Re: [PATCH v4 1/2] efi/cper: add cper_mem_err_status_str to decode error description

Borislav Petkov
2022-01-25T19:09:04Z

On Tue, Jan 25, 2022 at 10:49:38AM +0800, Shuai Xue wrote:
> Introduce a new helper function cper_mem_err_status_str() which is used to
> decode the description of error status, and the cper_print_mem() will call
> it and report the details of error status.
>
> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
> ---
> drivers/firmware/efi/cper.c | 29 ++++++++++++++++++++++++++++-
> include/linux/cper.h | 1 +
> 2 files changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
> index 6ec8edec6329..7f08d4ea906e 100644
> --- a/drivers/firmware/efi/cper.c
> +++ b/drivers/firmware/efi/cper.c
> @@ -211,6 +211,31 @@ const char *cper_mem_err_type_str(unsigned int etype)
> }
> EXPORT_SYMBOL_GPL(cper_mem_err_type_str);
>
> +const char *cper_mem_err_status_str(u64 status)
> +{
> + switch ((status >> 8) & 0xff) {
> + case 1: return "Error detected internal to the component";
> + case 4: return "Storage error in DRAM memory";
> + case 5: return "Storage error in TLB";
> + case 6: return "Storage error in cache";
> + case 7: return "Error in one or more functional units";
> + case 8: return "component failed self test";

Well, at least start them all with capital letters: "Component... " And
yes, I know this is how it is in the spec but the spec has typos and
other problems - doesn't mean we have to copy them too.

> + case 9: return "Overflow or undervalue of internal queue";
> + case 16: return "Error detected in the bus";
> + case 17: return "Virtual address not found on IO-TLB or IO-PDIR";
> + case 18: return "Improper access error";
> + case 19: return "Access to a memory address which is not mapped to any component";
> + case 20: return "Loss of Lockstep";
> + case 21: return "Response not associated with a request";
> + case 22: return "Bus parity error - must also set the A, C, or D Bits";
> + case 23: return "Detection of a PATH_ERROR ";

Trailing space here. Also what is PATH_ERROR?

That "PATH_ERROR" is nowhere else explained in that big fat UEFI spec.
2558 pages and they can't explain *that*. Geez.

> + case 25: return "Bus operation timeout";
> + case 26: return "A read was issued to data that has been poisoned";
> + default: return "reserved";
> + }
> +}
> +EXPORT_SYMBOL_GPL(cper_mem_err_status_str);
> +
> static int cper_mem_err_location(struct cper_mem_err_compact *mem, char *msg)
> {
> u32 len, n;
> @@ -334,7 +359,9 @@ static void cper_print_mem(const char *pfx, const struct cper_sec_mem_err *mem,
> return;
> }
> if (mem->validation_bits & CPER_MEM_VALID_ERROR_STATUS)
> - printk("%s""error_status: 0x%016llx\n", pfx, mem->error_status);
> + printk("%s""error_status: %s (0x%016llx)\n",

Why do you insist on having two back-to-back strings instead of one
here?

(And don't tell me it is because the other function calls here do it
too.)

FWIW, even checkpatch complains here:

WARNING: Consecutive strings are generally better as a single string
#87: FILE: drivers/firmware/efi/cper.c:362:
+ printk("%s""error_status: %s (0x%016llx)\n",

Btw, please integrate scripts/checkpatch.pl into your patch creation
workflow. Some of the warnings/errors *actually* make sense.

--
Regards/Gruss,
Boris.