Merge git://git.kernel.org:/pub/scm/linux/kernel/git/davem/sparc

Pull sparc updates from David Miller:
 "Just some more random bits from Al, including a conversion over to
  generic extables"

* git://git.kernel.org:/pub/scm/linux/kernel/git/davem/sparc:
  sparc32: take ->thread.flags out
  sparc32: get rid of fake_swapper_regs
  sparc64: get rid of fake_swapper_regs
  sparc32: switch to generic extables
  sparc32: switch copy_user.S away from range exception table entries
  sparc32: get rid of range exception table entries in checksum_32.S
  sparc32: switch __bzero() away from range exception table entries
  sparc32: kill lookup_fault()
  sparc32: don't bother with lookup_fault() in __bzero()

arch/sparc/include/asm/elf_64.h

@@ -8,7 +8,6 @@
 
 #include <asm/ptrace.h>
 #include <asm/processor.h>
-#include <asm/extable_64.h>
 #include <asm/spitfire.h>
 #include <asm/adi.h>
 

arch/sparc/include/asm/extable_64.h → arch/sparc/include/asm/extable.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ASM_EXTABLE64_H
-#define __ASM_EXTABLE64_H
+#ifndef __ASM_EXTABLE_H
+#define __ASM_EXTABLE_H
 /*
  * The exception table consists of pairs of addresses: the first is the
  * address of an instruction that is allowed to fault, and the second is

arch/sparc/include/asm/processor_32.h

@@ -50,16 +50,12 @@ struct thread_struct {
 	unsigned long   fsr;
 	unsigned long   fpqdepth;
 	struct fpq	fpqueue[16];
-	unsigned long flags;
 	mm_segment_t current_ds;
 };
 
-#define SPARC_FLAG_KTHREAD      0x1    /* task is a kernel thread */
-#define SPARC_FLAG_UNALIGNED    0x2    /* is allowed to do unaligned accesses */
-
 #define INIT_THREAD  { \
-	.flags = SPARC_FLAG_KTHREAD, \
 	.current_ds = KERNEL_DS, \
+	.kregs = (struct pt_regs *)(init_stack+THREAD_SIZE)-1 \
 }
 
 /* Do necessary setup to start up a newly executed thread. */

arch/sparc/include/asm/thread_info_64.h

@@ -118,6 +118,7 @@ struct thread_info {
 	.task		=	&tsk,			\
 	.current_ds	=	ASI_P,			\
 	.preempt_count	=	INIT_PREEMPT_COUNT,	\
+	.kregs		=	(struct pt_regs *)(init_stack+THREAD_SIZE)-1 \
 }
 
 /* how to get the thread information struct from C */

arch/sparc/include/asm/uaccess.h

@@ -1,6 +1,9 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef ___ASM_SPARC_UACCESS_H
 #define ___ASM_SPARC_UACCESS_H
+
+#include <asm/extable.h>
+
 #if defined(__sparc__) && defined(__arch64__)
 #include <asm/uaccess_64.h>
 #else

arch/sparc/include/asm/uaccess_32.h

@@ -13,9 +13,6 @@
 
 #include <asm/processor.h>
 
-#define ARCH_HAS_SORT_EXTABLE
-#define ARCH_HAS_SEARCH_EXTABLE
-
 /* Sparc is not segmented, however we need to be able to fool access_ok()
  * when doing system calls from kernel mode legitimately.
  *
@@ -40,36 +37,6 @@
 #define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size)))
 #define access_ok(addr, size) __access_ok((unsigned long)(addr), size)
 
-/*
- * The exception table consists of pairs of addresses: the first is the
- * address of an instruction that is allowed to fault, and the second is
- * the address at which the program should continue.  No registers are
- * modified, so it is entirely up to the continuation code to figure out
- * what to do.
- *
- * All the routines below use bits of fixup code that are out of line
- * with the main instruction path.  This means when everything is well,
- * we don't even have to jump over them.  Further, they do not intrude
- * on our cache or tlb entries.
- *
- * There is a special way how to put a range of potentially faulting
- * insns (like twenty ldd/std's with now intervening other instructions)
- * You specify address of first in insn and 0 in fixup and in the next
- * exception_table_entry you specify last potentially faulting insn + 1
- * and in fixup the routine which should handle the fault.
- * That fixup code will get
- * (faulting_insn_address - first_insn_in_the_range_address)/4
- * in %g2 (ie. index of the faulting instruction in the range).
- */
-
-struct exception_table_entry
-{
-        unsigned long insn, fixup;
-};
-
-/* Returns 0 if exception not found and fixup otherwise.  */
-unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
-
 /* Uh, these should become the main single-value transfer routines..
  * They automatically use the right size if we just have the right
  * pointer type..
@@ -252,12 +219,7 @@ static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 	unsigned long ret;
 
