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Sat, 17 Nov 2018 10:57:23 -0800 (PST) Received: from mba13.psav.com ([64.114.255.114]) by smtp.gmail.com with ESMTPSA id u76-v6sm49550745pfa.176.2018.11.17.10.57.22 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 17 Nov 2018 10:57:22 -0800 (PST) From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Subject: [PATCH 3/4] bpf: add __weak hook for allocating executable memory Date: Sat, 17 Nov 2018 10:57:14 -0800 Message-Id: <20181117185715.25198-4-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181117185715.25198-1-ard.biesheuvel@linaro.org> References: <20181117185715.25198-1-ard.biesheuvel@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181117_105730_779844_F37AF89D X-CRM114-Status: GOOD ( 15.12 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-mips@linux-mips.org, Benjamin Herrenschmidt , Will Deacon , Alexei Starovoitov , Paul Mackerras , sparclinux@vger.kernel.org, Daniel Borkmann , Michael Ellerman , Catalin Marinas , James Hogan , Kees Cook , Arnd Bergmann , Jann Horn , linux-arm-kernel@lists.infradead.org, Eric Dumazet , Ard Biesheuvel , netdev@vger.kernel.org, Ralf Baechle , Paul Burton , Jessica Yu , Rick Edgecombe , linuxppc-dev@lists.ozlabs.org, "David S. Miller" MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP By default, BPF uses module_alloc() to allocate executable memory, but this is not necessary on all arches and potentially undesirable on some of them. So break out the module_alloc() call into a __weak function to allow it to be overridden in arch code. Signed-off-by: Ard Biesheuvel --- kernel/bpf/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 29f766dac203..156d6b96ac6c 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -609,6 +609,11 @@ static void bpf_jit_uncharge_modmem(u32 pages) atomic_long_sub(pages, &bpf_jit_current); } +void *__weak bpf_jit_alloc_exec(unsigned long size) +{ + return module_alloc(size); +} + struct bpf_binary_header * bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, unsigned int alignment, @@ -626,7 +631,7 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, if (bpf_jit_charge_modmem(pages)) return NULL; - hdr = module_alloc(size); + hdr = bpf_jit_alloc_exec(size); if (!hdr) { bpf_jit_uncharge_modmem(pages); return NULL;