Re: [PATCH] perf/genelf: Switch deprecated openssl MD5_* functions to new EVP API

From: Arnaldo Carvalho de Melo
Date: Thu Aug 25 2022 - 16:17:26 EST


Em Fri, Aug 26, 2022 at 01:00:58AM +0800, Zixuan Tan escreveu:
> Switch to the flavored EVP API like in test-libcrypto.c, and remove the
> bad gcc #pragma.
>
> Inspired-By: 5b245985a6de ("tools build: Switch to new openssl API for
> test-libcrypto")

How did you test the end result? Can you please describe step by step?

Also please consider adding a 'perf test' entry to make sure this
doesn't regress.

Thanks,

- Arnaldo

> Signed-off-by: Zixuan Tan <tanzixuan.me@xxxxxxxxx>
> ---
> tools/perf/util/genelf.c | 20 +++++++++++---------
> 1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/tools/perf/util/genelf.c b/tools/perf/util/genelf.c
> index 953338b9e887..ed28a0dbcb7f 100644
> --- a/tools/perf/util/genelf.c
> +++ b/tools/perf/util/genelf.c
> @@ -30,10 +30,6 @@
>
> #define BUILD_ID_URANDOM /* different uuid for each run */
>
> -// FIXME, remove this and fix the deprecation warnings before its removed and
> -// We'll break for good here...
> -#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
> -
> #ifdef HAVE_LIBCRYPTO_SUPPORT
>
> #define BUILD_ID_MD5
> @@ -45,6 +41,7 @@
> #endif
>
> #ifdef BUILD_ID_MD5
> +#include <openssl/evp.h>
> #include <openssl/md5.h>
> #endif
> #endif
> @@ -142,15 +139,20 @@ gen_build_id(struct buildid_note *note,
> static void
> gen_build_id(struct buildid_note *note, unsigned long load_addr,
> const void *code, size_t csize)
> {
> - MD5_CTX context;
> + EVP_MD_CTX *mdctx;
>
> if (sizeof(note->build_id) < 16)
> errx(1, "build_id too small for MD5");
>
> - MD5_Init(&context);
> - MD5_Update(&context, &load_addr, sizeof(load_addr));
> - MD5_Update(&context, code, csize);
> - MD5_Final((unsigned char *)note->build_id, &context);
> + mdctx = EVP_MD_CTX_new();
> + if (!mdctx)
> + errx(2, "failed to create EVP_MD_CTX");
> +
> + EVP_DigestInit_ex(mdctx, EVP_md5(), NULL);
> + EVP_DigestUpdate(mdctx, &load_addr, sizeof(load_addr));
> + EVP_DigestUpdate(mdctx, code, csize);
> + EVP_DigestFinal_ex(mdctx, (unsigned char *)note->build_id, NULL);
> + EVP_MD_CTX_free(mdctx);
> }
> #endif
>
> --
> 2.34.1

--

- Arnaldo