linux-kernel - Re: [PATCH 03/13] x86/microcode/AMD: Clean up find_equiv

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 18 Jan 2017 00:12:10 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 03/13] x86/microcode/AMD: Clean up find_equiv_id()

On Tue, Jan 17, 2017 at 08:02:59PM +0100, Thomas Gleixner wrote:
> That's how it parses best. The opening brace after the for() tells us: here
> comes a multiline statement. And the inner if (othercond) w/o the opening
> brace tells: here comes a single line statement.
> 
> Reading code/patches very much depends on patterns and structuring. If they
> are consistent the reading flow is undisturbed.

Yeah, very true.

---
From: Borislav Petkov <bp@...e.de>
Date: Sun, 18 Dec 2016 12:05:50 +0100
Subject: [PATCH] x86/microcode/AMD: Clean up find_equiv_id()

No need to have it marked "inline" - let gcc decide. Also, shorten the
argument name and simplify while-test.

While at it, make it into a proper for-loop and simplify it even more,
as tglx suggests.

No functionality change.

Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/kernel/cpu/microcode/amd.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 6a31e2691f3a..5c1509a38048 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -97,20 +97,13 @@ static size_t compute_container_size(u8 *data, u32 total_size)
 	return size;
 }
 
-static inline u16 find_equiv_id(struct equiv_cpu_entry *equiv_cpu_table,
-				unsigned int sig)
+static u16 find_equiv_id(struct equiv_cpu_entry *equiv_table, u32 sig)
 {
-	int i = 0;
-
-	if (!equiv_cpu_table)
-		return 0;
-
-	while (equiv_cpu_table[i].installed_cpu != 0) {
-		if (sig == equiv_cpu_table[i].installed_cpu)
-			return equiv_cpu_table[i].equiv_cpu;
-
-		i++;
+	for (; equiv_table && equiv_table->installed_cpu; equiv_table++) {
+		if (sig == equiv_table->installed_cpu)
+			return equiv_table->equiv_cpu;
 	}
+
 	return 0;
 }
 
-- 
2.11.0

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.