| Message ID | 20181121131733.14910-2-ard.biesheuvel@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | bpf: permit JIT allocations to be served outside the module region | expand |
Hi Ard,
I love your patch! Yet something to improve:
[auto build test ERROR on bpf-next/master]
[also build test ERROR on v4.20-rc3 next-20181122]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Ard-Biesheuvel/bpf-permit-JIT-allocations-to-be-served-outside-the-module-region/20181123-033144
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: x86_64-randconfig-x002-201846 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All error/warnings (new ones prefixed by >>):
kernel//bpf/core.c: In function 'bpf_jit_free_exec':
>> kernel//bpf/core.c:632:24: error: 'size' undeclared (first use in this function); did you mean 'ksize'?
return module_memfree(size);
^~~~
ksize
kernel//bpf/core.c:632:24: note: each undeclared identifier is reported only once for each function it appears in
>> kernel//bpf/core.c:632:9: warning: 'return' with a value, in function returning void
return module_memfree(size);
^~~~~~~~~~~~~~
kernel//bpf/core.c:630:13: note: declared here
void __weak bpf_jit_free_exec(const void *addr)
^~~~~~~~~~~~~~~~~
vim +632 kernel//bpf/core.c
629
630 void __weak bpf_jit_free_exec(const void *addr)
631 {
> 632 return module_memfree(size);
633 }
634
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
> On 22 Nov 2018, at 21:01, kbuild test robot <lkp@intel.com> wrote: > > Hi Ard, > > I love your patch! Yet something to improve: > Ugh, apologies for this. I’m sure i build tested /something/ but clearly not what i should have tested. In any case, following up on the discussion I’ll have to respin this in any case. I’ll triple check next time that what i send out was tested properly. > [auto build test ERROR on bpf-next/master] > [also build test ERROR on v4.20-rc3 next-20181122] > [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] > > url: https://github.com/0day-ci/linux/commits/Ard-Biesheuvel/bpf-permit-JIT-allocations-to-be-served-outside-the-module-region/20181123-033144 > base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master > config: x86_64-randconfig-x002-201846 (attached as .config) > compiler: gcc-7 (Debian 7.3.0-1) 7.3.0 > reproduce: > # save the attached .config to linux build tree > make ARCH=x86_64 > > All error/warnings (new ones prefixed by >>): > > kernel//bpf/core.c: In function 'bpf_jit_free_exec': >>> kernel//bpf/core.c:632:24: error: 'size' undeclared (first use in this function); did you mean 'ksize'? > return module_memfree(size); > ^~~~ > ksize > kernel//bpf/core.c:632:24: note: each undeclared identifier is reported only once for each function it appears in >>> kernel//bpf/core.c:632:9: warning: 'return' with a value, in function returning void > return module_memfree(size); > ^~~~~~~~~~~~~~ > kernel//bpf/core.c:630:13: note: declared here > void __weak bpf_jit_free_exec(const void *addr) > ^~~~~~~~~~~~~~~~~ > > vim +632 kernel//bpf/core.c > > 629 > 630 void __weak bpf_jit_free_exec(const void *addr) > 631 { >> 632 return module_memfree(size); > 633 } > 634 > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation > <.config.gz>
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 1a796e0799ec..f28d8a5eb6b8 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -609,6 +609,16 @@ 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); +} + +void __weak bpf_jit_free_exec(const void *addr) +{ + return module_memfree(size); +} + struct bpf_binary_header * bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, unsigned int alignment, @@ -626,7 +636,7 @@ 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; @@ -650,7 +660,7 @@ void bpf_jit_binary_free(struct bpf_binary_header *hdr) { u32 pages = hdr->pages; - module_memfree(hdr); + bpf_jit_free_exec(hdr); bpf_jit_uncharge_modmem(pages); }
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() and module_memfree() calls into __weak functions to allow them to be overridden in arch code. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- kernel/bpf/core.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) -- 2.17.1