[PATCH bpf v15 1/5] bpf: Move constants blinding out of arch-specific JITs

Xu Kuohai
2026-04-16T07:05:17Z

During the JIT stage, constants blinding rewrites instructions but only
rewrites the private instruction copy of the JITed subprog, leaving the
global env->prog->insnsi and env->insn_aux_data untouched. This causes a
mismatch between subprog instructions and the global state, making it
difficult to use the global data in the JIT.

To avoid this mismatch, and given that all arch-specific JITs already
support constants blinding, move it to the generic verifier code, and
switch to rewrite the global env->prog->insnsi with the global states
adjusted, as other rewrites in the verifier do.

This removes the constants blinding calls in each JIT, which are largely
duplicated code across architectures.

Since constants blinding is only required for JIT, and there are two
JIT entry functions, jit_subprogs() for BPF programs with multiple
subprogs and bpf_prog_select_runtime() for programs with no subprogs,
move the constants blinding invocation into these two functions.

In the verifier path, bpf_patch_insn_data() is used to keep global
verifier auxiliary data in sync with patched instructions. A key
question is whether this global auxiliary data should be restored
on the failure path.

Besides instructions, bpf_patch_insn_data() adjusts:
- prog->aux->poke_tab
- env->insn_array_maps
- env->subprog_info
- env->insn_aux_data

For prog->aux->poke_tab, it is only used by JIT or only meaningful after
JIT succeeds, so it does not need to be restored on the failure path.

For env->insn_array_maps, when JIT fails, programs using insn arrays
are rejected by bpf_insn_array_ready() due to missing JIT addresses.
Hence, env->insn_array_maps is only meaningful for JIT and does not need
to be restored.

For subprog_info, if jit_subprogs fails and CONFIG_BPF_JIT_ALWAYS_ON
is not enabled, kernel falls back to interpreter. In this case,
env->subprog_info is used to determine subprogram stack depth. So it
must be restored on failure.

For env->insn_aux_data, it is freed by clear_insn_aux_data() at the
end of bpf_check(). Before freeing, clear_insn_aux_data() loops over
env->insn_aux_data to release jump targets recorded in it. The loop
uses env->prog->len as the array length, but this length no longer
matches the actual size of the adjusted env->insn_aux_data array after
constants blinding.

To address it, a simple approach is to keep insn_aux_data as adjusted
after failure, since it will be freed shortly, and record its actual size
for the loop in clear_insn_aux_data(). But since clear_insn_aux_data()
uses the same index to loop over both env->prog->insnsi and env->insn_aux_data,
this approach results in incorrect index for the insnsi array. So an
alternative approach is adopted: clone the original env->insn_aux_data
before blinding and restore it after failure, similar to env->prog.

For classic BPF programs, constants blinding works as before since it
is still invoked from bpf_prog_select_runtime().

Reviewed-by: Anton Protopopov <a.s.protopopov@gmail.com> # v8
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> # powerpc jit
Reviewed-by: Pu Lehui <pulehui@huawei.com> # riscv jit
Acked-by: Hengqi Chen <hengqi.chen@gmail.com> # loongarch jit
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
---
arch/arc/net/bpf_jit_core.c | 39 +++------
arch/arm/net/bpf_jit_32.c | 41 ++-------
arch/arm64/net/bpf_jit_comp.c | 72 +++++----------
arch/loongarch/net/bpf_jit.c | 59 ++++---------
arch/mips/net/bpf_jit_comp.c | 20 +----
arch/parisc/net/bpf_jit_core.c | 73 ++++++----------
arch/powerpc/net/bpf_jit_comp.c | 72 ++++++---------
arch/riscv/net/bpf_jit_core.c | 61 +++++--------
arch/s390/net/bpf_jit_comp.c | 59 +++++--------
arch/sparc/net/bpf_jit_comp_64.c | 61 +++++--------
arch/x86/net/bpf_jit_comp.c | 43 ++-------
arch/x86/net/bpf_jit_comp32.c | 33 +------
include/linux/filter.h | 33 ++++++-
kernel/bpf/core.c | 69 +++++++++++++--
kernel/bpf/fixups.c | 146 ++++++++++++++++++++++++++-----
15 files changed, 403 insertions(+), 478 deletions(-)

diff --git a/arch/arc/net/bpf_jit_core.c b/arch/arc/net/bpf_jit_core.c
index 1421eeced0f5..973ceae48675 100644
--- a/arch/arc/net/bpf_jit_core.c
+++ b/arch/arc/net/bpf_jit_core.c
@@ -79,7 +79,6 @@ struct arc_jit_data {
* The JIT pertinent context that is used by different functions.
*
* prog: The current eBPF program being handled.
- * orig_prog: The original eBPF program before any possible change.
* jit: The JIT buffer and its length.
* bpf_header: The JITed program header. "jit.buf" points inside it.
* emit: If set, opcodes are written to memory; else, a dry-run.
@@ -94,12 +93,10 @@ struct arc_jit_data {
* need_extra_pass: A forecast if an "extra_pass" will occur.
* is_extra_pass: Indicates if the current pass is an extra pass.
* user_bpf_prog: True, if VM opcodes come from a real program.
- * blinded: True if "constant blinding" step returned a new "prog".
* success: Indicates if the whole JIT went OK.
*/
struct jit_context {
struct bpf_prog *prog;
- struct bpf_prog *orig_prog;
struct jit_buffer jit;
struct bpf_binary_header *bpf_header;
bool emit;
@@ -114,7 +111,6 @@ struct jit_context {
bool need_extra_pass;
bool is_extra_pass;
bool user_bpf_prog;
- bool blinded;
bool success;
};

@@ -161,13 +157,7 @@ static int jit_ctx_init(struct jit_context *ctx, struct bpf_prog *prog)
{
memset(ctx, 0, sizeof(*ctx));

- ctx->orig_prog = prog;
-
- /* If constant blinding was requested but failed, scram. */
- ctx->prog = bpf_jit_blind_constants(prog);
- if (IS_ERR(ctx->prog))
- return PTR_ERR(ctx->prog);
- ctx->blinded = (ctx->prog != ctx->orig_prog);
+ ctx->prog = prog;

