_hwcap & (1 << j)) {
 					/*
@@ -181,7 +181,7 @@ static int c_show(struct seq_file *m, void *v)
 			for (j = 0; j < ARRAY_SIZE(compat_hwcap2_str); j++)
 				if (compat_elf_hwcap2 & (1 << j))
 					seq_printf(m, " %s", compat_hwcap2_str[j]);
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_AARCH32_EL0 */
 		} else {
 			for (j = 0; j < ARRAY_SIZE(hwcap_str); j++)
 				if (cpu_have_feature(j))

arch/arm64/kernel/entry-common.c

@@ -427,7 +427,7 @@ asmlinkage void noinstr el0_sync_handler(struct pt_regs *regs)
 	}
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 static void noinstr el0_cp15(struct pt_regs *regs, unsigned long esr)
 {
 	enter_from_user_mode();
@@ -487,4 +487,4 @@ asmlinkage void noinstr el0_sync_compat_handler(struct pt_regs *regs)
 		el0_inv(regs, esr);
 	}
 }
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_AARCH32_EL0 */

arch/arm64/kernel/entry.S

@@ -526,7 +526,7 @@ SYM_CODE_START(vectors)
 	kernel_ventry	0, fiq_invalid			// FIQ 64-bit EL0
 	kernel_ventry	0, error			// Error 64-bit EL0
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	kernel_ventry	0, sync_compat, 32		// Synchronous 32-bit EL0
 	kernel_ventry	0, irq_compat, 32		// IRQ 32-bit EL0
 	kernel_ventry	0, fiq_invalid_compat, 32	// FIQ 32-bit EL0
@@ -595,7 +595,7 @@ SYM_CODE_START_LOCAL(el0_error_invalid)
 	inv_entry 0, BAD_ERROR
 SYM_CODE_END(el0_error_invalid)
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 SYM_CODE_START_LOCAL(el0_fiq_invalid_compat)
 	inv_entry 0, BAD_FIQ, 32
 SYM_CODE_END(el0_fiq_invalid_compat)
@@ -671,7 +671,7 @@ SYM_CODE_START_LOCAL_NOALIGN(el0_sync)
 	b	ret_to_user
 SYM_CODE_END(el0_sync)
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	.align	6
 SYM_CODE_START_LOCAL_NOALIGN(el0_sync_compat)
 	kernel_entry 0, 32

arch/arm64/kernel/head.S

@@ -563,7 +563,7 @@ set_hcr:
 	msr	vpidr_el2, x0
 	msr	vmpidr_el2, x1
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	msr	hstr_el2, xzr			// Disable CP15 traps to EL2
 #endif
 

arch/arm64/kernel/perf_callchain.c

@@ -52,7 +52,7 @@ user_backtrace(struct frame_tail __user *tail,
 	return buftail.fp;
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 /*
  * The registers we're interested in are at the end of the variable
  * length saved register structure. The fp points at the end of this
@@ -97,7 +97,7 @@ compat_user_backtrace(struct compat_frame_tail __user *tail,
 
 	return (struct compat_frame_tail __user *)compat_ptr(buftail.fp) - 1;
 }
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_AARCH32_EL0 */
 
 void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
 			 struct pt_regs *regs)
@@ -119,7 +119,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
 		       tail && !((unsigned long)tail & 0xf))
 			tail = user_backtrace(tail, entry);
 	} else {
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 		/* AARCH32 compat mode */
 		struct compat_frame_tail __user *tail;
 

arch/arm64/kernel/ptrace.c

@@ -174,7 +174,7 @@ static void ptrace_hbptriggered(struct perf_event *bp,
 	struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 	const char *desc = "Hardware breakpoint trap (ptrace)";
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	if (is_compat_task()) {
 		int si_errno = 0;
 		int i;
@@ -1198,7 +1198,9 @@ 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 {
 	REGSET_COMPAT_GPR,
 	REGSET_COMPAT_VFP,
@@ -1712,11 +1714,11 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 
 	return ret;
 }
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_AARCH32_EL0 */
 
 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

arch/arm64/kernel/syscall.c

@@ -19,7 +19,7 @@ long sys_ni_syscall(void);
 
 static long do_ni_syscall(struct pt_regs *regs, int scno)
 {
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 	long ret;
 	if (is_compat_task()) {
 		ret = compat_arm_syscall(regs, scno);
@@ -204,7 +204,7 @@ void do_el0_svc(struct pt_regs *regs)
 	el0_svc_common(regs, regs->regs[8], __NR_syscalls, sys_call_table);
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 void do_el0_svc_compat(struct pt_regs *regs)
 {
 	el0_svc_common(regs, regs->regs[7], __NR_compat_syscalls,

arch/arm64/kernel/vdso.c

@@ -276,7 +276,7 @@ static int __setup_additional_pages(enum vdso_abi abi,
 	return PTR_ERR(ret);
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_AARCH32_EL0
 /*
  * Create and map the vectors page for AArch32 tasks.
  */
@@ -451,7 +451,7 @@ int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 	mmap_write_unlock(mm);
 	return ret;
 }
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_AARCH32_EL0 */
 
 static int vdso_mremap(const struct vm_special_mapping *sm,
 		struct vm_area_struct *new_vma)