 	__asm__ __volatile__ (
-		".section __ex_table,#alloc\n\t"
-		".align 4\n\t"
-		".word 1f,3\n\t"
-		".previous\n\t"
 		"mov %2, %%o1\n"
-		"1:\n\t"
 		"call __bzero\n\t"
 		" mov %1, %%o0\n\t"
 		"mov %%o0, %0\n"

arch/sparc/include/asm/uaccess_64.h

@@ -10,7 +10,6 @@
 #include <linux/string.h>
 #include <asm/asi.h>
 #include <asm/spitfire.h>
-#include <asm/extable_64.h>
 
 #include <asm/processor.h>
 

arch/sparc/kernel/head_32.S

@@ -515,7 +515,7 @@ continue_boot:
 
 		/* I want a kernel stack NOW! */
 		set	init_thread_union, %g1
-		set	(THREAD_SIZE - STACKFRAME_SZ), %g2
+		set	(THREAD_SIZE - STACKFRAME_SZ - TRACEREG_SZ), %g2
 		add	%g1, %g2, %sp
 		mov	0, %fp			/* And for good luck */
 

arch/sparc/kernel/head_64.S

@@ -706,7 +706,7 @@ tlb_fixup_done:
 	wr	%g0, ASI_P, %asi
 	mov	1, %g1
 	sllx	%g1, THREAD_SHIFT, %g1
-	sub	%g1, (STACKFRAME_SZ + STACK_BIAS), %g1
+	sub	%g1, (STACKFRAME_SZ + STACK_BIAS + TRACEREG_SZ), %g1
 	add	%g6, %g1, %sp
 
 	/* Set per-cpu pointer initially to zero, this makes

arch/sparc/kernel/process_32.c

@@ -216,16 +216,6 @@ void flush_thread(void)
 		clear_thread_flag(TIF_USEDFPU);
 #endif
 	}
-
-	/* This task is no longer a kernel thread. */
-	if (current->thread.flags & SPARC_FLAG_KTHREAD) {
-		current->thread.flags &= ~SPARC_FLAG_KTHREAD;
-
-		/* We must fixup kregs as well. */
-		/* XXX This was not fixed for ti for a while, worked. Unused? */
-		current->thread.kregs = (struct pt_regs *)
-		    (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
-	}
 }
 
 static inline struct sparc_stackf __user *
@@ -313,7 +303,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
 		extern int nwindows;
 		unsigned long psr;
 		memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
-		p->thread.flags |= SPARC_FLAG_KTHREAD;
 		p->thread.current_ds = KERNEL_DS;
 		ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
 		childregs->u_regs[UREG_G1] = sp; /* function */
@@ -325,7 +314,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
 	}
 	memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
 	childregs->u_regs[UREG_FP] = sp;
-	p->thread.flags &= ~SPARC_FLAG_KTHREAD;
 	p->thread.current_ds = USER_DS;
 	ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
 	ti->kpsr = current->thread.fork_kpsr | PSR_PIL;

arch/sparc/kernel/setup_32.c

@@ -266,7 +266,6 @@ static __init void leon_patch(void)
 }
 
 struct tt_entry *sparc_ttable;
-static struct pt_regs fake_swapper_regs;
 
 /* Called from head_32.S - before we have setup anything
  * in the kernel. Be very careful with what you do here.
@@ -363,8 +362,6 @@ void __init setup_arch(char **cmdline_p)
 		(*(linux_dbvec->teach_debugger))();
 	}
 
-	init_task.thread.kregs = &fake_swapper_regs;
-
 	/* Run-time patch instructions to match the cpu model */
 	per_cpu_patch();
 

arch/sparc/kernel/setup_64.c

@@ -165,8 +165,6 @@ extern int root_mountflags;
 
 char reboot_command[COMMAND_LINE_SIZE];
 
-static struct pt_regs fake_swapper_regs = { { 0, }, 0, 0, 0, 0 };
-
 static void __init per_cpu_patch(void)
 {
 	struct cpuid_patch_entry *p;
@@ -661,8 +659,6 @@ void __init setup_arch(char **cmdline_p)
 	rd_image_start = ram_flags & RAMDISK_IMAGE_START_MASK;
 #endif
 