/* If the verifier doesn't zero-extend, then we have to do it. */
ctx->do_zext = !ctx->prog->aux->verifier_zext;
@@ -214,14 +204,6 @@ static inline void maybe_free(struct jit_context *ctx, void **mem)
*/
static void jit_ctx_cleanup(struct jit_context *ctx)
{
- if (ctx->blinded) {
- /* if all went well, release the orig_prog. */
- if (ctx->success)
- bpf_jit_prog_release_other(ctx->prog, ctx->orig_prog);
- else
- bpf_jit_prog_release_other(ctx->orig_prog, ctx->prog);
- }
-
maybe_free(ctx, (void **)&ctx->bpf2insn);
maybe_free(ctx, (void **)&ctx->jit_data);

@@ -229,12 +211,19 @@ static void jit_ctx_cleanup(struct jit_context *ctx)
ctx->bpf2insn_valid = false;

/* Freeing "bpf_header" is enough. "jit.buf" is a sub-array of it. */
- if (!ctx->success && ctx->bpf_header) {
- bpf_jit_binary_free(ctx->bpf_header);
- ctx->bpf_header = NULL;
- ctx->jit.buf = NULL;
- ctx->jit.index = 0;
- ctx->jit.len = 0;
+ if (!ctx->success) {
+ if (ctx->bpf_header) {
+ bpf_jit_binary_free(ctx->bpf_header);
+ ctx->bpf_header = NULL;
+ ctx->jit.buf = NULL;
+ ctx->jit.index = 0;
+ ctx->jit.len = 0;
+ }
+ if (ctx->is_extra_pass) {
+ ctx->prog->bpf_func = NULL;
+ ctx->prog->jited = 0;
+ ctx->prog->jited_len = 0;
+ }
}

ctx->emit = false;
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index deeb8f292454..e6b1bb2de627 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -2144,9 +2144,7 @@ bool bpf_jit_needs_zext(void)

struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
- struct bpf_prog *tmp, *orig_prog = prog;
struct bpf_binary_header *header;
- bool tmp_blinded = false;
struct jit_ctx ctx;
unsigned int tmp_idx;
unsigned int image_size;
@@ -2156,20 +2154,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
* the interpreter.
*/
if (!prog->jit_requested)
- return orig_prog;
-
- /* If constant blinding was enabled and we failed during blinding
- * then we must fall back to the interpreter. Otherwise, we save
- * the new JITed code.
- */
- tmp = bpf_jit_blind_constants(prog);
-
- if (IS_ERR(tmp))
- return orig_prog;
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

memset(&ctx, 0, sizeof(ctx));
ctx.prog = prog;
@@ -2179,10 +2164,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
* we must fall back to the interpreter
*/
ctx.offsets = kcalloc(prog->len, sizeof(int), GFP_KERNEL);
- if (ctx.offsets == NULL) {
- prog = orig_prog;
- goto out;
- }
+ if (ctx.offsets == NULL)
+ return prog;

/* 1) fake pass to find in the length of the JITed code,
* to compute ctx->offsets and other context variables
@@ -2194,10 +2177,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
* being successful in the second pass, so just fall back
* to the interpreter.
*/
- if (build_body(&ctx)) {
- prog = orig_prog;
+ if (build_body(&ctx))
goto out_off;
- }

tmp_idx = ctx.idx;
build_prologue(&ctx);
@@ -2213,10 +2194,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ctx.idx += ctx.imm_count;
if (ctx.imm_count) {
ctx.imms = kcalloc(ctx.imm_count, sizeof(u32), GFP_KERNEL);
- if (ctx.imms == NULL) {
- prog = orig_prog;
+ if (ctx.imms == NULL)
goto out_off;
- }
}
#else
/* there's nothing about the epilogue on ARMv7 */
@@ -2238,10 +2217,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
/* Not able to allocate memory for the structure then
* we must fall back to the interpretation
*/
- if (header == NULL) {
- prog = orig_prog;
+ if (header == NULL)
goto out_imms;
- }

/* 2.) Actual pass to generate final JIT code */
ctx.target = (u32 *) image_ptr;
@@ -2278,16 +2255,12 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
#endif
out_off:
kfree(ctx.offsets);
-out:
- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ?
- tmp : orig_prog);
+
return prog;

out_free:
image_ptr = NULL;
bpf_jit_binary_free(header);
- prog = orig_prog;
goto out_imms;
}

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 524b67c0867e..d310d1c35192 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -2003,14 +2003,12 @@ struct arm64_jit_data {
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
int image_size, prog_size, extable_size, extable_align, extable_offset;
- struct bpf_prog *tmp, *orig_prog = prog;
struct bpf_binary_header *header;
struct bpf_binary_header *ro_header = NULL;
struct arm64_jit_data *jit_data;
void __percpu *priv_stack_ptr = NULL;
bool was_classic = bpf_prog_was_classic(prog);
int priv_stack_alloc_sz;
- bool tmp_blinded = false;
bool extra_pass = false;
struct jit_ctx ctx;
u8 *image_ptr;
@@ -2019,26 +2017,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
int exentry_idx;

if (!prog->jit_requested)
- return orig_prog;
-
- tmp = bpf_jit_blind_constants(prog);
- /* If blinding was requested and we failed during blinding,
- * we must fall back to the interpreter.
- */
- if (IS_ERR(tmp))
- return orig_prog;
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

jit_data = prog->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc_obj(*jit_data);
- if (!jit_data) {
- prog = orig_prog;
- goto out;
- }
+ if (!jit_data)
+ return prog;
prog->aux->jit_data = jit_data;
}
priv_stack_ptr = prog->aux->priv_stack_ptr;
@@ -2050,10 +2035,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
priv_stack_alloc_sz = round_up(prog->aux->stack_depth, 16) +
2 * PRIV_STACK_GUARD_SZ;
priv_stack_ptr = __alloc_percpu_gfp(priv_stack_alloc_sz, 16, GFP_KERNEL);
- if (!priv_stack_ptr) {
- prog = orig_prog;
+ if (!priv_stack_ptr)
goto out_priv_stack;
- }

priv_stack_init_guard(priv_stack_ptr, priv_stack_alloc_sz);
prog->aux->priv_stack_ptr = priv_stack_ptr;
@@ -2073,10 +2056,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ctx.prog = prog;

ctx.offset = kvzalloc_objs(int, prog->len + 1);
- if (ctx.offset == NULL) {
- prog = orig_prog;
+ if (ctx.offset == NULL)
goto out_off;
- }

ctx.user_vm_start = bpf_arena_get_user_vm_start(prog->aux->arena);
ctx.arena_vm_start = bpf_arena_get_kern_vm_start(prog->aux->arena);
@@ -2089,15 +2070,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
* BPF line info needs ctx->offset[i] to be the offset of
* instruction[i] in jited image, so build prologue first.
*/
- if (build_prologue(&ctx, was_classic)) {
- prog = orig_prog;
+ if (build_prologue(&ctx, was_classic))
goto out_off;
- }

