Thread (24 messages) 24 messages, 2 authors, 2021-01-03
STALE2020d

[PATCH v4 04/21] powerpc: bad_page_fault, do_break get registers from regs

From: Nicholas Piggin <npiggin@gmail.com>
Date: 2021-01-02 12:38:35
Subsystem: linux for powerpc (32-bit and 64-bit), linux for powerpc embedded ppc8xx and ppc83xx, the rest · Maintainers: Madhavan Srinivasan, Michael Ellerman, Christophe Leroy, Linus Torvalds

Similar to the previous patch this makes interrupt handler function
types more regular so they can be wrapped with the next patch.

bad_page_fault and do_break are not performance critical.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/bug.h             |  4 ++--
 arch/powerpc/include/asm/debug.h           |  3 +--
 arch/powerpc/kernel/entry_32.S             |  3 +--
 arch/powerpc/kernel/exceptions-64e.S       |  3 +--
 arch/powerpc/kernel/exceptions-64s.S       |  3 +--
 arch/powerpc/kernel/head_8xx.S             |  5 ++---
 arch/powerpc/kernel/process.c              |  7 +++----
 arch/powerpc/kernel/traps.c                |  2 +-
 arch/powerpc/mm/book3s64/hash_utils.c      |  4 ++--
 arch/powerpc/mm/book3s64/slb.c             |  2 +-
 arch/powerpc/mm/fault.c                    | 10 +++++-----
 arch/powerpc/platforms/8xx/machine_check.c |  2 +-
 12 files changed, 21 insertions(+), 27 deletions(-)
diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
index f7827e993196..4220789b9a97 100644
--- a/arch/powerpc/include/asm/bug.h
+++ b/arch/powerpc/include/asm/bug.h
@@ -112,8 +112,8 @@
 
 struct pt_regs;
 long do_page_fault(struct pt_regs *);
-extern void bad_page_fault(struct pt_regs *, unsigned long, int);
-void __bad_page_fault(struct pt_regs *regs, unsigned long address, int sig);
+void bad_page_fault(struct pt_regs *, int);
+void __bad_page_fault(struct pt_regs *regs, int sig);
 extern void _exception(int, struct pt_regs *, int, unsigned long);
 extern void _exception_pkey(struct pt_regs *, unsigned long, int);
 extern void die(const char *, struct pt_regs *, long);
diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
index ec57daf87f40..0550eceab3ca 100644
--- a/arch/powerpc/include/asm/debug.h
+++ b/arch/powerpc/include/asm/debug.h
@@ -52,8 +52,7 @@ extern void do_send_trap(struct pt_regs *regs, unsigned long address,
 			 unsigned long error_code, int brkpt);
 #else
 
-extern void do_break(struct pt_regs *regs, unsigned long address,
-		     unsigned long error_code);
+void do_break(struct pt_regs *regs);
 #endif
 
 #endif /* _ASM_POWERPC_DEBUG_H */
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index a32157ce0551..a94127eed56b 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -673,9 +673,8 @@ handle_page_fault:
 	lwz	r0,_TRAP(r1)
 	clrrwi	r0,r0,1
 	stw	r0,_TRAP(r1)
-	mr	r5,r3
+	mr	r4,r3		/* err arg for bad_page_fault */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	lwz	r4,_DAR(r1)
 	bl	__bad_page_fault
 	b	ret_from_except_full
 
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 43e71d86dcbf..52421042a020 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -1018,9 +1018,8 @@ storage_fault_common:
 	bne-	1f
 	b	ret_from_except_lite
 1:	bl	save_nvgprs
-	mr	r5,r3
+	mr	r4,r3
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	ld	r4,_DAR(r1)
 	bl	__bad_page_fault
 	b	ret_from_except
 
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index d42ee713a753..19374b7e5073 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2136,8 +2136,7 @@ EXC_COMMON_BEGIN(h_data_storage_common)
 	GEN_COMMON h_data_storage
 	addi    r3,r1,STACK_FRAME_OVERHEAD
 BEGIN_MMU_FTR_SECTION
-	ld	r4,_DAR(r1)
-	li	r5,SIGSEGV
+	li	r4,SIGSEGV
 	bl      bad_page_fault
 MMU_FTR_SECTION_ELSE
 	bl      unknown_exception
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 0b2c247cfdff..7869db974185 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -364,10 +364,9 @@ do_databreakpoint:
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	mfspr	r4,SPRN_BAR
 	stw	r4,_DAR(r11)
-#ifdef CONFIG_VMAP_STACK
-	lwz	r5,_DSISR(r11)
-#else
+#ifndef CONFIG_VMAP_STACK
 	mfspr	r5,SPRN_DSISR
+	stw	r5,_DSISR(r11)
 #endif
 	EXC_XFER_STD(0x1c00, do_break)
 
