| From 916cafdc95843fb9af5fd5f83ca499d75473d107 Mon Sep 17 00:00:00 2001 |
| From: Mathias Svensson <idolf@google.com> |
| Date: Fri, 6 Jan 2017 13:32:39 -0800 |
| Subject: samples/seccomp: fix 64-bit comparison macros |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Mathias Svensson <idolf@google.com> |
| |
| commit 916cafdc95843fb9af5fd5f83ca499d75473d107 upstream. |
| |
| There were some bugs in the JNE64 and JLT64 comparision macros. This fixes |
| them, improves comments, and cleans up the file while we are at it. |
| |
| Reported-by: Stephen Rรถttger <sroettger@google.com> |
| Signed-off-by: Mathias Svensson <idolf@google.com> |
| Signed-off-by: Kees Cook <keescook@chromium.org> |
| Signed-off-by: James Morris <james.l.morris@oracle.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| samples/seccomp/bpf-helper.h | 125 ++++++++++++++++++++++++------------------- |
| 1 file changed, 72 insertions(+), 53 deletions(-) |
| |
| --- a/samples/seccomp/bpf-helper.h |
| +++ b/samples/seccomp/bpf-helper.h |
| @@ -138,7 +138,7 @@ union arg64 { |
| #define ARG_32(idx) \ |
| BPF_STMT(BPF_LD+BPF_W+BPF_ABS, LO_ARG(idx)) |
| |
| -/* Loads hi into A and lo in X */ |
| +/* Loads lo into M[0] and hi into M[1] and A */ |
| #define ARG_64(idx) \ |
| BPF_STMT(BPF_LD+BPF_W+BPF_ABS, LO_ARG(idx)), \ |
| BPF_STMT(BPF_ST, 0), /* lo -> M[0] */ \ |
| @@ -153,88 +153,107 @@ union arg64 { |
| BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (value), 1, 0), \ |
| jt |
| |
| -/* Checks the lo, then swaps to check the hi. A=lo,X=hi */ |
| +#define JA32(value, jt) \ |
| + BPF_JUMP(BPF_JMP+BPF_JSET+BPF_K, (value), 0, 1), \ |
| + jt |
| + |
| +#define JGE32(value, jt) \ |
| + BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (value), 0, 1), \ |
| + jt |
| + |
| +#define JGT32(value, jt) \ |
| + BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (value), 0, 1), \ |
| + jt |
| + |
| +#define JLE32(value, jt) \ |
| + BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (value), 1, 0), \ |
| + jt |
| + |
| +#define JLT32(value, jt) \ |
| + BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (value), 1, 0), \ |
| + jt |
| + |
| +/* |
| + * All the JXX64 checks assume lo is saved in M[0] and hi is saved in both |
| + * A and M[1]. This invariant is kept by restoring A if necessary. |
| + */ |
| #define JEQ64(lo, hi, jt) \ |
| + /* if (hi != arg.hi) goto NOMATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 0, 5), \ |
| BPF_STMT(BPF_LD+BPF_MEM, 0), /* swap in lo */ \ |
| + /* if (lo != arg.lo) goto NOMATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (lo), 0, 2), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1), /* passed: swap hi back in */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1), \ |
| jt, \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1) /* failed: swap hi back in */ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1) |
| |
| #define JNE64(lo, hi, jt) \ |
| - BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 5, 0), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 0), /* swap in lo */ \ |
| + /* if (hi != arg.hi) goto MATCH; */ \ |
| + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 0, 3), \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 0), \ |
| + /* if (lo != arg.lo) goto MATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (lo), 2, 0), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1), /* passed: swap hi back in */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1), \ |
| jt, \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1) /* failed: swap hi back in */ |
| - |
| -#define JA32(value, jt) \ |
| - BPF_JUMP(BPF_JMP+BPF_JSET+BPF_K, (value), 0, 1), \ |
| - jt |
| + BPF_STMT(BPF_LD+BPF_MEM, 1) |
| |
| #define JA64(lo, hi, jt) \ |
| + /* if (hi & arg.hi) goto MATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JSET+BPF_K, (hi), 3, 0), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 0), /* swap in lo */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 0), \ |
| + /* if (lo & arg.lo) goto MATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JSET+BPF_K, (lo), 0, 2), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1), /* passed: swap hi back in */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1), \ |
