From dd6a403795f0c7b5c566f86f2ee6b687278d3c1c Mon Sep 17 00:00:00 2001 From: Shahab Vahedi Date: Sat, 25 May 2024 05:56:28 +0200 Subject: [PATCH] ARC, bpf: Fix issues reported by the static analyzers Also updated couple of comments along the way. One of the issues reported was indeed a bug in the code: memset(ctx, 0, sizeof(ctx)) // original line memset(ctx, 0, sizeof(*ctx)) // fixed line That was a nice catch. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202405222314.UG5F2NHn-lkp@intel.com/ Closes: https://lore.kernel.org/oe-kbuild-all/202405232036.Xqoc3b0J-lkp@intel.com/ Signed-off-by: Shahab Vahedi Link: https://lore.kernel.org/r/20240525035628.1026-1-list+bpf@vahedi.org Signed-off-by: Alexei Starovoitov --- arch/arc/net/bpf_jit.h | 2 +- arch/arc/net/bpf_jit_arcv2.c | 10 ++++++---- arch/arc/net/bpf_jit_core.c | 22 +++++++++++----------- 3 files changed, 18 insertions(+), 16 deletions(-) diff --git a/arch/arc/net/bpf_jit.h b/arch/arc/net/bpf_jit.h index ec44873c42d1..495f3023e4c1 100644 --- a/arch/arc/net/bpf_jit.h +++ b/arch/arc/net/bpf_jit.h @@ -39,7 +39,7 @@ /************** Functions that the back-end must provide **************/ /* Extension for 32-bit operations. */ -inline u8 zext(u8 *buf, u8 rd); +u8 zext(u8 *buf, u8 rd); /***** Moves *****/ u8 mov_r32(u8 *buf, u8 rd, u8 rs, u8 sign_ext); u8 mov_r32_i32(u8 *buf, u8 reg, s32 imm); diff --git a/arch/arc/net/bpf_jit_arcv2.c b/arch/arc/net/bpf_jit_arcv2.c index 31bfb6e9ce00..4458e409ca0a 100644 --- a/arch/arc/net/bpf_jit_arcv2.c +++ b/arch/arc/net/bpf_jit_arcv2.c @@ -62,7 +62,7 @@ enum { * If/when we decide to add ARCv2 instructions that do use register pairs, * the mapping, hopefully, doesn't need to be revisited. */ -const u8 bpf2arc[][2] = { +static const u8 bpf2arc[][2] = { /* Return value from in-kernel function, and exit value from eBPF */ [BPF_REG_0] = {ARC_R_8, ARC_R_9}, /* Arguments from eBPF program to in-kernel function */ @@ -1302,7 +1302,7 @@ static u8 arc_b(u8 *buf, s32 offset) /************* Packers (Deal with BPF_REGs) **************/ -inline u8 zext(u8 *buf, u8 rd) +u8 zext(u8 *buf, u8 rd) { if (rd != BPF_REG_FP) return arc_movi_r(buf, REG_HI(rd), 0); @@ -2235,6 +2235,7 @@ u8 gen_swap(u8 *buf, u8 rd, u8 size, u8 endian, bool force, bool do_zext) break; default: /* The caller must have handled this. */ + break; } } else { /* @@ -2253,6 +2254,7 @@ u8 gen_swap(u8 *buf, u8 rd, u8 size, u8 endian, bool force, bool do_zext) break; default: /* The caller must have handled this. */ + break; } } @@ -2517,7 +2519,7 @@ u8 arc_epilogue(u8 *buf, u32 usage, u16 frame_size) #define JCC64_NR_OF_JMPS 3 /* Number of jumps in jcc64 template. */ #define JCC64_INSNS_TO_END 3 /* Number of insn. inclusive the 2nd jmp to end. */ #define JCC64_SKIP_JMP 1 /* Index of the "skip" jump to "end". */ -const struct { +static const struct { /* * "jit_off" is common between all "jmp[]" and is coupled with * "cond" of each "jmp[]" instance. e.g.: @@ -2883,7 +2885,7 @@ u8 gen_jmp_64(u8 *buf, u8 rd, u8 rs, u8 cond, u32 curr_off, u32 targ_off) * The "ARC_CC_SET" becomes "CC_unequal" because of the "tst" * instruction that precedes the conditional branch. */ -const u8 arcv2_32_jmps[ARC_CC_LAST] = { +static const u8 arcv2_32_jmps[ARC_CC_LAST] = { [ARC_CC_UGT] = CC_great_u, [ARC_CC_UGE] = CC_great_eq_u, [ARC_CC_ULT] = CC_less_u, diff --git a/arch/arc/net/bpf_jit_core.c b/arch/arc/net/bpf_jit_core.c index 6f6b4ffccf2c..e3628922c24a 100644 --- a/arch/arc/net/bpf_jit_core.c +++ b/arch/arc/net/bpf_jit_core.c @@ -159,7 +159,7 @@ static void jit_dump(const struct jit_context *ctx) /* Initialise the context so there's no garbage. */ static int jit_ctx_init(struct jit_context *ctx, struct bpf_prog *prog) { - memset(ctx, 0, sizeof(ctx)); + memset(ctx, 0, sizeof(*ctx)); ctx->orig_prog = prog; @@ -167,7 +167,7 @@ static int jit_ctx_init(struct jit_context *ctx, struct bpf_prog *prog) ctx->prog = bpf_jit_blind_constants(prog); if (IS_ERR(ctx->prog)) return PTR_ERR(ctx->prog); - ctx->blinded = (ctx->prog == ctx->orig_prog ? false : true); + ctx->blinded = (ctx->prog != ctx->orig_prog); /* If the verifier doesn't zero-extend, then we have to do it. */ ctx->do_zext = !ctx->prog->aux->verifier_zext; @@ -1182,12 +1182,12 @@ static int jit_prepare(struct jit_context *ctx) } /* - * All the "handle_*()" functions have been called before by the - * "jit_prepare()". If there was an error, we would know by now. - * Therefore, no extra error checking at this point, other than - * a sanity check at the end that expects the calculated length - * (jit.len) to be equal to the length of generated instructions - * (jit.index). + * jit_compile() is the real compilation phase. jit_prepare() is + * invoked before jit_compile() as a dry-run to make sure everything + * will go OK and allocate the necessary memory. + * + * In the end, jit_compile() checks if it has produced the same number + * of instructions as jit_prepare() would. */ static int jit_compile(struct jit_context *ctx) { @@ -1407,9 +1407,9 @@ static struct bpf_prog *do_extra_pass(struct bpf_prog *prog) /* * This function may be invoked twice for the same stream of BPF - * instructions. The "extra pass" happens, when there are "call"s - * involved that their addresses are not known during the first - * invocation. + * instructions. The "extra pass" happens, when there are + * (re)locations involved that their addresses are not known + * during the first run. */ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) {