Skip to content
Snippets Groups Projects
Select Git revision
  • d1a2930d8a992fb6ac2529449f81a0056e1b98d1
  • vme-testing default
  • ci-test
  • master
  • remoteproc
  • am625-sk-ov5640
  • pcal6534-upstreaming
  • lps22df-upstreaming
  • msc-upstreaming
  • imx8mp
  • iio/noa1305
  • vme-next
  • vme-next-4.14-rc4
  • v4.14-rc4
  • v4.14-rc3
  • v4.14-rc2
  • v4.14-rc1
  • v4.13
  • vme-next-4.13-rc7
  • v4.13-rc7
  • v4.13-rc6
  • v4.13-rc5
  • v4.13-rc4
  • v4.13-rc3
  • v4.13-rc2
  • v4.13-rc1
  • v4.12
  • v4.12-rc7
  • v4.12-rc6
  • v4.12-rc5
  • v4.12-rc4
  • v4.12-rc3
32 results

ebpf_jit.c

Blame
    • Paul Burton's avatar
      d1a2930d
      MIPS: eBPF: Fix icache flush end address · d1a2930d
      Paul Burton authored
      
      The MIPS eBPF JIT calls flush_icache_range() in order to ensure the
      icache observes the code that we just wrote. Unfortunately it gets the
      end address calculation wrong due to some bad pointer arithmetic.
      
      The struct jit_ctx target field is of type pointer to u32, and as such
      adding one to it will increment the address being pointed to by 4 bytes.
      Therefore in order to find the address of the end of the code we simply
      need to add the number of 4 byte instructions emitted, but we mistakenly
      add the number of instructions multiplied by 4. This results in the call
      to flush_icache_range() operating on a memory region 4x larger than
      intended, which is always wasteful and can cause crashes if we overrun
      into an unmapped page.
      
      Fix this by correcting the pointer arithmetic to remove the bogus
      multiplication, and use braces to remove the need for a set of brackets
      whilst also making it obvious that the target field is a pointer.
      
      Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
      Fixes: b6bd53f9 ("MIPS: Add missing file for eBPF JIT.")
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: Martin KaFai Lau <kafai@fb.com>
      Cc: Song Liu <songliubraving@fb.com>
      Cc: Yonghong Song <yhs@fb.com>
      Cc: netdev@vger.kernel.org
      Cc: bpf@vger.kernel.org
      Cc: linux-mips@vger.kernel.org
      Cc: stable@vger.kernel.org # v4.13+
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      d1a2930d
      History
      MIPS: eBPF: Fix icache flush end address
      Paul Burton authored
      
      The MIPS eBPF JIT calls flush_icache_range() in order to ensure the
      icache observes the code that we just wrote. Unfortunately it gets the
      end address calculation wrong due to some bad pointer arithmetic.
      
      The struct jit_ctx target field is of type pointer to u32, and as such
      adding one to it will increment the address being pointed to by 4 bytes.
      Therefore in order to find the address of the end of the code we simply
      need to add the number of 4 byte instructions emitted, but we mistakenly
      add the number of instructions multiplied by 4. This results in the call
      to flush_icache_range() operating on a memory region 4x larger than
      intended, which is always wasteful and can cause crashes if we overrun
      into an unmapped page.
      
      Fix this by correcting the pointer arithmetic to remove the bogus
      multiplication, and use braces to remove the need for a set of brackets
      whilst also making it obvious that the target field is a pointer.
      
      Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
      Fixes: b6bd53f9 ("MIPS: Add missing file for eBPF JIT.")
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: Martin KaFai Lau <kafai@fb.com>
      Cc: Song Liu <songliubraving@fb.com>
      Cc: Yonghong Song <yhs@fb.com>
      Cc: netdev@vger.kernel.org
      Cc: bpf@vger.kernel.org
      Cc: linux-mips@vger.kernel.org
      Cc: stable@vger.kernel.org # v4.13+
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
    hugetlb.c 19.04 KiB