| jt, \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1) /* failed: swap hi back in */ |
| - |
| -#define JGE32(value, jt) \ |
| - BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (value), 0, 1), \ |
| - jt |
| + BPF_STMT(BPF_LD+BPF_MEM, 1) |
| |
| -#define JLT32(value, jt) \ |
| - BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (value), 1, 0), \ |
| - jt |
| - |
| -/* Shortcut checking if hi > arg.hi. */ |
| #define JGE64(lo, hi, jt) \ |
| + /* if (hi > arg.hi) goto MATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (hi), 4, 0), \ |
| + /* if (hi != arg.hi) goto NOMATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 0, 5), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 0), /* swap in lo */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 0), \ |
| + /* if (lo >= arg.lo) goto MATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (lo), 0, 2), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1), /* passed: swap hi back in */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1), \ |
| jt, \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1) /* failed: swap hi back in */ |
| - |
| -#define JLT64(lo, hi, jt) \ |
| - BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (hi), 0, 4), \ |
| - BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 0, 5), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 0), /* swap in lo */ \ |
| - BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (lo), 2, 0), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1), /* passed: swap hi back in */ \ |
| - jt, \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1) /* failed: swap hi back in */ |
| - |
| -#define JGT32(value, jt) \ |
| - BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (value), 0, 1), \ |
| - jt |
| - |
| -#define JLE32(value, jt) \ |
| - BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (value), 1, 0), \ |
| - jt |
| + BPF_STMT(BPF_LD+BPF_MEM, 1) |
| |
| -/* Check hi > args.hi first, then do the GE checking */ |
| #define JGT64(lo, hi, jt) \ |
| + /* if (hi > arg.hi) goto MATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (hi), 4, 0), \ |
| + /* if (hi != arg.hi) goto NOMATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 0, 5), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 0), /* swap in lo */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 0), \ |
| + /* if (lo > arg.lo) goto MATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (lo), 0, 2), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1), /* passed: swap hi back in */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1), \ |
| jt, \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1) /* failed: swap hi back in */ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1) |
| |
| #define JLE64(lo, hi, jt) \ |
| - BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (hi), 6, 0), \ |
| - BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 0, 3), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 0), /* swap in lo */ \ |
| + /* if (hi < arg.hi) goto MATCH; */ \ |
| + BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (hi), 0, 4), \ |
| + /* if (hi != arg.hi) goto NOMATCH; */ \ |
| + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 0, 5), \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 0), \ |
| + /* if (lo <= arg.lo) goto MATCH; */ \ |
| BPF_JUMP(BPF_JMP+BPF_JGT+BPF_K, (lo), 2, 0), \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1), /* passed: swap hi back in */ \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1), \ |
| + jt, \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1) |
| + |
| +#define JLT64(lo, hi, jt) \ |
| + /* if (hi < arg.hi) goto MATCH; */ \ |
| + BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (hi), 0, 4), \ |
| + /* if (hi != arg.hi) goto NOMATCH; */ \ |
| + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, (hi), 0, 5), \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 0), \ |
| + /* if (lo < arg.lo) goto MATCH; */ \ |
| + BPF_JUMP(BPF_JMP+BPF_JGE+BPF_K, (lo), 2, 0), \ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1), \ |
| jt, \ |
| - BPF_STMT(BPF_LD+BPF_MEM, 1) /* failed: swap hi back in */ |
| + BPF_STMT(BPF_LD+BPF_MEM, 1) |
| |
| #define LOAD_SYSCALL_NR \ |
| BPF_STMT(BPF_LD+BPF_W+BPF_ABS, \ |
