diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-09-18 11:55:43 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-09-18 11:55:43 -0700 |
commit | 69828c475d15290553cb5512108424746baf6225 (patch) | |
tree | a2f1251918b9bb39836dd81f23342466990d7501 /arch | |
parent | 5a55d36f715b01a00c1ad7127a73044c6f1c9668 (diff) | |
parent | 75df529bec9110dad43ab30e2d9490242529e8b8 (diff) |
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- Allow CPUs affected by erratum 1418040 to come online late
(previously we only fixed the other case - CPUs not affected by the
erratum coming up late).
- Fix branch offset in BPF JIT.
- Defer the stolen time initialisation to the CPU online time from the
CPU starting time to avoid a (sleep-able) memory allocation in an
atomic context.
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: paravirt: Initialize steal time when cpu is online
arm64: bpf: Fix branch offset in JIT
arm64: Allow CPUs unffected by ARM erratum 1418040 to come in late
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 8 | ||||
-rw-r--r-- | arch/arm64/kernel/paravirt.c | 26 | ||||
-rw-r--r-- | arch/arm64/net/bpf_jit_comp.c | 43 |
3 files changed, 52 insertions, 25 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index c332d49780dc..560ba69e13c1 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -910,8 +910,12 @@ const struct arm64_cpu_capabilities arm64_errata[] = { .desc = "ARM erratum 1418040", .capability = ARM64_WORKAROUND_1418040, ERRATA_MIDR_RANGE_LIST(erratum_1418040_list), - .type = (ARM64_CPUCAP_SCOPE_LOCAL_CPU | - ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU), + /* + * We need to allow affected CPUs to come in late, but + * also need the non-affected CPUs to be able to come + * in at any point in time. Wonderful. + */ + .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, }, #endif #ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_AT diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c index 295d66490584..c07d7a034941 100644 --- a/arch/arm64/kernel/paravirt.c +++ b/arch/arm64/kernel/paravirt.c @@ -50,16 +50,19 @@ static u64 pv_steal_clock(int cpu) struct pv_time_stolen_time_region *reg; reg = per_cpu_ptr(&stolen_time_region, cpu); - if (!reg->kaddr) { - pr_warn_once("stolen time enabled but not configured for cpu %d\n", - cpu); + + /* + * paravirt_steal_clock() may be called before the CPU + * online notification callback runs. Until the callback + * has run we just return zero. + */ + if (!reg->kaddr) return 0; - } return le64_to_cpu(READ_ONCE(reg->kaddr->stolen_time)); } -static int stolen_time_dying_cpu(unsigned int cpu) +static int stolen_time_cpu_down_prepare(unsigned int cpu) { struct pv_time_stolen_time_region *reg; @@ -73,7 +76,7 @@ static int stolen_time_dying_cpu(unsigned int cpu) return 0; } -static int init_stolen_time_cpu(unsigned int cpu) +static int stolen_time_cpu_online(unsigned int cpu) { struct pv_time_stolen_time_region *reg; struct arm_smccc_res res; @@ -103,19 +106,20 @@ static int init_stolen_time_cpu(unsigned int cpu) return 0; } -static int pv_time_init_stolen_time(void) +static int __init pv_time_init_stolen_time(void) { int ret; - ret = cpuhp_setup_state(CPUHP_AP_ARM_KVMPV_STARTING, - "hypervisor/arm/pvtime:starting", - init_stolen_time_cpu, stolen_time_dying_cpu); + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "hypervisor/arm/pvtime:online", + stolen_time_cpu_online, + stolen_time_cpu_down_prepare); if (ret < 0) return ret; return 0; } -static bool has_pv_steal_clock(void) +static bool __init has_pv_steal_clock(void) { struct arm_smccc_res res; diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index f8912e45be7a..ef9f1d5e989d 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -143,14 +143,17 @@ static inline void emit_addr_mov_i64(const int reg, const u64 val, } } -static inline int bpf2a64_offset(int bpf_to, int bpf_from, +static inline int bpf2a64_offset(int bpf_insn, int off, const struct jit_ctx *ctx) { - int to = ctx->offset[bpf_to]; - /* -1 to account for the Branch instruction */ - int from = ctx->offset[bpf_from] - 1; - - return to - from; + /* BPF JMP offset is relative to the next instruction */ + bpf_insn++; + /* + * Whereas arm64 branch instructions encode the offset + * from the branch itself, so we must subtract 1 from the + * instruction offset. + */ + return ctx->offset[bpf_insn + off] - (ctx->offset[bpf_insn] - 1); } static void jit_fill_hole(void *area, unsigned int size) @@ -642,7 +645,7 @@ emit_bswap_uxt: /* JUMP off */ case BPF_JMP | BPF_JA: - jmp_offset = bpf2a64_offset(i + off, i, ctx); + jmp_offset = bpf2a64_offset(i, off, ctx); check_imm26(jmp_offset); emit(A64_B(jmp_offset), ctx); break; @@ -669,7 +672,7 @@ emit_bswap_uxt: case BPF_JMP32 | BPF_JSLE | BPF_X: emit(A64_CMP(is64, dst, src), ctx); emit_cond_jmp: - jmp_offset = bpf2a64_offset(i + off, i, ctx); + jmp_offset = bpf2a64_offset(i, off, ctx); check_imm19(jmp_offset); switch (BPF_OP(code)) { case BPF_JEQ: @@ -908,10 +911,21 @@ static int build_body(struct jit_ctx *ctx, bool extra_pass) const struct bpf_prog *prog = ctx->prog; int i; + /* + * - offset[0] offset of the end of prologue, + * start of the 1st instruction. + * - offset[1] - offset of the end of 1st instruction, + * start of the 2nd instruction + * [....] + * - offset[3] - offset of the end of 3rd instruction, + * start of 4th instruction + */ for (i = 0; i < prog->len; i++) { const struct bpf_insn *insn = &prog->insnsi[i]; int ret; + if (ctx->image == NULL) + ctx->offset[i] = ctx->idx; ret = build_insn(insn, ctx, extra_pass); if (ret > 0) { i++; @@ -919,11 +933,16 @@ static int build_body(struct jit_ctx *ctx, bool extra_pass) ctx->offset[i] = ctx->idx; continue; } - if (ctx->image == NULL) - ctx->offset[i] = ctx->idx; if (ret) return ret; } + /* + * offset is allocated with prog->len + 1 so fill in + * the last element with the offset after the last + * instruction (end of program) + */ + if (ctx->image == NULL) + ctx->offset[i] = ctx->idx; return 0; } @@ -1002,7 +1021,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) memset(&ctx, 0, sizeof(ctx)); ctx.prog = prog; - ctx.offset = kcalloc(prog->len, sizeof(int), GFP_KERNEL); + ctx.offset = kcalloc(prog->len + 1, sizeof(int), GFP_KERNEL); if (ctx.offset == NULL) { prog = orig_prog; goto out_off; @@ -1089,7 +1108,7 @@ skip_init_ctx: prog->jited_len = prog_size; if (!prog->is_func || extra_pass) { - bpf_prog_fill_jited_linfo(prog, ctx.offset); + bpf_prog_fill_jited_linfo(prog, ctx.offset + 1); out_off: kfree(ctx.offset); kfree(jit_data); |