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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@lists.ozlabs.org
Cc: aneesh.kumar@linux.vnet.ibm.com,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: [PATCH 11/24] powerpc/mm: Simplify returns from __do_page_fault
Date: Wed, 19 Jul 2017 14:49:33 +1000	[thread overview]
Message-ID: <20170719044946.22030-11-benh@kernel.crashing.org> (raw)
In-Reply-To: <20170719044946.22030-1-benh@kernel.crashing.org>

Now that we moved the exception state handling to a wrapper, we can
just directly return rather than "goto bail"

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/mm/fault.c | 39 ++++++++++++++++-----------------------
 1 file changed, 16 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 2f825ae68f20..e8d6acc888c5 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -233,39 +233,36 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
 	if (error_code & ICSWX_DSI_UCT) {
 		rc = acop_handle_fault(regs, address, error_code);
 		if (rc)
-			goto bail;
+			return rc;
 	}
 #endif /* CONFIG_PPC_ICSWX */
 
 	if (notify_page_fault(regs))
-		goto bail;
+		return 0;
 
 	if (unlikely(page_fault_is_bad(error_code))) {
-		if (is_user)
+		if (is_user) {
 			_exception(SIGBUS, regs, BUS_OBJERR, address);
-		else
-			rc = SIGBUS;
-		goto bail;
+			return 0;
+		}
+		return SIGBUS;
 	}
 
 	/*
 	 * The kernel should never take an execute fault nor should it
 	 * take a page fault to a kernel address.
 	 */
-	if (!is_user && (is_exec || (address >= TASK_SIZE))) {
-		rc = SIGSEGV;
-		goto bail;
-	}
+	if (!is_user && (is_exec || (address >= TASK_SIZE)))
+		return SIGSEGV;
 
 	/* We restore the interrupt state now */
 	if (!arch_irq_disabled_regs(regs))
 		local_irq_enable();
 
 	if (faulthandler_disabled() || mm == NULL) {
-		if (!is_user) {
-			rc = SIGSEGV;
-			goto bail;
-		}
+		if (!is_user)
+			return SIGSEGV;
+
 		/* faulthandler_disabled() in user mode is really bad,
 		   as is current->mm == NULL. */
 		printk(KERN_EMERG "Page fault in user mode with "
@@ -454,9 +451,8 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
 			goto bad_area_nosemaphore;
 		rc = mm_fault_error(regs, address, fault);
 		if (rc >= MM_FAULT_RETURN)
-			goto bail;
-		else
-			rc = 0;
+			return rc;
+		rc = 0;
 	}
 
 	/*
@@ -483,7 +479,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
 			      regs, address);
 	}
 
-	goto bail;
+	return rc;
 
 bad_area:
 	up_read(&mm->mmap_sem);
@@ -492,7 +488,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
 	/* User mode accesses cause a SIGSEGV */
 	if (is_user) {
 		_exception(SIGSEGV, regs, code, address);
-		goto bail;
+		return 0;
 	}
 
 	if (is_exec && (error_code & DSISR_PROTFAULT))
@@ -500,10 +496,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
 				   " page (%lx) - exploit attempt? (uid: %d)\n",
 				   address, from_kuid(&init_user_ns, current_uid()));
 
-	rc = SIGSEGV;
-
-bail:
-	return rc;
+	return SIGSEGV;
 }
 NOKPROBE_SYMBOL(__do_page_fault);
 
-- 
2.13.3

  parent reply	other threads:[~2017-07-19  4:50 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-19  4:49 [PATCH 01/24] powerpc/mm: Move exception_enter/exit to a do_page_fault wrapper Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 02/24] powerpc/mm: Pre-filter SRR1 bits before do_page_fault() Benjamin Herrenschmidt
2017-07-22 16:43   ` LEROY Christophe
2017-07-23  1:10     ` Benjamin Herrenschmidt
2017-07-24 13:48     ` Michael Ellerman
2017-07-19  4:49 ` [PATCH 03/24] powerpc/6xx: Handle DABR match before calling do_page_fault Benjamin Herrenschmidt
2017-08-03  0:19   ` Michael Ellerman
2017-08-03  1:00     ` Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 04/24] powerpc/mm: Update definitions of DSISR bits Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 05/24] powerpc/mm: Update bits used to skip hash_page Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 06/24] powerpc/mm: Use symbolic constants for filtering SRR1 bits on ISIs Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 07/24] powerpc/mm: Move out definition of CPU specific is_write bits Benjamin Herrenschmidt
2017-07-22 16:40   ` LEROY Christophe
2017-07-23  1:06     ` Benjamin Herrenschmidt
2017-07-24 11:58     ` Michael Ellerman
2017-07-19  4:49 ` [PATCH 08/24] powerpc/mm: Move error_code checks for bad faults earlier Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 09/24] powerpc/mm: Overhaul handling of bad page faults Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 10/24] powerpc/mm: Move debugger check to notify_page_fault() Benjamin Herrenschmidt
2017-07-19  4:49 ` Benjamin Herrenschmidt [this message]
2017-07-19  4:49 ` [PATCH 12/24] powerpc/mm: Fix reporting of kernel execute faults Benjamin Herrenschmidt
2018-11-07  8:35   ` Christophe LEROY
2018-11-07 10:39     ` Benjamin Herrenschmidt
     [not found]     ` <87zhtr5d1v.fsf@linux.ibm.com>
2018-11-30  6:08       ` Christophe LEROY
2017-07-19  4:49 ` [PATCH 13/24] powerpc/mm: Make bad_area* helper functions Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 14/24] powerpc/mm: Rework mm_fault_error() Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 15/24] powerpc/mm: Move CMO accounting out of do_page_fault into a helper Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 16/24] powerpc/mm: Cosmetic fix to page fault accounting Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 17/24] powerpc/mm: Move the DSISR_PROTFAULT sanity check Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 18/24] powerpc/mm: Move/simplify faulthandler_disabled() and !mm check Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 19/24] powerpc/mm: Add a bunch of (un)likely annotations to do_page_fault Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 20/24] powerpc/mm: Set fault flags earlier Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 21/24] powerpc/mm: Move page fault VMA access checks to a helper Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 22/24] powerpc/mm: Don't lose "major" fault indication on retry Benjamin Herrenschmidt
2017-07-19  4:49 ` [PATCH 23/24] powerpc/mm: Cleanup check for stack expansion Benjamin Herrenschmidt
2017-07-21 16:59   ` LEROY Christophe
2017-07-24 10:47     ` Michael Ellerman
2017-07-24 17:34       ` LEROY Christophe
2017-07-25 11:19         ` Michael Ellerman
2017-07-31 11:37           ` Christophe LEROY
2017-07-19  4:49 ` [PATCH 24/24] powerpc: Remove old unused icswx based coprocessor support Benjamin Herrenschmidt
2017-08-07 10:41 ` [01/24] powerpc/mm: Move exception_enter/exit to a do_page_fault wrapper Michael Ellerman
2017-08-07 16:37   ` Christophe LEROY
2017-08-08  2:16     ` Michael Ellerman
2017-08-08  6:45       ` Christophe LEROY
2017-08-08 10:00         ` Michael Ellerman

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