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From:   Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To:     Bjorn Helgaas <bhelgaas@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>
Cc:     linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        linux-pci@vger.kernel.org
Subject: [PATCH 2/2] x86/PCI: Slightly simplify pirq_convert_irt_table()
Date:   Sat,  6 May 2023 09:11:10 +0200
Message-Id: <84bf047b01452a72642dbe355b02ef016c985a91.1683356951.git.christophe.jaillet@wanadoo.fr>
In-Reply-To: <bc8422a8bf3ff99809413eb62dd12aacc85a9950.1683356951.git.christophe.jaillet@wanadoo.fr>
References: <bc8422a8bf3ff99809413eb62dd12aacc85a9950.1683356951.git.christophe.jaillet@wanadoo.fr>
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'size' if computed twice. *ir and *it being the same, the result is the
same as well.

While at it, also use struct_size() which is less verbose, more robust and
more informative.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 arch/x86/pci/irq.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index e29b487cc069..6bc51f80eec2 100644
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -140,14 +140,13 @@ static inline struct irq_routing_table *pirq_convert_irt_table(u8 *addr,
 	if (ir->signature != IRT_SIGNATURE || !ir->used || entries < ir->used)
 		return NULL;
 
-	size = sizeof(*ir) + ir->used * sizeof(ir->slots[0]);
+	size = struct_size(ir, slots, ir->used);
 	if (size > limit - addr)
 		return NULL;
 
 	DBG(KERN_DEBUG "PCI: $IRT Interrupt Routing Table found at 0x%lx\n",
 	    __pa(ir));
 
-	size = sizeof(*rt) + ir->used * sizeof(rt->slots[0]);
 	rt = kzalloc(size, GFP_KERNEL);
 	if (!rt)
 		return NULL;
-- 
2.34.1