- if (build_body(&ctx, extra_pass)) {
- prog = orig_prog;
+ if (build_body(&ctx, extra_pass))
goto out_off;
- }

ctx.epilogue_offset = ctx.idx;
build_epilogue(&ctx, was_classic);
@@ -2115,10 +2092,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ro_header = bpf_jit_binary_pack_alloc(image_size, &ro_image_ptr,
sizeof(u64), &header, &image_ptr,
jit_fill_hole);
- if (!ro_header) {
- prog = orig_prog;
+ if (!ro_header)
goto out_off;
- }

/* Pass 2: Determine jited position and result for each instruction */

@@ -2146,10 +2121,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
/* Dont write body instructions to memory for now */
ctx.write = false;

- if (build_body(&ctx, extra_pass)) {
- prog = orig_prog;
+ if (build_body(&ctx, extra_pass))
goto out_free_hdr;
- }

ctx.epilogue_offset = ctx.idx;
ctx.exentry_idx = exentry_idx;
@@ -2158,19 +2131,15 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)

/* Pass 3: Adjust jump offset and write final image */
if (build_body(&ctx, extra_pass) ||
- WARN_ON_ONCE(ctx.idx != ctx.epilogue_offset)) {
- prog = orig_prog;
+ WARN_ON_ONCE(ctx.idx != ctx.epilogue_offset))
goto out_free_hdr;
- }

build_epilogue(&ctx, was_classic);
build_plt(&ctx);

/* Extra pass to validate JITed code. */
- if (validate_ctx(&ctx)) {
- prog = orig_prog;
+ if (validate_ctx(&ctx))
goto out_free_hdr;
- }

/* update the real prog size */
prog_size = sizeof(u32) * ctx.idx;
@@ -2187,16 +2156,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
if (extra_pass && ctx.idx > jit_data->ctx.idx) {
pr_err_once("multi-func JIT bug %d > %d\n",
ctx.idx, jit_data->ctx.idx);
- prog->bpf_func = NULL;
- prog->jited = 0;
- prog->jited_len = 0;
goto out_free_hdr;
}
if (WARN_ON(bpf_jit_binary_pack_finalize(ro_header, header))) {
- /* ro_header has been freed */
+ /* ro_header and header has been freed */
ro_header = NULL;
- prog = orig_prog;
- goto out_off;
+ header = NULL;
+ goto out_free_hdr;
}
} else {
jit_data->ctx = ctx;
@@ -2233,13 +2199,15 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
kfree(jit_data);
prog->aux->jit_data = NULL;
}
-out:
- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ?
- tmp : orig_prog);
+
return prog;

out_free_hdr:
+ if (extra_pass) {
+ prog->bpf_func = NULL;
+ prog->jited = 0;
+ prog->jited_len = 0;
+ }
if (header) {
bpf_arch_text_copy(&ro_header->size, &header->size,
sizeof(header->size));
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index 9cb796e16379..fcc8c0c29fb0 100644
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -1922,43 +1922,26 @@ int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,

struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
- bool tmp_blinded = false, extra_pass = false;
+ bool extra_pass = false;
u8 *image_ptr, *ro_image_ptr;
int image_size, prog_size, extable_size;
struct jit_ctx ctx;
struct jit_data *jit_data;
struct bpf_binary_header *header;
struct bpf_binary_header *ro_header;
- struct bpf_prog *tmp, *orig_prog = prog;

/*
* If BPF JIT was not enabled then we must fall back to
* the interpreter.
*/
if (!prog->jit_requested)
- return orig_prog;
-
- tmp = bpf_jit_blind_constants(prog);
- /*
- * If blinding was requested and we failed during blinding,
- * we must fall back to the interpreter. Otherwise, we save
- * the new JITed code.
- */
- if (IS_ERR(tmp))
- return orig_prog;
-
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

jit_data = prog->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc_obj(*jit_data);
- if (!jit_data) {
- prog = orig_prog;
- goto out;
- }
+ if (!jit_data)
+ return prog;
prog->aux->jit_data = jit_data;
}
if (jit_data->ctx.offset) {
@@ -1978,17 +1961,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ctx.user_vm_start = bpf_arena_get_user_vm_start(prog->aux->arena);

ctx.offset = kvcalloc(prog->len + 1, sizeof(u32), GFP_KERNEL);
- if (ctx.offset == NULL) {
- prog = orig_prog;
+ if (ctx.offset == NULL)
goto out_offset;
- }

/* 1. Initial fake pass to compute ctx->idx and set ctx->flags */
build_prologue(&ctx);
- if (build_body(&ctx, extra_pass)) {
- prog = orig_prog;
+ if (build_body(&ctx, extra_pass))
goto out_offset;
- }
ctx.epilogue_offset = ctx.idx;
build_epilogue(&ctx);

@@ -2004,10 +1983,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
/* Now we know the size of the structure to make */
ro_header = bpf_jit_binary_pack_alloc(image_size, &ro_image_ptr, sizeof(u32),
&header, &image_ptr, jit_fill_hole);
- if (!ro_header) {
- prog = orig_prog;
+ if (!ro_header)
goto out_offset;
- }

/* 2. Now, the actual pass to generate final JIT code */
/*
@@ -2027,17 +2004,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ctx.num_exentries = 0;

build_prologue(&ctx);
- if (build_body(&ctx, extra_pass)) {
- prog = orig_prog;
+ if (build_body(&ctx, extra_pass))
goto out_free;
- }
build_epilogue(&ctx);

