aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/bpf/core.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--kernel/bpf/core.c186
1 files changed, 159 insertions, 27 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index f93ed667546f..5cdd8da0e7f2 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -105,6 +105,91 @@ struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
}
EXPORT_SYMBOL_GPL(bpf_prog_alloc);
+int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
+{
+ if (!prog->aux->nr_linfo || !prog->jit_requested)
+ return 0;
+
+ prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo,
+ sizeof(*prog->aux->jited_linfo),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!prog->aux->jited_linfo)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void bpf_prog_free_jited_linfo(struct bpf_prog *prog)
+{
+ kfree(prog->aux->jited_linfo);
+ prog->aux->jited_linfo = NULL;
+}
+
+void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog)
+{
+ if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0])
+ bpf_prog_free_jited_linfo(prog);
+}
+
+/* The jit engine is responsible to provide an array
+ * for insn_off to the jited_off mapping (insn_to_jit_off).
+ *
+ * The idx to this array is the insn_off. Hence, the insn_off
+ * here is relative to the prog itself instead of the main prog.
+ * This array has one entry for each xlated bpf insn.
+ *
+ * jited_off is the byte off to the last byte of the jited insn.
+ *
+ * Hence, with
+ * insn_start:
+ * The first bpf insn off of the prog. The insn off
+ * here is relative to the main prog.
+ * e.g. if prog is a subprog, insn_start > 0
+ * linfo_idx:
+ * The prog's idx to prog->aux->linfo and jited_linfo
+ *
+ * jited_linfo[linfo_idx] = prog->bpf_func
+ *
+ * For i > linfo_idx,
+ *
+ * jited_linfo[i] = prog->bpf_func +
+ * insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
+ */
+void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
+ const u32 *insn_to_jit_off)
+{
+ u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
+ const struct bpf_line_info *linfo;
+ void **jited_linfo;
+
+ if (!prog->aux->jited_linfo)
+ /* Userspace did not provide linfo */
+ return;
+
+ linfo_idx = prog->aux->linfo_idx;
+ linfo = &prog->aux->linfo[linfo_idx];
+ insn_start = linfo[0].insn_off;
+ insn_end = insn_start + prog->len;
+
+ jited_linfo = &prog->aux->jited_linfo[linfo_idx];
+ jited_linfo[0] = prog->bpf_func;
+
+ nr_linfo = prog->aux->nr_linfo - linfo_idx;
+
+ for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
+ /* The verifier ensures that linfo[i].insn_off is
+ * strictly increasing
+ */
+ jited_linfo[i] = prog->bpf_func +
+ insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
+}
+
+void bpf_prog_free_linfo(struct bpf_prog *prog)
+{
+ bpf_prog_free_jited_linfo(prog);
+ kvfree(prog->aux->linfo);
+}
+
struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
gfp_t gfp_extra_flags)
{
@@ -294,6 +379,26 @@ static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta,
return ret;
}
+static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
+{
+ struct bpf_line_info *linfo;
+ u32 i, nr_linfo;
+
+ nr_linfo = prog->aux->nr_linfo;
+ if (!nr_linfo || !delta)
+ return;
+
+ linfo = prog->aux->linfo;
+
+ for (i = 0; i < nr_linfo; i++)
+ if (off < linfo[i].insn_off)
+ break;
+
+ /* Push all off < linfo[i].insn_off by delta */
+ for (; i < nr_linfo; i++)
+ linfo[i].insn_off += delta;
+}
+
struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
const struct bpf_insn *patch, u32 len)
{
@@ -349,6 +454,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
*/
BUG_ON(bpf_adj_branches(prog_adj, off, insn_delta, false));
