From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3221627701; Tue, 25 Feb 2025 15:45:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740498319; cv=none; b=BpFxwbypgL4dDeLpd56fzAA3f1jl0465fUnmR9hA1V4zIK0f1qJ/HHKh2F03Gp74FZsOG2ftJ6oIEecId+WfhRnTW48hXYxcPkmI5EIfFT/WlnszHg1XOj2B5H6K+7WNhQj26HKCol+zh1K4abHJ057NL4lb0nBpXwHAgAIe8g0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740498319; c=relaxed/simple; bh=J5MY8MNJZjjXvPf3aaubOgBeUIi+hFPi+Z9UdY1nir8=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=nK9pU3kwkxs2liFoJgNs7SIU6m6mRJfMALg4oAbNUr+fB5plefHRRmSimoh0bJIMhZOEfMTUN/0WA3H/9KLDXn/DlonfBo+u8FiIot/ivRjV2XVjCS9OCBkOEL96ubnihLgyVeaSriJmFTNynj9MgLe4APwpAPKxYBxk/3LwEbc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B16DDC4CEDD; Tue, 25 Feb 2025 15:45:14 +0000 (UTC) Date: Tue, 25 Feb 2025 10:45:52 -0500 From: Steven Rostedt To: "Arnd Bergmann" Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, bpf , linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, "Masami Hiramatsu" , "Mark Rutland" , "Mathieu Desnoyers" , "Andrew Morton" , "Peter Zijlstra" , "Linus Torvalds" , "Masahiro Yamada" , "Nathan Chancellor" , "Nicolas Schier" , "Zheng Yejian" , "Martin Kelly" , "Christophe Leroy" , "Josh Poimboeuf" , "Heiko Carstens" , "Catalin Marinas" , "Will Deacon" , "Vasily Gorbik" , "Alexander Gordeev" Subject: Re: [PATCH v5 2/6] scripts/sorttable: Have mcount rela sort use direct values Message-ID: <20250225104552.2acc5909@gandalf.local.home> In-Reply-To: <91523154-072b-437b-bbdc-0b70e9783fd0@app.fastmail.com> References: <20250218195918.255228630@goodmis.org> <20250218200022.538888594@goodmis.org> <893cd8f1-8585-4d25-bf0f-4197bf872465@app.fastmail.com> <20250224172147.1de3fda5@gandalf.local.home> <20250224211102.33e264fc@gandalf.local.home> <91523154-072b-437b-bbdc-0b70e9783fd0@app.fastmail.com> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 25 Feb 2025 09:45:52 +0100 "Arnd Bergmann" wrote: > It fixes the build issue for me. I tried booting as well, but ran > into a BUG() when I enable ftrace. I assume this is an unrelated > issue, but you can find the output for reference in case this is > relevant. Thanks, can you try this patch instead? I'll be breaking it up if this works. This also removes the kaslr_offset() code. -- Steve diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 27c8def2139d..fdd5ffe268de 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7004,7 +7004,6 @@ static int ftrace_process_locs(struct module *mod, unsigned long count; unsigned long *p; unsigned long addr; - unsigned long kaslr; unsigned long flags = 0; /* Shut up gcc */ unsigned long pages; int ret = -ENOMEM; @@ -7056,25 +7055,37 @@ static int ftrace_process_locs(struct module *mod, ftrace_pages->next = start_pg; } - /* For zeroed locations that were shifted for core kernel */ - kaslr = !mod ? kaslr_offset() : 0; - p = start; pg = start_pg; while (p < end) { unsigned long end_offset; - addr = ftrace_call_adjust(*p++); + + addr = *p++; + /* * Some architecture linkers will pad between * the different mcount_loc sections of different * object files to satisfy alignments. * Skip any NULL pointers. */ - if (!addr || addr == kaslr) { + if (!addr) { + skipped++; + continue; + } + + /* + * If this is core kernel, make sure the address is in core + * or inittext, as weak functions get zeroed and KASLR can + * move them to something other than zero. It just will not + * move it to an area where kernel text is. + */ + if (!mod && !(is_kernel_text(addr) || is_kernel_inittext(addr))) { skipped++; continue; } + addr = ftrace_call_adjust(addr); + end_offset = (pg->index+1) * sizeof(pg->records[0]); if (end_offset > PAGE_SIZE << pg->order) { /* We should have allocated enough */ diff --git a/scripts/sorttable.c b/scripts/sorttable.c index 23c7e0e6c024..10aff2aeb868 100644 --- a/scripts/sorttable.c +++ b/scripts/sorttable.c @@ -611,13 +611,16 @@ static int add_field(uint64_t addr, uint64_t size) return 0; } +/* Used for when mcount/fentry is before the function entry */ +static int before_func; + /* Only return match if the address lies inside the function size */ static int cmp_func_addr(const void *K, const void *A) { uint64_t key = *(const uint64_t *)K; const struct func_info *a = A; - if (key < a->addr) + if (key + before_func < a->addr) return -1; return key >= a->addr + a->size; } @@ -827,9 +830,14 @@ static void *sort_mcount_loc(void *arg) pthread_exit(m_err); } - if (sort_reloc) + if (sort_reloc) { count = fill_relocs(vals, size, ehdr, emloc->start_mcount_loc); - else + /* gcc may use relocs to save the addresses, but clang does not. */ + if (!count) { + count = fill_addrs(vals, size, start_loc); + sort_reloc = 0; + } + } else count = fill_addrs(vals, size, start_loc); if (count < 0) { @@ -1248,6 +1256,8 @@ static int do_file(char const *const fname, void *addr) #ifdef MCOUNT_SORT_ENABLED sort_reloc = true; rela_type = 0x403; + /* arm64 uses patchable function entry placing before function */ + before_func = 8; #endif /* fallthrough */ case EM_386: