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authorLinus Torvalds <torvalds@linux-foundation.org>2020-09-18 11:55:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-09-18 11:55:43 -0700
commit69828c475d15290553cb5512108424746baf6225 (patch)
treea2f1251918b9bb39836dd81f23342466990d7501 /arch
parent5a55d36f715b01a00c1ad7127a73044c6f1c9668 (diff)
parent75df529bec9110dad43ab30e2d9490242529e8b8 (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.c8
-rw-r--r--arch/arm64/kernel/paravirt.c26
-rw-r--r--arch/arm64/net/bpf_jit_comp.c43
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);