+ bpf_adj_linfo(prog_adj, off, insn_delta);
+
return prog_adj;
}
@@ -410,7 +517,7 @@ static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
sym = bin2hex(sym, prog->tag, sizeof(prog->tag));
/* prog->aux->name will be ignored if full btf name is available */
- if (prog->aux->btf) {
+ if (prog->aux->func_info_cnt) {
type = btf_type_by_id(prog->aux->btf,
prog->aux->func_info[prog->aux->func_idx].type_id);
func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
@@ -623,6 +730,16 @@ static void bpf_jit_uncharge_modmem(u32 pages)
atomic_long_sub(pages, &bpf_jit_current);
}
+void *__weak bpf_jit_alloc_exec(unsigned long size)
+{
+ return module_alloc(size);
+}
+
+void __weak bpf_jit_free_exec(void *addr)
+{
+ module_memfree(addr);
+}
+
struct bpf_binary_header *
bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
unsigned int alignment,
@@ -640,7 +757,7 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
if (bpf_jit_charge_modmem(pages))
return NULL;
- hdr = module_alloc(size);
+ hdr = bpf_jit_alloc_exec(size);
if (!hdr) {
bpf_jit_uncharge_modmem(pages);
return NULL;
@@ -664,7 +781,7 @@ void bpf_jit_binary_free(struct bpf_binary_header *hdr)
{
u32 pages = hdr->pages;
- module_memfree(hdr);
+ bpf_jit_free_exec(hdr);
bpf_jit_uncharge_modmem(pages);
}
@@ -923,32 +1040,34 @@ EXPORT_SYMBOL_GPL(__bpf_call_base);
#define BPF_INSN_MAP(INSN_2, INSN_3) \
/* 32 bit ALU operations. */ \
/* Register based. */ \
- INSN_3(ALU, ADD, X), \
- INSN_3(ALU, SUB, X), \
- INSN_3(ALU, AND, X), \
- INSN_3(ALU, OR, X), \
- INSN_3(ALU, LSH, X), \
- INSN_3(ALU, RSH, X), \
- INSN_3(ALU, XOR, X), \
- INSN_3(ALU, MUL, X), \
- INSN_3(ALU, MOV, X), \
- INSN_3(ALU, DIV, X), \
- INSN_3(ALU, MOD, X), \
+ INSN_3(ALU, ADD, X), \
+ INSN_3(ALU, SUB, X), \
+ INSN_3(ALU, AND, X), \
+ INSN_3(ALU, OR, X), \
+ INSN_3(ALU, LSH, X), \
+ INSN_3(ALU, RSH, X), \
+ INSN_3(ALU, XOR, X), \
+ INSN_3(ALU, MUL, X), \
+ INSN_3(ALU, MOV, X), \
+ INSN_3(ALU, ARSH, X), \
+ INSN_3(ALU, DIV, X), \
+ INSN_3(ALU, MOD, X), \
INSN_2(ALU, NEG), \
INSN_3(ALU, END, TO_BE), \
INSN_3(ALU, END, TO_LE), \
/* Immediate based. */ \
- INSN_3(ALU, ADD, K), \
- INSN_3(ALU, SUB, K), \
- INSN_3(ALU, AND, K), \
- INSN_3(ALU, OR, K), \
- INSN_3(ALU, LSH, K), \
- INSN_3(ALU, RSH, K), \
- INSN_3(ALU, XOR, K), \
- INSN_3(ALU, MUL, K), \
- INSN_3(ALU, MOV, K), \
- INSN_3(ALU, DIV, K), \
- INSN_3(ALU, MOD, K), \
+ INSN_3(ALU, ADD, K), \
+ INSN_3(ALU, SUB, K), \
+ INSN_3(ALU, AND, K), \
+ INSN_3(ALU, OR, K), \
+ INSN_3(ALU, LSH, K), \
+ INSN_3(ALU, RSH, K), \
+ INSN_3(ALU, XOR, K), \
+ INSN_3(ALU, MUL, K), \
+ INSN_3(ALU, MOV, K), \
+ INSN_3(ALU, ARSH, K), \
+ INSN_3(ALU, DIV, K), \
+ INSN_3(ALU, MOD, K), \
/* 64 bit ALU operations. */ \
/* Register based. */ \
INSN_3(ALU64, ADD, X), \
@@ -1127,6 +1246,12 @@ select_insn:
DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
insn++;
CONT;
+ ALU_ARSH_X:
+ DST = (u64) (u32) ((*(s32 *) &DST) >> SRC);
+ CONT;
+ ALU_ARSH_K:
+ DST = (u64) (u32) ((*(s32 *) &DST) >> IMM);
+ CONT;
ALU64_ARSH_X:
(*(s64 *) &DST) >>= SRC;
CONT;
@@ -1573,13 +1698,20 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
* be JITed, but falls back to the interpreter.
*/
if (!bpf_prog_is_dev_bound(fp->aux)) {
+ *err = bpf_prog_alloc_jited_linfo(fp);
+ if (*err)
+ return fp;
+
fp = bpf_int_jit_compile(fp);
-#ifdef CONFIG_BPF_JIT_ALWAYS_ON
if (!fp->jited) {
+ bpf_prog_free_jited_linfo(fp);
+#ifdef CONFIG_BPF_JIT_ALWAYS_ON
*err = -ENOTSUPP;
return fp;
- }
#endif
+ } else {
+ bpf_prog_free_unused_jited_linfo(fp);
+ }
} else {
*err = bpf_prog_offload_compile(fp);
if (*err)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.