linux-kernel - [PATCH v6 05/17] arm64: hibernate: remove gotos as they are not needed

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Date:   Fri,  4 Oct 2019 14:52:22 -0400
From:   Pavel Tatashin <pasha.tatashin@...een.com>
To:     pasha.tatashin@...een.com, jmorris@...ei.org, sashal@...nel.org,
        ebiederm@...ssion.com, kexec@...ts.infradead.org,
        linux-kernel@...r.kernel.org, corbet@....net,
        catalin.marinas@....com, will@...nel.org,
        linux-arm-kernel@...ts.infradead.org, marc.zyngier@....com,
        james.morse@....com, vladimir.murzin@....com,
        matthias.bgg@...il.com, bhsharma@...hat.com, linux-mm@...ck.org,
        mark.rutland@....com
Subject: [PATCH v6 05/17] arm64: hibernate: remove gotos as they are not needed

Usually, gotos are used to handle cleanup after exception, but in case of
create_safe_exec_page and swsusp_arch_resume there are no clean-ups. So,
simply return the errors directly.

Signed-off-by: Pavel Tatashin <pasha.tatashin@...een.com>
Reviewed-by: James Morse <james.morse@....com>
---
 arch/arm64/kernel/hibernate.c | 49 ++++++++++++-----------------------
 1 file changed, 17 insertions(+), 32 deletions(-)

diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 34297716643f..83c41a2f8400 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -198,7 +198,6 @@ static int create_safe_exec_page(void *src_start, size_t length,
 				 unsigned long dst_addr,
 				 phys_addr_t *phys_dst_addr)
 {
-	int rc = 0;
 	pgd_t *trans_pgd;
 	pgd_t *pgdp;
 	pud_t *pudp;
@@ -206,47 +205,37 @@ static int create_safe_exec_page(void *src_start, size_t length,
 	pte_t *ptep;
 	unsigned long dst = get_safe_page(GFP_ATOMIC);
 
-	if (!dst) {
-		rc = -ENOMEM;
-		goto out;
-	}
+	if (!dst)
+		return -ENOMEM;
 
 	memcpy((void *)dst, src_start, length);
 	__flush_icache_range(dst, dst + length);
 
 	trans_pgd = (void *)get_safe_page(GFP_ATOMIC);
-	if (!trans_pgd) {
-		rc = -ENOMEM;
-		goto out;
-	}
+	if (!trans_pgd)
+		return -ENOMEM;
 
 	pgdp = pgd_offset_raw(trans_pgd, dst_addr);
 	if (pgd_none(READ_ONCE(*pgdp))) {
 		pudp = (void *)get_safe_page(GFP_ATOMIC);
-		if (!pudp) {
-			rc = -ENOMEM;
-			goto out;
-		}
+		if (!pudp)
+			return -ENOMEM;
 		pgd_populate(&init_mm, pgdp, pudp);
 	}
 
 	pudp = pud_offset(pgdp, dst_addr);
 	if (pud_none(READ_ONCE(*pudp))) {
 		pmdp = (void *)get_safe_page(GFP_ATOMIC);
-		if (!pmdp) {
-			rc = -ENOMEM;
-			goto out;
-		}
+		if (!pmdp)
+			return -ENOMEM;
 		pud_populate(&init_mm, pudp, pmdp);
 	}
 
 	pmdp = pmd_offset(pudp, dst_addr);
 	if (pmd_none(READ_ONCE(*pmdp))) {
 		ptep = (void *)get_safe_page(GFP_ATOMIC);
-		if (!ptep) {
-			rc = -ENOMEM;
-			goto out;
-		}
+		if (!ptep)
+			return -ENOMEM;
 		pmd_populate_kernel(&init_mm, pmdp, ptep);
 	}
 
@@ -272,8 +261,7 @@ static int create_safe_exec_page(void *src_start, size_t length,
 
 	*phys_dst_addr = virt_to_phys((void *)dst);
 
-out:
-	return rc;
+	return 0;
 }
 
 #define dcache_clean_range(start, end)	__flush_dcache_area(start, (end - start))
@@ -482,7 +470,7 @@ static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start,
  */
 int swsusp_arch_resume(void)
 {
-	int rc = 0;
+	int rc;
 	void *zero_page;
 	size_t exit_size;
 	pgd_t *tmp_pg_dir;
@@ -498,12 +486,11 @@ int swsusp_arch_resume(void)
 	tmp_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
 	if (!tmp_pg_dir) {
 		pr_err("Failed to allocate memory for temporary page tables.\n");
-		rc = -ENOMEM;
-		goto out;
+		return -ENOMEM;
 	}
 	rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, PAGE_END);
 	if (rc)
-		goto out;
+		return rc;
 
 	/*
 	 * We need a zero page that is zero before & after resume in order to
@@ -512,8 +499,7 @@ int swsusp_arch_resume(void)
 	zero_page = (void *)get_safe_page(GFP_ATOMIC);
 	if (!zero_page) {
 		pr_err("Failed to allocate zero page.\n");
-		rc = -ENOMEM;
-		goto out;
+		return -ENOMEM;
 	}
 
 	/*
@@ -531,7 +517,7 @@ int swsusp_arch_resume(void)
 				   &phys_hibernate_exit);
 	if (rc) {
 		pr_err("Failed to create safe executable page for hibernate_exit code.\n");
-		goto out;
+		return rc;
 	}
 
 	/*
@@ -558,8 +544,7 @@ int swsusp_arch_resume(void)
 		       resume_hdr.reenter_kernel, restore_pblist,
 		       resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page));
 
-out:
-	return rc;
+	return 0;
 }
 
 int hibernate_resume_nonboot_cpu_disable(void)
-- 
2.23.0