Re: [REGRESSION][PATCH] Revert "pstore: migrate to crypto acomp interface"

["Guilherme G. Piccoli" <gpiccoli@igalia.com>]

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On 30/09/2022 12:51, Ard Biesheuvel wrote:
> [...]
> 
> Does this help?
> 
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index b2fd3c20e7c2..c0b609d7d04e 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -292,7 +292,7 @@ static int pstore_compress(const void *in, void *out,
>                 return ret;
>         }
> 
> -       return outlen;
> +       return creq->dlen;
>  }
> 
>  static void allocate_buf_for_compression(void)
> 

Thanks a lot Ard, this seems to be the fix! Tested with lz4/zstd/deflate
in both ramoops/efi backends, and all worked fine. It makes sense,
outlen was modified in the previous API and not in the acomp thing, so
it was a good catch =)


>> Heheh you're right! But for something like this (pstore/dmesg
>> compression broke for the most backends), I'd be glad if we could fix it
>> before the release.
> 
> Yeah better to revert - this was not a critical change anyway. But I
> think the tweak above should fix things (it works for me here)

Agreed - in fact seems it was reverted already. More than that, I found
yet another small issue in the acomp refactor, a memory leak - attached
is a patch with the fix, feel free to integrate in your acomp refactor
when re-submitting (I mean, feel free to just integrate the code, don't
need to send it as a separate patch/fix).

I'm also working some fixes in implicit conversions in pstore that
aren't great (unsigned -> int in many places), I'll send some stuff next
week.

Cheers,


Guilherme

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From cf0515dec1a339e7b644cbadaf58bfb54c9b20df Mon Sep 17 00:00:00 2001
From: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Date: Fri, 30 Sep 2022 13:45:18 -0300
Subject: [PATCH] pstore: Fix memory leak after the recent compression refactor

Fixes: e4f0a7ec586b ("pstore: migrate to crypto acomp interface")
Cc: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
---
 fs/pstore/platform.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index d244db8c879d..1765ea157d37 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -741,6 +741,7 @@ static void decompress_record(struct pstore_record *record)
 	ret = crypto_acomp_decompress(dreq);
 	if (ret) {
 		pr_err("crypto_acomp_decompress failed, ret = %d!\n", ret);
+		acomp_request_free(dreq);
 		kfree(workspace);
 		return;
 	}
-- 
2.37.3