linux-kernel - [PATCH 03/11] efi/fdt: Simplify get

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Message-Id: <20181129171230.18699-4-ard.biesheuvel@linaro.org>
Date:   Thu, 29 Nov 2018 18:12:22 +0100
From:   Ard Biesheuvel <ard.biesheuvel@...aro.org>
To:     linux-efi@...r.kernel.org, Ingo Molnar <mingo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        linux-kernel@...r.kernel.org, Andy Lutomirski <luto@...nel.org>,
        Arend van Spriel <arend.vanspriel@...adcom.com>,
        Bhupesh Sharma <bhsharma@...hat.com>,
        Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...el.com>,
        Eric Snowberg <eric.snowberg@...cle.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Joe Perches <joe@...ches.com>,
        Jon Hunter <jonathanh@...dia.com>,
        Julien Thierry <julien.thierry@....com>,
        Marc Zyngier <marc.zyngier@....com>,
        Nathan Chancellor <natechancellor@...il.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Sai Praneeth Prakhya <sai.praneeth.prakhya@...el.com>,
        Sedat Dilek <sedat.dilek@...il.com>,
        YiFei Zhu <zhuyifei1999@...il.com>
Subject: [PATCH 03/11] efi/fdt: Simplify get_fdt flow

From: Julien Thierry <julien.thierry@....com>

Reorganize get_fdt lookup loop, clearly showing that:
- Nothing is done for table entries that do not have fdt_guid
- Once an entry with fdt_guid is found, break out of the loop

No functional changes.

Suggested-by: Joe Perches <joe@...ches.com>
Signed-off-by: Julien Thierry <julien.thierry@....com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
---
 drivers/firmware/efi/libstub/fdt.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index a3614f9b5f75..0dc7b4987cc2 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -370,23 +370,24 @@ void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size)
 {
 	efi_guid_t fdt_guid = DEVICE_TREE_GUID;
 	efi_config_table_t *tables;
-	void *fdt;
 	int i;
 
-	tables = (efi_config_table_t *) sys_table->tables;
-	fdt = NULL;
+	tables = (efi_config_table_t *)sys_table->tables;
 
 	for (i = 0; i < sys_table->nr_tables; i++) {
-		if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) {
-			fdt = (void *) tables[i].table;
-			if (fdt_check_header(fdt) != 0) {
-				pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n");
-				return NULL;
-			}
-			*fdt_size = fdt_totalsize(fdt);
-			break;
+		void *fdt;
+
+		if (efi_guidcmp(tables[i].guid, fdt_guid) != 0)
+			continue;
+
+		fdt = (void *)tables[i].table;
+		if (fdt_check_header(fdt) != 0) {
+			pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n");
+			return NULL;
 		}
+		*fdt_size = fdt_totalsize(fdt);
+		return fdt;
 	}
 
-	return fdt;
+	return NULL;
 }
-- 
2.19.1