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index a66f435dabbf..4f0f81e9420b 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -659,11 +659,10 @@ static void do_break_handler(struct pt_regs *regs)
 	}
 }
 
-void do_break (struct pt_regs *regs, unsigned long address,
-		    unsigned long error_code)
+void do_break(struct pt_regs *regs)
 {
 	current->thread.trap_nr = TRAP_HWBKPT;
-	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr,
 			11, SIGSEGV) == NOTIFY_STOP)
 		return;
 
@@ -681,7 +680,7 @@ void do_break (struct pt_regs *regs, unsigned long address,
 		do_break_handler(regs);
 
 	/* Deliver the signal to userspace */
-	force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)address);
+	force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar);
 }
 #endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 3ec7b443fe6b..f3f6af3141ee 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1612,7 +1612,7 @@ void alignment_exception(struct pt_regs *regs)
 	if (user_mode(regs))
 		_exception(sig, regs, code, regs->dar);
 	else
-		bad_page_fault(regs, regs->dar, sig);
+		bad_page_fault(regs, sig);
 
 bail:
 	exception_exit(prev_state);
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 8d014924ee0d..77073a256cff 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1539,7 +1539,7 @@ long do_hash_fault(struct pt_regs *regs)
 	 * the access, or panic if there isn't a handler.
 	 */
 	if (unlikely(in_nmi())) {
-		bad_page_fault(regs, ea, SIGSEGV);
+		bad_page_fault(regs, SIGSEGV);
 		return 0;
 	}
 
@@ -1578,7 +1578,7 @@ long do_hash_fault(struct pt_regs *regs)
 			else
 				_exception(SIGBUS, regs, BUS_ADRERR, ea);
 		} else {
-			bad_page_fault(regs, ea, SIGBUS);
+			bad_page_fault(regs, SIGBUS);
 		}
 		err = 0;
 
diff --git a/arch/powerpc/mm/book3s64/slb.c b/arch/powerpc/mm/book3s64/slb.c
index 985902ce0272..c581548b533f 100644
--- a/arch/powerpc/mm/book3s64/slb.c
+++ b/arch/powerpc/mm/book3s64/slb.c
@@ -874,7 +874,7 @@ void do_bad_slb_fault(struct pt_regs *regs)
 		if (user_mode(regs))
 			_exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar);
 		else
-			bad_page_fault(regs, regs->dar, SIGSEGV);
+			bad_page_fault(regs, SIGSEGV);
 	} else if (err == -EINVAL) {
 		unrecoverable_exception(regs);
 	} else {
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 0e7f61fa65f9..357236fd43dc 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -568,14 +568,14 @@ static long __do_page_fault(struct pt_regs *regs)
 	/* 32 and 64e handle these errors in asm */
 	if (unlikely(err)) {
 		if (err > 0) {
-			__bad_page_fault(regs, address, err);
+			__bad_page_fault(regs, err);
 			err = 0;
 		} else {
 			/*
 			 * do_break() may change NV GPRS while handling the
 			 * breakpoint. Return -ve to caller to do that.
 			 */
-			do_break(regs, address, error_code);
+			do_break(regs);
 		}
 	}
 #endif
@@ -602,7 +602,7 @@ NOKPROBE_SYMBOL(do_page_fault);
  * It is called from the DSI and ISI handlers in head.S and from some
  * of the procedures in traps.c.
  */
-void __bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
+void __bad_page_fault(struct pt_regs *regs, int sig)
 {
 	int is_write = page_fault_is_write(regs->dsisr);
 
@@ -640,7 +640,7 @@ void __bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
 	die("Kernel access of bad area", regs, sig);
 }
 
-void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
+void bad_page_fault(struct pt_regs *regs, int sig)
 {
 	const struct exception_table_entry *entry;
 
@@ -649,5 +649,5 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
 	if (entry)
 		instruction_pointer_set(regs, extable_fixup(entry));
 	else
-		__bad_page_fault(regs, address, sig);
+		__bad_page_fault(regs, sig);
 }
diff --git a/arch/powerpc/platforms/8xx/machine_check.c b/arch/powerpc/platforms/8xx/machine_check.c
index 88dedf38eccd..656365975895 100644
--- a/arch/powerpc/platforms/8xx/machine_check.c
+++ b/arch/powerpc/platforms/8xx/machine_check.c
@@ -26,7 +26,7 @@ int machine_check_8xx(struct pt_regs *regs)
 	 * to deal with that than having a wart in the mcheck handler.
 	 * -- BenH
 	 */
-	bad_page_fault(regs, regs->dar, SIGBUS);
+	bad_page_fault(regs, SIGBUS);
 	return 1;
 #else
 	return 0;
-- 
2.23.0
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