From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
linux-mips@linux-mips.org, Will Deacon <will.deacon@arm.com>,
Alexei Starovoitov <ast@kernel.org>,
Paul Mackerras <paulus@samba.org>,
sparclinux@vger.kernel.org,
Daniel Borkmann <daniel@iogearbox.net>,
Catalin Marinas <catalin.marinas@arm.com>,
James Hogan <jhogan@kernel.org>,
Kees Cook <keescook@chromium.org>, Arnd Bergmann <arnd@arndb.de>,
Jann Horn <jannh@google.com>,
linux-arm-kernel@lists.infradead.org,
Eric Dumazet <eric.dumazet@gmail.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
netdev@vger.kernel.org, Ralf Baechle <ralf@linux-mips.org>,
Paul Burton <paul.burton@mips.com>, Jessica Yu <jeyu@kernel.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
linuxppc-dev@lists.ozlabs.org,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 2/4] net/bpf: refactor freeing of executable allocations
Date: Sat, 17 Nov 2018 10:57:13 -0800 [thread overview]
Message-ID: <20181117185715.25198-3-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20181117185715.25198-1-ard.biesheuvel@linaro.org>
All arch overrides of the __weak bpf_jit_free() amount to the same
thing: the allocated memory was never mapped read-only, and so
it does not have to be remapped to read-write before being freed.
So in preparation of permitting arches to serve allocations for BPF
JIT programs from other regions than the module region, refactor
the existing bpf_jit_free() implementations to use the shared code
where possible, and only specialize the remap and free operations.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
arch/mips/net/bpf_jit.c | 7 ++-----
arch/powerpc/net/bpf_jit_comp.c | 7 ++-----
arch/powerpc/net/bpf_jit_comp64.c | 9 +++------
arch/sparc/net/bpf_jit_comp_32.c | 7 ++-----
kernel/bpf/core.c | 15 +++++----------
5 files changed, 14 insertions(+), 31 deletions(-)
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 1b69897274a1..5696bd7dccc7 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -1261,10 +1261,7 @@ void bpf_jit_compile(struct bpf_prog *fp)
kfree(ctx.offsets);
}
-void bpf_jit_free(struct bpf_prog *fp)
+void bpf_jit_binary_free(struct bpf_binary_header *hdr)
{
- if (fp->jited)
- bpf_jit_binary_free(bpf_jit_binary_hdr(fp));
-
- bpf_prog_unlock_free(fp);
+ module_memfree(hdr);
}
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index a1ea1ea6b40d..5b5ce4a1b44b 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -680,10 +680,7 @@ void bpf_jit_compile(struct bpf_prog *fp)
return;
}
-void bpf_jit_free(struct bpf_prog *fp)
+void bpf_jit_binary_free(struct bpf_binary_header *hdr)
{
- if (fp->jited)
- bpf_jit_binary_free(bpf_jit_binary_hdr(fp));
-
- bpf_prog_unlock_free(fp);
+ module_memfree(hdr);
}
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 84c8f013a6c6..f64f1294bd62 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -1021,11 +1021,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
return fp;
}
-/* Overriding bpf_jit_free() as we don't set images read-only. */
-void bpf_jit_free(struct bpf_prog *fp)
+/* Overriding bpf_jit_binary_free() as we don't set images read-only. */
+void bpf_jit_binary_free(struct bpf_binary_header *hdr)
{
- if (fp->jited)
- bpf_jit_binary_free(bpf_jit_binary_hdr(fp));
-
- bpf_prog_unlock_free(fp);
+ module_memfree(hdr);
}
diff --git a/arch/sparc/net/bpf_jit_comp_32.c b/arch/sparc/net/bpf_jit_comp_32.c
index 01bda6bc9e7f..589950d152cc 100644
--- a/arch/sparc/net/bpf_jit_comp_32.c
+++ b/arch/sparc/net/bpf_jit_comp_32.c
@@ -756,10 +756,7 @@ cond_branch: f_offset = addrs[i + filter[i].jf];
return;
}
-void bpf_jit_free(struct bpf_prog *fp)
+void bpf_jit_binary_free(struct bpf_binary_header *hdr)
{
- if (fp->jited)
- bpf_jit_binary_free(bpf_jit_binary_hdr(fp));
-
- bpf_prog_unlock_free(fp);
+ module_memfree(hdr);
}
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 1a796e0799ec..29f766dac203 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -646,25 +646,20 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
return hdr;
}
-void bpf_jit_binary_free(struct bpf_binary_header *hdr)
+void __weak bpf_jit_binary_free(struct bpf_binary_header *hdr)
{
- u32 pages = hdr->pages;
-
+ bpf_jit_binary_unlock_ro(hdr);
module_memfree(hdr);
- bpf_jit_uncharge_modmem(pages);
}
-/* This symbol is only overridden by archs that have different
- * requirements than the usual eBPF JITs, f.e. when they only
- * implement cBPF JIT, do not set images read-only, etc.
- */
-void __weak bpf_jit_free(struct bpf_prog *fp)
+void bpf_jit_free(struct bpf_prog *fp)
{
if (fp->jited) {
struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
+ u32 pages = hdr->pages;
- bpf_jit_binary_unlock_ro(hdr);
bpf_jit_binary_free(hdr);
+ bpf_jit_uncharge_modmem(pages);
WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
}
--
2.17.1
next prev parent reply other threads:[~2018-11-17 19:08 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 ` Ard Biesheuvel [this message]
2018-11-18 7:47 ` [PATCH 2/4] net/bpf: refactor freeing of executable allocations Y Song
2018-11-18 15:55 ` Ard Biesheuvel
2018-11-18 20:20 ` Y Song
2018-11-17 18:57 ` [PATCH 3/4] bpf: add __weak hook for allocating executable memory Ard Biesheuvel
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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