All of lore.kernel.org
 help / color / mirror / Atom feed
From: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
To: Ammar Faizi <ammarfaizi2@gnuweeb.org>,
	Yazen Ghannam <yazen.ghannam@amd.com>
Cc: Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Tony Luck <tony.luck@intel.com>,
	linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
	gwml@vger.gnuweeb.org, x86@kernel.org, stable@vger.kernel.org,
	Alviro Iskandar Setiawan <alviro.iskandar@gmail.com>,
	Jiri Hladky <hladky.jiri@googlemail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v4 2/2] x86/mce/amd: Fix memory leak when `threshold_create_bank()` fails
Date: Thu,  3 Mar 2022 01:58:26 +0000	[thread overview]
Message-ID: <20220303015826.4176416-1-alviro.iskandar@gnuweeb.org> (raw)
In-Reply-To: <109a10da-d1d1-c47a-2f04-31796457f6ff@gnuweeb.org>

On Thu, 3 Mar 2022 06:27:33 +0700, Ammar Faizi wrote:
> +static void _mce_threshold_remove_device(struct threshold_bank **bp)
> +{
> +	unsigned int bank, numbanks = this_cpu_read(mce_num_banks);
> +
> +	for (bank = 0; bank < numbanks; bank++) {
> +		if (bp[bank]) {
> +			threshold_remove_bank(bp[bank]);
> +			bp[bank] = NULL;
> +		}
> +	}
> +	kfree(bp);
> +}

hi sir, i think this can be improved again, we can avoid calling
this_cpu_read(mce_num_banks) twice if we pass the numbanks as an
argument, plz review the changes below

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 9f4b508886dd..e492efab68a2 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -1293,10 +1293,23 @@ static void threshold_remove_bank(struct threshold_bank *bank)
 	kfree(bank);
 }
 
+static void _mce_threshold_remove_device(struct threshold_bank **bp,
+					 unsigned int numbanks)
+{
+	unsigned int bank;
+
+	for (bank = 0; bank < numbanks; bank++) {
+		if (bp[bank]) {
+			threshold_remove_bank(bp[bank]);
+			bp[bank] = NULL;
+		}
+	}
+	kfree(bp);
+}
+
 int mce_threshold_remove_device(unsigned int cpu)
 {
 	struct threshold_bank **bp = this_cpu_read(threshold_banks);
-	unsigned int bank, numbanks = this_cpu_read(mce_num_banks);
 
 	if (!bp)
 		return 0;
@@ -1307,13 +1320,7 @@ int mce_threshold_remove_device(unsigned int cpu)
 	 */
 	this_cpu_write(threshold_banks, NULL);
 
-	for (bank = 0; bank < numbanks; bank++) {
-		if (bp[bank]) {
-			threshold_remove_bank(bp[bank]);
-			bp[bank] = NULL;
-		}
-	}
-	kfree(bp);
+	_mce_threshold_remove_device(bp, this_cpu_read(mce_num_banks));
 	return 0;
 }
 
@@ -1350,15 +1357,14 @@ int mce_threshold_create_device(unsigned int cpu)
 		if (!(this_cpu_read(bank_map) & (1 << bank)))
 			continue;
 		err = threshold_create_bank(bp, cpu, bank);
-		if (err)
-			goto out_err;
+		if (err) {
+			_mce_threshold_remove_device(bp, numbanks);
+			return err;
+		}
 	}
 	this_cpu_write(threshold_banks, bp);
 
 	if (thresholding_irq_en)
 		mce_threshold_vector = amd_threshold_interrupt;
 	return 0;
-out_err:
-	mce_threshold_remove_device(cpu);
-	return err;
 }

-- Viro

  reply	other threads:[~2022-03-03  1:58 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-01  9:46 [PATCH v4 0/2] Two x86 fixes Ammar Faizi
2022-03-01  9:46 ` [PATCH v4 1/2] x86/delay: Fix the wrong asm constraint in `delay_loop()` Ammar Faizi
2022-03-01  9:54   ` David Laight
2022-03-03  0:14     ` Ammar Faizi
2022-03-01 11:33   ` Alviro Iskandar Setiawan
2022-03-03  0:06     ` Ammar Faizi
2022-03-03  0:35     ` David Laight
2022-03-01  9:46 ` [PATCH v4 2/2] x86/mce/amd: Fix memory leak when `threshold_create_bank()` fails Ammar Faizi
2022-03-02 17:26   ` Yazen Ghannam
2022-03-02 23:20     ` Ammar Faizi
2022-03-02 23:27       ` Ammar Faizi
2022-03-03  1:58         ` Alviro Iskandar Setiawan [this message]
2022-03-03  2:07           ` Ammar Faizi
2022-03-03  2:32             ` Ammar Faizi
2022-03-03  2:51               ` Alviro Iskandar Setiawan
2022-03-07  0:27               ` Ammar Faizi
2022-03-09 20:55                 ` Yazen Ghannam
2022-03-10  1:56                   ` Ammar Faizi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220303015826.4176416-1-alviro.iskandar@gnuweeb.org \
    --to=alviro.iskandar@gnuweeb.org \
    --cc=alviro.iskandar@gmail.com \
    --cc=ammarfaizi2@gnuweeb.org \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=gwml@vger.gnuweeb.org \
    --cc=hladky.jiri@googlemail.com \
    --cc=hpa@zytor.com \
    --cc=linux-edac@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=stable@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=tony.luck@intel.com \
    --cc=x86@kernel.org \
    --cc=yazen.ghannam@amd.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.