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From: Jakub Sitnicki <jakub@cloudflare.com>
To: Jiri Olsa <jolsa@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
	 Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	 Masami Hiramatsu <mhiramat@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>,
	 bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCHv4 09/13] selftests/bpf: Change uprobe syscall tests to use nop10
Date: Wed, 27 May 2026 12:30:47 +0200	[thread overview]
Message-ID: <8733zd6t60.fsf@cloudflare.com> (raw)
In-Reply-To: <20260526205840.173790-10-jolsa@kernel.org> (Jiri Olsa's message of "Tue, 26 May 2026 22:58:36 +0200")

On Tue, May 26, 2026 at 10:58 PM +02, Jiri Olsa wrote:
> Optimized uprobes are now on top of 10-bytes nop instructions,
> reflect that in existing tests.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---

[...]

> @@ -430,9 +432,11 @@ static void *check_attach(struct uprobe_syscall_executed *skel, trigger_t trigge
>  
>  static void check_detach(void *addr, void *tramp)
>  {
> +	static const char nop10_prefix[] = { 0x66, 0x2e, 0x0f, 0x1f, 0x84 };
> +
>  	/* [uprobes_trampoline] stays after detach */
>  	ASSERT_OK(find_uprobes_trampoline(tramp), "uprobes_trampoline");
> -	ASSERT_OK(memcmp(addr, nop5, 5), "nop5");
> +	ASSERT_OK(memcmp(addr, nop10_prefix, 5), "nop10_prefix");
>  }
>  
>  static void check(struct uprobe_syscall_executed *skel, struct bpf_link *link,

Nit: You could just do `memcmp(addr, nop10, 5)` to match the prefix.

Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>

  parent reply	other threads:[~2026-05-27 10:30 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-26 20:58 [PATCHv4 00/13] uprobes/x86: Fix red zone issue for optimized uprobes Jiri Olsa
2026-05-26 20:58 ` [PATCHv4 01/13] uprobes/x86: Use proper mm_struct in __in_uprobe_trampoline Jiri Olsa
2026-05-26 20:58 ` [PATCHv4 02/13] uprobes/x86: Remove struct uprobe_trampoline object Jiri Olsa
2026-05-26 21:46   ` bot+bpf-ci
2026-05-27  9:58     ` Jiri Olsa
2026-05-26 20:58 ` [PATCHv4 03/13] uprobes/x86: Allow to copy uprobe trampolines on fork Jiri Olsa
2026-05-26 21:46   ` bot+bpf-ci
2026-05-27  9:58     ` Jiri Olsa
2026-05-26 20:58 ` [PATCHv4 04/13] uprobes/x86: Unmap trampoline vma object in case it's unused Jiri Olsa
2026-05-26 21:46   ` bot+bpf-ci
2026-05-27  9:57     ` Jiri Olsa
2026-05-26 20:58 ` [PATCHv4 05/13] uprobes/x86: Move optimized uprobe from nop5 to nop10 Jiri Olsa
2026-05-26 20:58 ` [PATCHv4 06/13] libbpf: Change has_nop_combo to work on top of nop10 Jiri Olsa
2026-05-26 21:46   ` bot+bpf-ci
2026-05-27  9:57     ` Jiri Olsa
2026-05-26 20:58 ` [PATCHv4 07/13] libbpf: Detect uprobe syscall with new error Jiri Olsa
2026-05-26 21:46   ` bot+bpf-ci
2026-05-26 20:58 ` [PATCHv4 08/13] selftests/bpf: Emit nop,nop10 instructions combo for x86_64 arch Jiri Olsa
2026-05-26 21:46   ` bot+bpf-ci
2026-05-26 20:58 ` [PATCHv4 09/13] selftests/bpf: Change uprobe syscall tests to use nop10 Jiri Olsa
2026-05-26 21:46   ` bot+bpf-ci
2026-05-27  9:58     ` Jiri Olsa
2026-05-27 10:30   ` Jakub Sitnicki [this message]
2026-05-26 20:58 ` [PATCHv4 10/13] selftests/bpf: Change uprobe/usdt trigger bench code " Jiri Olsa
2026-05-27 10:46   ` Jakub Sitnicki
2026-05-26 20:58 ` [PATCHv4 11/13] selftests/bpf: Add reattach tests for uprobe syscall Jiri Olsa
2026-05-27 11:32   ` Jakub Sitnicki
2026-05-26 20:58 ` [PATCHv4 12/13] selftests/bpf: Add tests for uprobe nop10 red zone clobbering Jiri Olsa
2026-05-26 21:46   ` bot+bpf-ci
2026-05-27 10:26     ` Jiri Olsa
2026-05-26 20:58 ` [PATCHv4 13/13] selftests/bpf: Add tests for forked/cloned optimized uprobes Jiri Olsa

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