diff options
Diffstat (limited to 'arch/mips/net/bpf_jit_comp32.c')
| -rw-r--r-- | arch/mips/net/bpf_jit_comp32.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/mips/net/bpf_jit_comp32.c b/arch/mips/net/bpf_jit_comp32.c index 83c975d5cca2..40a878b672f5 100644 --- a/arch/mips/net/bpf_jit_comp32.c +++ b/arch/mips/net/bpf_jit_comp32.c @@ -95,7 +95,7 @@ /* * Mapping of 64-bit eBPF registers to 32-bit native MIPS registers. * - * 1) Native register pairs are ordered according to CPU endiannes, following + * 1) Native register pairs are ordered according to CPU endianness, following * the MIPS convention for passing 64-bit arguments and return values. * 2) The eBPF return value, arguments and callee-saved registers are mapped * to their native MIPS equivalents. @@ -1377,11 +1377,19 @@ void build_prologue(struct jit_context *ctx) int stack, saved, locals, reserved; /* + * In the unlikely event that the TCC limit is raised to more + * than 16 bits, it is clamped to the maximum value allowed for + * the generated code (0xffff). It is better fail to compile + * instead of degrading gracefully. + */ + BUILD_BUG_ON(MAX_TAIL_CALL_CNT > 0xffff); + + /* * The first two instructions initialize TCC in the reserved (for us) * 16-byte area in the parent's stack frame. On a tail call, the * calling function jumps into the prologue after these instructions. */ - emit(ctx, ori, MIPS_R_T9, MIPS_R_ZERO, min(MAX_TAIL_CALL_CNT, 0xffff)); + emit(ctx, ori, MIPS_R_T9, MIPS_R_ZERO, MAX_TAIL_CALL_CNT); emit(ctx, sw, MIPS_R_T9, 0, MIPS_R_SP); /* |