-	task_thread_info(&init_task)->kregs = &fake_swapper_regs;
-
 #ifdef CONFIG_IP_PNP
 	if (!ic_set_manually) {
 		phandle chosen = prom_finddevice("/chosen");

arch/sparc/kernel/unaligned_32.c

@@ -16,6 +16,7 @@
 #include <linux/uaccess.h>
 #include <linux/smp.h>
 #include <linux/perf_event.h>
+#include <linux/extable.h>
 
 #include <asm/setup.h>
 
@@ -213,10 +214,10 @@ static inline int ok_for_kernel(unsigned int insn)
 
 static void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
 {
-	unsigned long g2 = regs->u_regs [UREG_G2];
-	unsigned long fixup = search_extables_range(regs->pc, &g2);
+	const struct exception_table_entry *entry;
 
-	if (!fixup) {
+	entry = search_exception_tables(regs->pc);
+	if (!entry) {
 		unsigned long address = compute_effective_address(regs, insn);
         	if(address < PAGE_SIZE) {
                 	printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference in mna handler");
@@ -232,9 +233,8 @@ static void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
 	        die_if_kernel("Oops", regs);
 		/* Not reached */
 	}
-	regs->pc = fixup;
+	regs->pc = entry->fixup;
 	regs->npc = regs->pc + 4;
-	regs->u_regs [UREG_G2] = g2;
 }
 
 asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
@@ -274,103 +274,9 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
 	}
 }
 
-static inline int ok_for_user(struct pt_regs *regs, unsigned int insn,
-			      enum direction dir)
-{
-	unsigned int reg;
-	int size = ((insn >> 19) & 3) == 3 ? 8 : 4;
-
-	if ((regs->pc | regs->npc) & 3)
-		return 0;
-
-	/* Must access_ok() in all the necessary places. */
-#define WINREG_ADDR(regnum) \
-	((void __user *)(((unsigned long *)regs->u_regs[UREG_FP])+(regnum)))
-
-	reg = (insn >> 25) & 0x1f;
-	if (reg >= 16) {
-		if (!access_ok(WINREG_ADDR(reg - 16), size))
-			return -EFAULT;
-	}
-	reg = (insn >> 14) & 0x1f;
-	if (reg >= 16) {
-		if (!access_ok(WINREG_ADDR(reg - 16), size))
-			return -EFAULT;
-	}
-	if (!(insn & 0x2000)) {
-		reg = (insn & 0x1f);
-		if (reg >= 16) {
-			if (!access_ok(WINREG_ADDR(reg - 16), size))
-				return -EFAULT;
-		}
-	}
-#undef WINREG_ADDR
-	return 0;
-}
-
-static void user_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
+asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
 {
 	send_sig_fault(SIGBUS, BUS_ADRALN,
 		       (void __user *)safe_compute_effective_address(regs, insn),
 		       0, current);
 }
-
-asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
-{
-	enum direction dir;
-
-	if(!(current->thread.flags & SPARC_FLAG_UNALIGNED) ||
-	   (((insn >> 30) & 3) != 3))
-		goto kill_user;
-	dir = decode_direction(insn);
-	if(!ok_for_user(regs, insn, dir)) {
-		goto kill_user;
-	} else {
-		int err, size = decode_access_size(insn);
-		unsigned long addr;
-
-		if(floating_point_load_or_store_p(insn)) {
-			printk("User FPU load/store unaligned unsupported.\n");
-			goto kill_user;
-		}
-
-		addr = compute_effective_address(regs, insn);
-		perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
-		switch(dir) {
-		case load:
-			err = do_int_load(fetch_reg_addr(((insn>>25)&0x1f),
-							 regs),
-					  size, (unsigned long *) addr,
-					  decode_signedness(insn));
-			break;
-
-		case store:
-			err = do_int_store(((insn>>25)&0x1f), size,
-					   (unsigned long *) addr, regs);
-			break;
-
-		case both:
-			/*
-			 * This was supported in 2.4. However, we question
-			 * the value of SWAP instruction across word boundaries.
-			 */
-			printk("Unaligned SWAP unsupported.\n");
-			err = -EFAULT;
-			break;
-
-		default:
-			unaligned_panic("Impossible user unaligned trap.");
-			goto out;
-		}
-		if (err)
-			goto kill_user;
-		else
-			advance(regs);
-		goto out;
-	}
-
-kill_user:
-	user_mna_trap_fault(regs, insn);
-out:
-	;
-}