/* 3. Extra pass to validate JITed code */
- if (validate_ctx(&ctx)) {
- prog = orig_prog;
+ if (validate_ctx(&ctx))
goto out_free;
- }

/* And we're done */
if (bpf_jit_enable > 1)
@@ -2050,9 +2023,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
goto out_free;
}
if (WARN_ON(bpf_jit_binary_pack_finalize(ro_header, header))) {
- /* ro_header has been freed */
+ /* ro_header and header have been freed */
ro_header = NULL;
- prog = orig_prog;
+ header = NULL;
goto out_free;
}
/*
@@ -2084,13 +2057,15 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
prog->aux->jit_data = NULL;
}

-out:
- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog);
-
return prog;

out_free:
+ if (extra_pass) {
+ prog->bpf_func = NULL;
+ prog->jited = 0;
+ prog->jited_len = 0;
+ }
+
if (header) {
bpf_arch_text_copy(&ro_header->size, &header->size, sizeof(header->size));
bpf_jit_binary_pack_free(ro_header, header);
diff --git a/arch/mips/net/bpf_jit_comp.c b/arch/mips/net/bpf_jit_comp.c
index e355dfca4400..d2b6c955f18e 100644
--- a/arch/mips/net/bpf_jit_comp.c
+++ b/arch/mips/net/bpf_jit_comp.c
@@ -911,10 +911,8 @@ bool bpf_jit_needs_zext(void)

struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
- struct bpf_prog *tmp, *orig_prog = prog;
struct bpf_binary_header *header = NULL;
struct jit_context ctx;
- bool tmp_blinded = false;
unsigned int tmp_idx;
unsigned int image_size;
u8 *image_ptr;
@@ -925,19 +923,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
* the interpreter.
*/
if (!prog->jit_requested)
- return orig_prog;
- /*
- * If constant blinding was enabled and we failed during blinding
- * then we must fall back to the interpreter. Otherwise, we save
- * the new JITed code.
- */
- tmp = bpf_jit_blind_constants(prog);
- if (IS_ERR(tmp))
- return orig_prog;
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

memset(&ctx, 0, sizeof(ctx));
ctx.program = prog;
@@ -1025,14 +1011,10 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
prog->jited_len = image_size;

out:
- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ?
- tmp : orig_prog);
kfree(ctx.descriptors);
return prog;

out_err:
- prog = orig_prog;
if (header)
bpf_jit_binary_free(header);
goto out;
diff --git a/arch/parisc/net/bpf_jit_core.c b/arch/parisc/net/bpf_jit_core.c
index a5eb6b51e27a..35dca372b5df 100644
--- a/arch/parisc/net/bpf_jit_core.c
+++ b/arch/parisc/net/bpf_jit_core.c
@@ -44,30 +44,19 @@ bool bpf_jit_needs_zext(void)
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
unsigned int prog_size = 0, extable_size = 0;
- bool tmp_blinded = false, extra_pass = false;
- struct bpf_prog *tmp, *orig_prog = prog;
+ bool extra_pass = false;
int pass = 0, prev_ninsns = 0, prologue_len, i;
struct hppa_jit_data *jit_data;
struct hppa_jit_context *ctx;

if (!prog->jit_requested)
- return orig_prog;
-
- tmp = bpf_jit_blind_constants(prog);
- if (IS_ERR(tmp))
- return orig_prog;
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

jit_data = prog->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc_obj(*jit_data);
- if (!jit_data) {
- prog = orig_prog;
- goto out;
- }
+ if (!jit_data)
+ return prog;
prog->aux->jit_data = jit_data;
}

@@ -81,10 +70,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)

ctx->prog = prog;
ctx->offset = kzalloc_objs(int, prog->len);
- if (!ctx->offset) {
- prog = orig_prog;
- goto out_offset;
- }
+ if (!ctx->offset)
+ goto out_err;
for (i = 0; i < prog->len; i++) {
prev_ninsns += 20;
ctx->offset[i] = prev_ninsns;
@@ -93,10 +80,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
for (i = 0; i < NR_JIT_ITERATIONS; i++) {
pass++;
ctx->ninsns = 0;
- if (build_body(ctx, extra_pass, ctx->offset)) {
- prog = orig_prog;
- goto out_offset;
- }
+ if (build_body(ctx, extra_pass, ctx->offset))
+ goto out_err;
ctx->body_len = ctx->ninsns;
bpf_jit_build_prologue(ctx);
ctx->prologue_len = ctx->ninsns - ctx->body_len;
@@ -116,10 +101,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
&jit_data->image,
sizeof(long),
bpf_fill_ill_insns);
- if (!jit_data->header) {
- prog = orig_prog;
- goto out_offset;
- }
+ if (!jit_data->header)
+ goto out_err;

ctx->insns = (u32 *)jit_data->image;
/*
@@ -134,8 +117,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
pr_err("bpf-jit: image did not converge in <%d passes!\n", i);
if (jit_data->header)
bpf_jit_binary_free(jit_data->header);
- prog = orig_prog;
- goto out_offset;
+ goto out_err;
}

if (extable_size)
@@ -148,8 +130,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
bpf_jit_build_prologue(ctx);
if (build_body(ctx, extra_pass, NULL)) {
bpf_jit_binary_free(jit_data->header);
- prog = orig_prog;
- goto out_offset;
+ goto out_err;
}
bpf_jit_build_epilogue(ctx);

@@ -160,20 +141,19 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{ extern int machine_restart(char *); machine_restart(""); }
}

+ if (!prog->is_func || extra_pass) {
+ if (bpf_jit_binary_lock_ro(jit_data->header)) {
+ bpf_jit_binary_free(jit_data->header);
+ goto out_err;
+ }
+ bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns);
+ }
+
prog->bpf_func = (void *)ctx->insns;
prog->jited = 1;
prog->jited_len = prog_size;

- bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns);
-
if (!prog->is_func || extra_pass) {
- if (bpf_jit_binary_lock_ro(jit_data->header)) {
- bpf_jit_binary_free(jit_data->header);
- prog->bpf_func = NULL;
- prog->jited = 0;
- prog->jited_len = 0;
- goto out_offset;
- }
prologue_len = ctx->epilogue_offset - ctx->body_len;
for (i = 0; i < prog->len; i++)
ctx->offset[i] += prologue_len;
@@ -183,14 +163,19 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
kfree(jit_data);
prog->aux->jit_data = NULL;
}
-out:
+
if (HPPA_JIT_REBOOT)
{ extern int machine_restart(char *); machine_restart(""); }

- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ?
- tmp : orig_prog);
return prog;
+
+out_err:
+ if (extra_pass) {
+ prog->bpf_func = NULL;
+ prog->jited = 0;
+ prog->jited_len = 0;
+ }
+ goto out_offset;
}

u64 hppa_div64(u64 div, u64 divisor)
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 50103b3794fb..2bae4699e78f 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -177,9 +177,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
void __percpu *priv_stack_ptr = NULL;
struct bpf_binary_header *fhdr = NULL;
struct bpf_binary_header *hdr = NULL;
- struct bpf_prog *org_fp = fp;
- struct bpf_prog *tmp_fp = NULL;
- bool bpf_blinded = false;
bool extra_pass = false;
u8 *fimage = NULL;
u32 *fcode_base = NULL;
@@ -187,24 +184,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
u32 fixup_len;

if (!fp->jit_requested)
- return org_fp;
-
- tmp_fp = bpf_jit_blind_constants(org_fp);
- if (IS_ERR(tmp_fp))
- return org_fp;
-
- if (tmp_fp != org_fp) {
- bpf_blinded = true;
- fp = tmp_fp;
- }
+ return fp;

jit_data = fp->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc_obj(*jit_data);
- if (!jit_data) {
- fp = org_fp;
- goto out;
- }
+ if (!jit_data)
+ return fp;
fp->aux->jit_data = jit_data;
}

@@ -219,10 +205,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
priv_stack_alloc_size = round_up(fp->aux->stack_depth, 16) +
2 * PRIV_STACK_GUARD_SZ;
priv_stack_ptr = __alloc_percpu_gfp(priv_stack_alloc_size, 16, GFP_KERNEL);
- if (!priv_stack_ptr) {
- fp = org_fp;
+ if (!priv_stack_ptr)
goto out_priv_stack;
- }

priv_stack_init_guard(priv_stack_ptr, priv_stack_alloc_size);
fp->aux->priv_stack_ptr = priv_stack_ptr;
@@ -249,10 +233,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
}

addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL);
- if (addrs == NULL) {
- fp = org_fp;
- goto out_addrs;
- }
+ if (addrs == NULL)
+ goto out_err;

memset(&cgctx, 0, sizeof(struct codegen_context));
bpf_jit_init_reg_mapping(&cgctx);
@@ -279,11 +261,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
}

/* Scouting faux-generate pass 0 */
- if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) {
+ if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false))
/* We hit something illegal or unsupported. */
- fp = org_fp;
- goto out_addrs;
- }
+ goto out_err;

/*
* If we have seen a tail call, we need a second pass.
@@ -294,10 +274,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
*/
if (cgctx.seen & SEEN_TAILCALL || !is_offset_in_branch_range((long)cgctx.idx * 4)) {
cgctx.idx = 0;
- if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) {
- fp = org_fp;
- goto out_addrs;
- }
+ if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false))
+ goto out_err;
}

bpf_jit_realloc_regs(&cgctx);
@@ -318,10 +296,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)

fhdr = bpf_jit_binary_pack_alloc(alloclen, &fimage, 4, &hdr, &image,
bpf_jit_fill_ill_insns);
- if (!fhdr) {
- fp = org_fp;
- goto out_addrs;
- }
+ if (!fhdr)
+ goto out_err;

if (extable_len)
fp->aux->extable = (void *)fimage + FUNCTION_DESCR_SIZE + proglen + fixup_len;
@@ -340,8 +316,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
extra_pass)) {
bpf_arch_text_copy(&fhdr->size, &hdr->size, sizeof(hdr->size));
bpf_jit_binary_pack_free(fhdr, hdr);
- fp = org_fp;
- goto out_addrs;
+ goto out_err;
}
bpf_jit_build_epilogue(code_base, &cgctx);

@@ -363,15 +338,16 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
((u64 *)image)[1] = local_paca->kernel_toc;
#endif

+ if (!fp->is_func || extra_pass) {
+ if (bpf_jit_binary_pack_finalize(fhdr, hdr))
+ goto out_err;
+ }
+
fp->bpf_func = (void *)fimage;
fp->jited = 1;
fp->jited_len = cgctx.idx * 4 + FUNCTION_DESCR_SIZE;

if (!fp->is_func || extra_pass) {
- if (bpf_jit_binary_pack_finalize(fhdr, hdr)) {
- fp = org_fp;
- goto out_addrs;
- }
bpf_prog_fill_jited_linfo(fp, addrs);
/*
* On ABI V1, executable code starts after the function
@@ -398,11 +374,15 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
jit_data->hdr = hdr;
}

-out:
- if (bpf_blinded)
- bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp);
-
return fp;
+
+out_err:
+ if (extra_pass) {
+ fp->bpf_func = NULL;
+ fp->jited = 0;
+ fp->jited_len = 0;
+ }
+ goto out_addrs;
}

/*
diff --git a/arch/riscv/net/bpf_jit_core.c b/arch/riscv/net/bpf_jit_core.c
index f7fd4afc3ca3..36f0aea8096d 100644
--- a/arch/riscv/net/bpf_jit_core.c
+++ b/arch/riscv/net/bpf_jit_core.c
@@ -44,29 +44,19 @@ bool bpf_jit_needs_zext(void)
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
unsigned int prog_size = 0, extable_size = 0;
- bool tmp_blinded = false, extra_pass = false;
- struct bpf_prog *tmp, *orig_prog = prog;
+ bool extra_pass = false;
int pass = 0, prev_ninsns = 0, i;
struct rv_jit_data *jit_data;
struct rv_jit_context *ctx;

if (!prog->jit_requested)
- return orig_prog;
-
- tmp = bpf_jit_blind_constants(prog);
- if (IS_ERR(tmp))
- return orig_prog;
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

jit_data = prog->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc_obj(*jit_data);
if (!jit_data) {
- prog = orig_prog;
- goto out;
+ return prog;
}
prog->aux->jit_data = jit_data;
}
@@ -83,15 +73,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ctx->user_vm_start = bpf_arena_get_user_vm_start(prog->aux->arena);
ctx->prog = prog;
ctx->offset = kzalloc_objs(int, prog->len);
- if (!ctx->offset) {
- prog = orig_prog;
+ if (!ctx->offset)
goto out_offset;
- }

