linux-kernel - Re: [PATCH 2/3] ACPI, APEI, EINJ: Refactor available_error_type

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:   Tue, 20 Sep 2022 11:26:06 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Jay Lu <jaylu102@....com>
Cc:     linux-kernel@...r.kernel.org, rafael@...nel.org, lenb@...nel.org,
        james.morse@....com, tony.luck@...el.com,
        dave.hansen@...ux.intel.com, jarkko@...nel.org,
        xueshuai@...ux.alibaba.com, terry.bowman@....com,
        yazen.ghannam@....com, smita.koralahallichannabasappa@....com,
        robert.richter@....com, linux-acpi@...r.kernel.org,
        jayakumar.govindankalivu@....com
Subject: Re: [PATCH 2/3] ACPI, APEI, EINJ: Refactor available_error_type_show

On Fri, Jul 29, 2022 at 10:35:49AM -0500, Jay Lu wrote:
> Move error type descriptions into an array and loop over error types
> to improve readability and maintainability.
> 
> Replace seq_printf() with seq_puts() as recommended by checkpatch.pl.
> 
> Signed-off-by: Jay Lu <jaylu102@....com>
> ---
>  drivers/acpi/apei/einj.c | 41 +++++++++++++++++-----------------------
>  1 file changed, 17 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
> index da039c630fd0..a68103280f74 100644
> --- a/drivers/acpi/apei/einj.c
> +++ b/drivers/acpi/apei/einj.c
> @@ -569,6 +569,20 @@ static u64 error_param2;
>  static u64 error_param3;
>  static u64 error_param4;
>  static struct dentry *einj_debug_dir;
> +static const char * const einj_error_type_string[] = {
> +	"0x00000001\tProcessor Correctable\n",                          /* bit 0  */
> +	"0x00000002\tProcessor Uncorrectable non-fatal\n",              /* bit 1  */
> +	"0x00000004\tProcessor Uncorrectable fatal\n",                  /* bit 2  */
> +	"0x00000008\tMemory Correctable\n",                             /* bit 3  */
> +	"0x00000010\tMemory Uncorrectable non-fatal\n",                 /* bit 4  */
> +	"0x00000020\tMemory Uncorrectable fatal\n",                     /* bit 5  */
> +	"0x00000040\tPCI Express Correctable\n",                        /* bit 6  */
> +	"0x00000080\tPCI Express Uncorrectable non-fatal\n",            /* bit 7  */
> +	"0x00000100\tPCI Express Uncorrectable fatal\n",                /* bit 8  */
> +	"0x00000200\tPlatform Correctable\n",                           /* bit 9  */
> +	"0x00000400\tPlatform Uncorrectable non-fatal\n",               /* bit 10 */
> +	"0x00000800\tPlatform Uncorrectable fatal\n",                   /* bit 11 */
									^^^^^^^^^^^^

Those comments look useless - you have the bit numbers in front already.


>  static int available_error_type_show(struct seq_file *m, void *v)
>  {
> @@ -578,30 +592,9 @@ static int available_error_type_show(struct seq_file *m, void *v)
>  	rc = einj_get_available_error_type(&available_error_type);
>  	if (rc)
>  		return rc;
> -	if (available_error_type & 0x0001)
> -		seq_printf(m, "0x00000001\tProcessor Correctable\n");
> -	if (available_error_type & 0x0002)
> -		seq_printf(m, "0x00000002\tProcessor Uncorrectable non-fatal\n");
> -	if (available_error_type & 0x0004)
> -		seq_printf(m, "0x00000004\tProcessor Uncorrectable fatal\n");
> -	if (available_error_type & 0x0008)
> -		seq_printf(m, "0x00000008\tMemory Correctable\n");
> -	if (available_error_type & 0x0010)
> -		seq_printf(m, "0x00000010\tMemory Uncorrectable non-fatal\n");
> -	if (available_error_type & 0x0020)
> -		seq_printf(m, "0x00000020\tMemory Uncorrectable fatal\n");
> -	if (available_error_type & 0x0040)
> -		seq_printf(m, "0x00000040\tPCI Express Correctable\n");
> -	if (available_error_type & 0x0080)
> -		seq_printf(m, "0x00000080\tPCI Express Uncorrectable non-fatal\n");
> -	if (available_error_type & 0x0100)
> -		seq_printf(m, "0x00000100\tPCI Express Uncorrectable fatal\n");
> -	if (available_error_type & 0x0200)
> -		seq_printf(m, "0x00000200\tPlatform Correctable\n");
> -	if (available_error_type & 0x0400)
> -		seq_printf(m, "0x00000400\tPlatform Uncorrectable non-fatal\n");
> -	if (available_error_type & 0x0800)
> -		seq_printf(m, "0x00000800\tPlatform Uncorrectable fatal\n");
> +	for (int pos = 0; pos < ARRAY_SIZE(einj_error_type_string); pos++)
> +		if (available_error_type & (BIT(0) << pos))
					   ^^^^^^^^^^^^^^^

That's a weird way of saying:

	BIT(pos)

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette