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 E007A6FA7 for ; Sun, 17 Sep 2023 19:56:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F1C1C433C9; Sun, 17 Sep 2023 19:56:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694980607; bh=wx5P+by7N+/En+1xVhcxiRHQSohnf5cH5ke8Z6CJLdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mSMZdpXbr06bjRfH1TWDly8AYfMFxrarcwDD/NUM8iSfc+J/qSSZep1BDrZXgUpuK abRF+UBM4xgkp0YdFoKMOPvajAVIuyPIHw7DIHSAf7Qlete6U5PkCGKYfuWBcMX2FQ f6OS0O43BMsXA70bkOpfH3MHIxO4+m5WE+Fx22fo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Arnd Bergmann , Yonghong Song , Alexei Starovoitov , Sasha Levin Subject: [PATCH 6.5 242/285] bpf: fix bpf_probe_read_kernel prototype mismatch Date: Sun, 17 Sep 2023 21:14:02 +0200 Message-ID: <20230917191059.741532041@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191051.639202302@linuxfoundation.org> References: <20230917191051.639202302@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann [ Upstream commit 6a5a148aaf14747570cc634f9cdfcb0393f5617f ] bpf_probe_read_kernel() has a __weak definition in core.c and another definition with an incompatible prototype in kernel/trace/bpf_trace.c, when CONFIG_BPF_EVENTS is enabled. Since the two are incompatible, there cannot be a shared declaration in a header file, but the lack of a prototype causes a W=1 warning: kernel/bpf/core.c:1638:12: error: no previous prototype for 'bpf_probe_read_kernel' [-Werror=missing-prototypes] On 32-bit architectures, the local prototype u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) passes arguments in other registers as the one in bpf_trace.c BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, const void *, unsafe_ptr) which uses 64-bit arguments in pairs of registers. As both versions of the function are fairly simple and only really differ in one line, just move them into a header file as an inline function that does not add any overhead for the bpf_trace.c callers and actually avoids a function call for the other one. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/ac25cb0f-b804-1649-3afb-1dc6138c2716@iogearbox.net/ Signed-off-by: Arnd Bergmann Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230801111449.185301-1-arnd@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- include/linux/bpf.h | 12 ++++++++++++ kernel/bpf/core.c | 10 ++-------- kernel/trace/bpf_trace.c | 11 ----------- 3 files changed, 14 insertions(+), 19 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f58895830adae..f316affcd2e13 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2619,6 +2619,18 @@ static inline void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr) } #endif /* CONFIG_BPF_SYSCALL */ +static __always_inline int +bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) +{ + int ret = -EFAULT; + + if (IS_ENABLED(CONFIG_BPF_EVENTS)) + ret = copy_from_kernel_nofault(dst, unsafe_ptr, size); + if (unlikely(ret < 0)) + memset(dst, 0, size); + return ret; +} + void __bpf_free_used_btfs(struct bpf_prog_aux *aux, struct btf_mod_pair *used_btfs, u32 len); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index dc85240a01342..e3e45b651cd40 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1635,12 +1635,6 @@ bool bpf_opcode_in_insntable(u8 code) } #ifndef CONFIG_BPF_JIT_ALWAYS_ON -u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) -{ - memset(dst, 0, size); - return -EFAULT; -} - /** * ___bpf_prog_run - run eBPF program on a given context * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers @@ -1931,8 +1925,8 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ CONT; \ LDX_PROBE_MEM_##SIZEOP: \ - bpf_probe_read_kernel(&DST, sizeof(SIZE), \ - (const void *)(long) (SRC + insn->off)); \ + bpf_probe_read_kernel_common(&DST, sizeof(SIZE), \ + (const void *)(long) (SRC + insn->off)); \ DST = *((SIZE *)&DST); \ CONT; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 30d8db47c1e2f..abf287b2678a1 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -223,17 +223,6 @@ const struct bpf_func_proto bpf_probe_read_user_str_proto = { .arg3_type = ARG_ANYTHING, }; -static __always_inline int -bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) -{ - int ret; - - ret = copy_from_kernel_nofault(dst, unsafe_ptr, size); - if (unlikely(ret < 0)) - memset(dst, 0, size); - return ret; -} - BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, const void *, unsafe_ptr) { -- 2.40.1