- if (build_body(ctx, extra_pass, NULL)) {
- prog = orig_prog;
+ if (build_body(ctx, extra_pass, NULL))
goto out_offset;
- }

for (i = 0; i < prog->len; i++) {
prev_ninsns += 32;
@@ -105,10 +91,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
bpf_jit_build_prologue(ctx, bpf_is_subprog(prog));
ctx->prologue_len = ctx->ninsns;

- if (build_body(ctx, extra_pass, ctx->offset)) {
- prog = orig_prog;
+ if (build_body(ctx, extra_pass, ctx->offset))
goto out_offset;
- }

ctx->epilogue_offset = ctx->ninsns;
bpf_jit_build_epilogue(ctx);
@@ -126,10 +110,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
&jit_data->ro_image, sizeof(u32),
&jit_data->header, &jit_data->image,
bpf_fill_ill_insns);
- if (!jit_data->ro_header) {
- prog = orig_prog;
+ if (!jit_data->ro_header)
goto out_offset;
- }

/*
* Use the image(RW) for writing the JITed instructions. But also save
@@ -150,7 +132,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)

if (i == NR_JIT_ITERATIONS) {
pr_err("bpf-jit: image did not converge in <%d passes!\n", i);
- prog = orig_prog;
goto out_free_hdr;
}

@@ -163,26 +144,27 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ctx->nexentries = 0;

bpf_jit_build_prologue(ctx, bpf_is_subprog(prog));
- if (build_body(ctx, extra_pass, NULL)) {
- prog = orig_prog;
+ if (build_body(ctx, extra_pass, NULL))
goto out_free_hdr;
- }
bpf_jit_build_epilogue(ctx);

if (bpf_jit_enable > 1)
bpf_jit_dump(prog->len, prog_size, pass, ctx->insns);

- prog->bpf_func = (void *)ctx->ro_insns + cfi_get_offset();
- prog->jited = 1;
- prog->jited_len = prog_size - cfi_get_offset();
-
if (!prog->is_func || extra_pass) {
if (WARN_ON(bpf_jit_binary_pack_finalize(jit_data->ro_header, jit_data->header))) {
/* ro_header has been freed */
jit_data->ro_header = NULL;
- prog = orig_prog;
- goto out_offset;
+ jit_data->header = NULL;
+ goto out_free_hdr;
}
+ }
+
+ prog->bpf_func = (void *)ctx->ro_insns + cfi_get_offset();
+ prog->jited = 1;
+ prog->jited_len = prog_size - cfi_get_offset();
+
+ if (!prog->is_func || extra_pass) {
for (i = 0; i < prog->len; i++)
ctx->offset[i] = ninsns_rvoff(ctx->offset[i]);
bpf_prog_fill_jited_linfo(prog, ctx->offset);
@@ -191,14 +173,15 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
kfree(jit_data);
prog->aux->jit_data = NULL;
}
-out:

- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ?
- tmp : orig_prog);
return prog;

out_free_hdr:
+ if (extra_pass) {
+ prog->bpf_func = NULL;
+ prog->jited = 0;
+ prog->jited_len = 0;
+ }
if (jit_data->header) {
bpf_arch_text_copy(&jit_data->ro_header->size, &jit_data->header->size,
sizeof(jit_data->header->size));
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index d08d159b6319..2dfc279b1be2 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -2314,36 +2314,20 @@ static struct bpf_binary_header *bpf_jit_alloc(struct bpf_jit *jit,
*/
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
{
- struct bpf_prog *tmp, *orig_fp = fp;
struct bpf_binary_header *header;
struct s390_jit_data *jit_data;
- bool tmp_blinded = false;
bool extra_pass = false;
struct bpf_jit jit;
int pass;

if (!fp->jit_requested)
- return orig_fp;
-
- tmp = bpf_jit_blind_constants(fp);
- /*
- * If blinding was requested and we failed during blinding,
- * we must fall back to the interpreter.
- */
- if (IS_ERR(tmp))
- return orig_fp;
- if (tmp != fp) {
- tmp_blinded = true;
- fp = tmp;
- }
+ return fp;

jit_data = fp->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc_obj(*jit_data);
- if (!jit_data) {
- fp = orig_fp;
- goto out;
- }
+ if (!jit_data)
+ return fp;
fp->aux->jit_data = jit_data;
}
if (jit_data->ctx.addrs) {
@@ -2356,34 +2340,27 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)

memset(&jit, 0, sizeof(jit));
jit.addrs = kvcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
- if (jit.addrs == NULL) {
- fp = orig_fp;
- goto free_addrs;
- }
+ if (jit.addrs == NULL)
+ goto out_err;
/*
* Three initial passes:
* - 1/2: Determine clobbered registers
* - 3: Calculate program size and addrs array
*/
for (pass = 1; pass <= 3; pass++) {
- if (bpf_jit_prog(&jit, fp, extra_pass)) {
- fp = orig_fp;
- goto free_addrs;
- }
+ if (bpf_jit_prog(&jit, fp, extra_pass))
+ goto out_err;
}
/*
* Final pass: Allocate and generate program
*/
header = bpf_jit_alloc(&jit, fp);
- if (!header) {
- fp = orig_fp;
- goto free_addrs;
- }
+ if (!header)
+ goto out_err;
skip_init_ctx:
if (bpf_jit_prog(&jit, fp, extra_pass)) {
bpf_jit_binary_free(header);
- fp = orig_fp;
- goto free_addrs;
+ goto out_err;
}
if (bpf_jit_enable > 1) {
bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
@@ -2392,8 +2369,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
if (!fp->is_func || extra_pass) {
if (bpf_jit_binary_lock_ro(header)) {
bpf_jit_binary_free(header);
- fp = orig_fp;
- goto free_addrs;
+ goto out_err;
}
} else {
jit_data->header = header;
@@ -2411,11 +2387,16 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
kfree(jit_data);
fp->aux->jit_data = NULL;
}
-out:
- if (tmp_blinded)
- bpf_jit_prog_release_other(fp, fp == orig_fp ?
- tmp : orig_fp);
+
return fp;
+
+out_err:
+ if (extra_pass) {
+ fp->bpf_func = NULL;
+ fp->jited = 0;
+ fp->jited_len = 0;
+ }
+ goto free_addrs;
}

