From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: linux-kernel@vger.kernel.org
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@kernel.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
Jann Horn <jannh@google.com>, Kees Cook <keescook@chromium.org>,
Jessica Yu <jeyu@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ralf Baechle <ralf@linux-mips.org>,
Paul Burton <paul.burton@mips.com>,
James Hogan <jhogan@kernel.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
"David S. Miller" <davem@davemloft.net>,
linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org,
linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org,
netdev@vger.kernel.org
Subject: [PATCH 3/4] bpf: add __weak hook for allocating executable memory
Date: Sat, 17 Nov 2018 10:57:14 -0800 [thread overview]
Message-ID: <20181117185715.25198-4-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20181117185715.25198-1-ard.biesheuvel@linaro.org>
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 <ard.biesheuvel@linaro.org>
---
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;
--
2.17.1
next prev parent reply other threads:[~2018-11-17 18:57 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-17 18:57 [PATCH 0/4] bpf: permit JIT allocations to be served outside the module region Ard Biesheuvel
2018-11-17 18:57 ` [PATCH 1/4] bpf: account for freed JIT allocations in arch code Ard Biesheuvel
2018-11-19 10:37 ` Daniel Borkmann
2018-11-19 15:37 ` Ard Biesheuvel
2018-11-17 18:57 ` [PATCH 2/4] net/bpf: refactor freeing of executable allocations Ard Biesheuvel
2018-11-18 7:47 ` Y Song
2018-11-18 15:55 ` Ard Biesheuvel
2018-11-18 20:20 ` Y Song
2018-11-17 18:57 ` Ard Biesheuvel [this message]
2018-11-17 18:57 ` [PATCH 4/4] arm64/bpf: don't allocate BPF JIT programs in module memory Ard Biesheuvel
2018-11-18 7:48 ` [PATCH 0/4] bpf: permit JIT allocations to be served outside the module region Y Song
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