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| author | Jakub Kicinski <kuba@kernel.org> | 2021-02-27 00:16:29 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-02-27 00:16:31 +0300 |
| commit | 9e8e714f2d0093acf65cab330e8d1e5030eeeaa4 (patch) | |
| tree | 0e81181b7bf75661e61e3ed6cfbd65f8e7778775 /arch/x86 | |
| parent | 2c87f7a38f930ef6f6a7bdd04aeb82ce3971b54b (diff) | |
| parent | 557c223b643a35effec9654958d8edc62fd2603a (diff) | |
| download | linux-9e8e714f2d0093acf65cab330e8d1e5030eeeaa4.tar.xz | |
Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:
====================
pull-request: bpf 2021-02-26
1) Fix for bpf atomic insns with src_reg=r0, from Brendan.
2) Fix use after free due to bpf_prog_clone, from Cong.
3) Drop imprecise verifier log message, from Dmitrii.
4) Remove incorrect blank line in bpf helper description, from Hangbin.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests/bpf: No need to drop the packet when there is no geneve opt
bpf: Remove blank line in bpf helper description comment
tools/resolve_btfids: Fix build error with older host toolchains
selftests/bpf: Fix a compiler warning in global func test
bpf: Drop imprecise log message
bpf: Clear percpu pointers in bpf_prog_clone_free()
bpf: Fix a warning message in mark_ptr_not_null_reg()
bpf, x86: Fix BPF_FETCH atomic and/or/xor with r0 as src
====================
Link: https://lore.kernel.org/r/20210226193737.57004-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 79e7a0ec1da5..6926d0ca6c71 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1349,6 +1349,7 @@ st: if (is_imm8(insn->off)) insn->imm == (BPF_XOR | BPF_FETCH)) { u8 *branch_target; bool is64 = BPF_SIZE(insn->code) == BPF_DW; + u32 real_src_reg = src_reg; /* * Can't be implemented with a single x86 insn. @@ -1357,6 +1358,9 @@ st: if (is_imm8(insn->off)) /* Will need RAX as a CMPXCHG operand so save R0 */ emit_mov_reg(&prog, true, BPF_REG_AX, BPF_REG_0); + if (src_reg == BPF_REG_0) + real_src_reg = BPF_REG_AX; + branch_target = prog; /* Load old value */ emit_ldx(&prog, BPF_SIZE(insn->code), @@ -1366,9 +1370,9 @@ st: if (is_imm8(insn->off)) * put the result in the AUX_REG. */ emit_mov_reg(&prog, is64, AUX_REG, BPF_REG_0); - maybe_emit_mod(&prog, AUX_REG, src_reg, is64); + maybe_emit_mod(&prog, AUX_REG, real_src_reg, is64); EMIT2(simple_alu_opcodes[BPF_OP(insn->imm)], - add_2reg(0xC0, AUX_REG, src_reg)); + add_2reg(0xC0, AUX_REG, real_src_reg)); /* Attempt to swap in new value */ err = emit_atomic(&prog, BPF_CMPXCHG, dst_reg, AUX_REG, insn->off, @@ -1381,7 +1385,7 @@ st: if (is_imm8(insn->off)) */ EMIT2(X86_JNE, -(prog - branch_target) - 2); /* Return the pre-modification value */ - emit_mov_reg(&prog, is64, src_reg, BPF_REG_0); + emit_mov_reg(&prog, is64, real_src_reg, BPF_REG_0); /* Restore R0 after clobbering RAX */ emit_mov_reg(&prog, true, BPF_REG_0, BPF_REG_AX); break; |