bool bpf_jit_supports_kfunc_call(void)
diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c
index b23d1c645ae5..e83e29137566 100644
--- a/arch/sparc/net/bpf_jit_comp_64.c
+++ b/arch/sparc/net/bpf_jit_comp_64.c
@@ -1479,37 +1479,22 @@ struct sparc64_jit_data {

struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
- struct bpf_prog *tmp, *orig_prog = prog;
struct sparc64_jit_data *jit_data;
struct bpf_binary_header *header;
u32 prev_image_size, image_size;
- bool tmp_blinded = false;
bool extra_pass = false;
struct jit_ctx ctx;
u8 *image_ptr;
int pass, i;

if (!prog->jit_requested)
- return orig_prog;
-
- tmp = bpf_jit_blind_constants(prog);
- /* If blinding was requested and we failed during blinding,
- * we must fall back to the interpreter.
- */
- if (IS_ERR(tmp))
- return orig_prog;
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

jit_data = prog->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc_obj(*jit_data);
- if (!jit_data) {
- prog = orig_prog;
- goto out;
- }
+ if (!jit_data)
+ return prog;
prog->aux->jit_data = jit_data;
}
if (jit_data->ctx.offset) {
@@ -1527,10 +1512,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ctx.prog = prog;

ctx.offset = kmalloc_array(prog->len, sizeof(unsigned int), GFP_KERNEL);
- if (ctx.offset == NULL) {
- prog = orig_prog;
- goto out_off;
- }
+ if (ctx.offset == NULL)
+ goto out_err;

/* Longest sequence emitted is for bswap32, 12 instructions. Pre-cook
* the offset array so that we converge faster.
@@ -1543,10 +1526,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
ctx.idx = 0;

build_prologue(&ctx);
- if (build_body(&ctx)) {
- prog = orig_prog;
- goto out_off;
- }
+ if (build_body(&ctx))
+ goto out_err;
build_epilogue(&ctx);

if (bpf_jit_enable > 1)
@@ -1569,10 +1550,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
image_size = sizeof(u32) * ctx.idx;
header = bpf_jit_binary_alloc(image_size, &image_ptr,
sizeof(u32), jit_fill_hole);
- if (header == NULL) {
- prog = orig_prog;
- goto out_off;
- }
+ if (header == NULL)
+ goto out_err;

ctx.image = (u32 *)image_ptr;
skip_init_ctx:
@@ -1582,8 +1561,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)

if (build_body(&ctx)) {
bpf_jit_binary_free(header);
- prog = orig_prog;
- goto out_off;
+ goto out_err;
}

build_epilogue(&ctx);
@@ -1592,8 +1570,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
pr_err("bpf_jit: Failed to converge, prev_size=%u size=%d\n",
prev_image_size, ctx.idx * 4);
bpf_jit_binary_free(header);
- prog = orig_prog;
- goto out_off;
+ goto out_err;
}

if (bpf_jit_enable > 1)
@@ -1604,8 +1581,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
if (!prog->is_func || extra_pass) {
if (bpf_jit_binary_lock_ro(header)) {
bpf_jit_binary_free(header);
- prog = orig_prog;
- goto out_off;
+ goto out_err;
}
} else {
jit_data->ctx = ctx;
@@ -1624,9 +1600,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
kfree(jit_data);
prog->aux->jit_data = NULL;
}
-out:
- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ?
- tmp : orig_prog);
+
return prog;
+
+out_err:
+ if (extra_pass) {
+ prog->bpf_func = NULL;
+ prog->jited = 0;
+ prog->jited_len = 0;
+ }
+ goto out_off;
}
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index e9b78040d703..77d00a8dec87 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -3717,13 +3717,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
struct bpf_binary_header *rw_header = NULL;
struct bpf_binary_header *header = NULL;
- struct bpf_prog *tmp, *orig_prog = prog;
void __percpu *priv_stack_ptr = NULL;
struct x64_jit_data *jit_data;
int priv_stack_alloc_sz;
int proglen, oldproglen = 0;
struct jit_context ctx = {};
- bool tmp_blinded = false;
bool extra_pass = false;
bool padding = false;
u8 *rw_image = NULL;
@@ -3733,27 +3731,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
int i;

if (!prog->jit_requested)
- return orig_prog;
-
- tmp = bpf_jit_blind_constants(prog);
- /*
- * If blinding was requested and we failed during blinding,
- * we must fall back to the interpreter.
- */
- if (IS_ERR(tmp))
- return orig_prog;
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

jit_data = prog->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc_obj(*jit_data);
- if (!jit_data) {
- prog = orig_prog;
- goto out;
- }
+ if (!jit_data)
+ return prog;
prog->aux->jit_data = jit_data;
}
priv_stack_ptr = prog->aux->priv_stack_ptr;
@@ -3765,10 +3749,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
priv_stack_alloc_sz = round_up(prog->aux->stack_depth, 8) +
2 * PRIV_STACK_GUARD_SZ;
priv_stack_ptr = __alloc_percpu_gfp(priv_stack_alloc_sz, 8, GFP_KERNEL);
- if (!priv_stack_ptr) {
- prog = orig_prog;
+ if (!priv_stack_ptr)
goto out_priv_stack;
- }

priv_stack_init_guard(priv_stack_ptr, priv_stack_alloc_sz);
prog->aux->priv_stack_ptr = priv_stack_ptr;
@@ -3786,10 +3768,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
goto skip_init_addrs;
}
addrs = kvmalloc_objs(*addrs, prog->len + 1);
- if (!addrs) {
- prog = orig_prog;
+ if (!addrs)
goto out_addrs;
- }

