Re: [PATCH 1/1] eal: enable xz read support and ignore warning

[David Marchand <david.marchand@redhat.com>]

Hello,

Thank you for the patch.

On Fri, Sep 22, 2023 at 6:54 PM Srikanth Yalavarthi
<syalavarthi@marvell.com> wrote:
>
> archive_read_support_filter_xz returns a warning when
> compression is not fully supported and is supported
> through external program. This warning can be ignored
> when reading the files through firmware open as only
> decompression is required.

- I don't understand the last sentence, it seems to state something
about *only* needing decompression support but well,
archive_read_support_filter_xz (like archive_read_support_filter_*
other helpers) *is about* decompressing a file.


- I can't reproduce this ARCHIVE_WARN thing, not sure which libarchive
you use, or which knob/build option triggered this behavior you
observe.
So I need you to to double check how this change affects the code.

Please pass a xz-compressed mldev fw .bin file and confirm it still works.


>
> Fixes: 40edb9c0d36b ("eal: handle compressed firmware")
> Cc: stable@dpdk.org
>
> Signed-off-by: Srikanth Yalavarthi <syalavarthi@marvell.com>
> ---
>  lib/eal/unix/eal_firmware.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/lib/eal/unix/eal_firmware.c b/lib/eal/unix/eal_firmware.c
> index d1616b0bd9..05c06c222a 100644
> --- a/lib/eal/unix/eal_firmware.c
> +++ b/lib/eal/unix/eal_firmware.c
> @@ -25,12 +25,19 @@ static int
>  firmware_open(struct firmware_read_ctx *ctx, const char *name, size_t blocksize)
>  {
>         struct archive_entry *e;
> +       int err;
>
>         ctx->a = archive_read_new();
>         if (ctx->a == NULL)
>                 return -1;
> +
> +       err = archive_read_support_filter_xz(ctx->a);
> +       if (err != ARCHIVE_OK && err != ARCHIVE_WARN) {
> +               ctx->a = NULL;
> +               return -1;
> +       }

- This patch leaks ctx->a content on error.

Plus I prefer we keep the original order of the code because it
matches what libarchive does: first look for an archive format, then
next look for compression matters.

The simpler is to add an error label like I did in the debug patch.
Something like:

diff --git a/lib/eal/unix/eal_firmware.c b/lib/eal/unix/eal_firmware.c
index d1616b0bd9..269688d550 100644
--- a/lib/eal/unix/eal_firmware.c
+++ b/lib/eal/unix/eal_firmware.c
@@ -25,19 +25,27 @@ static int
 firmware_open(struct firmware_read_ctx *ctx, const char *name, size_t
blocksize)
 {
        struct archive_entry *e;
+       int err;

        ctx->a = archive_read_new();
        if (ctx->a == NULL)
                return -1;
-       if (archive_read_support_format_raw(ctx->a) != ARCHIVE_OK ||
-                       archive_read_support_filter_xz(ctx->a) != ARCHIVE_OK ||
-                       archive_read_open_filename(ctx->a, name,
blocksize) != ARCHIVE_OK ||
-                       archive_read_next_header(ctx->a, &e) != ARCHIVE_OK) {
-               archive_read_free(ctx->a);
-               ctx->a = NULL;
-               return -1;
-       }
+       if (archive_read_support_format_raw(ctx->a) != ARCHIVE_OK)
+               goto error;
+       err = archive_read_support_filter_xz(ctx->a);
+       if (err != ARCHIVE_OK && err != ARCHIVE_WARN)
+               goto error;
+       if (archive_read_open_filename(ctx->a, name, blocksize) != ARCHIVE_OK)
+               goto error;
+       if (archive_read_next_header(ctx->a, &e))
+               goto error;
+
        return 0;
+
+error:
+       archive_read_free(ctx->a);
+       ctx->a = NULL;
+       return -1;
 }

 static ssize_t


-- 
David Marchand