linux-kernel - [PATCH v2] EFI loader: remove redundant code

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Date:   Wed, 2 Nov 2016 07:18:55 +0300
From:   Eugene Korenevsky <ekorenevsky@...il.com>
To:     linux-kernel@...r.kernel.org, linux-efi@...r.kernel.org
Cc:     Matt Fleming <matt@...eblueprint.co.uk>,
        Linn Crosetto <linn@....com>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>
Subject: [PATCH v2] EFI loader: remove redundant code

*e820ext is always NULL in 'alloc_e820ext()' (see the code of 'exit_boot()').
Without loss of generality we can replace freeing with returning
EFI_INVALID_PARAMETER. So if the caller would ever incorrectly pass non-NULL
*e820ext, he will obtain a returned error code.

---
 arch/x86/boot/compressed/eboot.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index cc69e37..6cc66c7 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -956,11 +956,8 @@ static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
 	size = sizeof(struct setup_data) +
 		sizeof(struct e820entry) * nr_desc;
 
-	if (*e820ext) {
-		efi_call_early(free_pool, *e820ext);
-		*e820ext = NULL;
-		*e820ext_size = 0;
-	}
+	if (*e820ext)
+		return EFI_INVALID_PARAMETER;
 
 	status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
 				size, (void **)e820ext);
-- 
2.10.2