/*
* Before first pass, make a rough estimation of addrs[]
@@ -3820,8 +3800,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
sizeof(rw_header->size));
bpf_jit_binary_pack_free(header, rw_header);
}
- /* Fall back to interpreter mode */
- prog = orig_prog;
if (extra_pass) {
prog->bpf_func = NULL;
prog->jited = 0;
@@ -3852,10 +3830,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
header = bpf_jit_binary_pack_alloc(roundup(proglen, align) + extable_size,
&image, align, &rw_header, &rw_image,
jit_fill_hole);
- if (!header) {
- prog = orig_prog;
+ if (!header)
goto out_addrs;
- }
prog->aux->extable = (void *) image + roundup(proglen, align);
}
oldproglen = proglen;
@@ -3908,8 +3884,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
prog->bpf_func = (void *)image + cfi_get_offset();
prog->jited = 1;
prog->jited_len = proglen - cfi_get_offset();
- } else {
- prog = orig_prog;
}

if (!image || !prog->is_func || extra_pass) {
@@ -3925,10 +3899,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
kfree(jit_data);
prog->aux->jit_data = NULL;
}
-out:
- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ?
- tmp : orig_prog);
+
return prog;
}

diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
index dda423025c3d..5f259577614a 100644
--- a/arch/x86/net/bpf_jit_comp32.c
+++ b/arch/x86/net/bpf_jit_comp32.c
@@ -2521,35 +2521,19 @@ bool bpf_jit_needs_zext(void)
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
struct bpf_binary_header *header = NULL;
- struct bpf_prog *tmp, *orig_prog = prog;
int proglen, oldproglen = 0;
struct jit_context ctx = {};
- bool tmp_blinded = false;
u8 *image = NULL;
int *addrs;
int pass;
int i;

if (!prog->jit_requested)
- return orig_prog;
-
- tmp = bpf_jit_blind_constants(prog);
- /*
- * If blinding was requested and we failed during blinding,
- * we must fall back to the interpreter.
- */
- if (IS_ERR(tmp))
- return orig_prog;
- if (tmp != prog) {
- tmp_blinded = true;
- prog = tmp;
- }
+ return prog;

addrs = kmalloc_objs(*addrs, prog->len);
- if (!addrs) {
- prog = orig_prog;
- goto out;
- }
+ if (!addrs)
+ return prog;

/*
* Before first pass, make a rough estimation of addrs[]
@@ -2574,7 +2558,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
image = NULL;
if (header)
bpf_jit_binary_free(header);
- prog = orig_prog;
goto out_addrs;
}
if (image) {
@@ -2588,10 +2571,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
if (proglen == oldproglen) {
header = bpf_jit_binary_alloc(proglen, &image,
1, jit_fill_hole);
- if (!header) {
- prog = orig_prog;
+ if (!header)
goto out_addrs;
- }
}
oldproglen = proglen;
cond_resched();
@@ -2604,16 +2585,10 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
prog->bpf_func = (void *)image;
prog->jited = 1;
prog->jited_len = proglen;
- } else {
- prog = orig_prog;
}

out_addrs:
kfree(addrs);
-out:
- if (tmp_blinded)
- bpf_jit_prog_release_other(prog, prog == orig_prog ?
- tmp : orig_prog);
return prog;
}

diff --git a/include/linux/filter.h b/include/linux/filter.h
index f552170eacf4..9fa4d4090093 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1184,6 +1184,18 @@ static inline bool bpf_dump_raw_ok(const struct cred *cred)

struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
const struct bpf_insn *patch, u32 len);
+
+#ifdef CONFIG_BPF_SYSCALL
+struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 off,
+ const struct bpf_insn *patch, u32 len);
+#else
+static inline struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 off,
+ const struct bpf_insn *patch, u32 len)
+{
+ return ERR_PTR(-ENOTSUPP);
+}
+#endif /* CONFIG_BPF_SYSCALL */
+
int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt);

static inline bool xdp_return_frame_no_direct(void)
@@ -1310,9 +1322,14 @@ int bpf_jit_get_func_addr(const struct bpf_prog *prog,

const char *bpf_jit_get_prog_name(struct bpf_prog *prog);

-struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
+struct bpf_prog *bpf_jit_blind_constants(struct bpf_verifier_env *env, struct bpf_prog *prog);
void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);

+static inline bool bpf_prog_need_blind(const struct bpf_prog *prog)
+{
+ return prog->blinding_requested && !prog->blinded;
+}
+
static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
u32 pass, void *image)
{
@@ -1451,6 +1468,20 @@ static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
{
}

+static inline bool bpf_prog_need_blind(const struct bpf_prog *prog)
+{
+ return false;
+}
+
+static inline
+struct bpf_prog *bpf_jit_blind_constants(struct bpf_verifier_env *env, struct bpf_prog *prog)
+{
+ return prog;
+}
+
+static inline void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
+{
+}
#endif /* CONFIG_BPF_JIT */

void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 066b86e7233c..fc9fb3c07866 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1508,7 +1508,11 @@ static void adjust_insn_arrays(struct bpf_prog *prog, u32 off, u32 len)
#endif
}

-struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
+/*
+ * Now this function is used only to blind the main prog and must be invoked only when
+ * bpf_prog_need_blind() returns true.
+ */
+struct bpf_prog *bpf_jit_blind_constants(struct bpf_verifier_env *env, struct bpf_prog *prog)
{
struct bpf_insn insn_buff[16], aux[2];
struct bpf_prog *clone, *tmp;
@@ -1516,13 +1520,17 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
struct bpf_insn *insn;
int i, rewritten;

- if (!prog->blinding_requested || prog->blinded)
- return prog;
+ if (WARN_ON_ONCE(env && env->prog != prog))
+ return ERR_PTR(-EINVAL);

clone = bpf_prog_clone_create(prog, GFP_USER);
if (!clone)
return ERR_PTR(-ENOMEM);

+ /* make sure bpf_patch_insn_data() patches the correct prog */
+ if (env)
+ env->prog = clone;
+
insn_cnt = clone->len;
insn = clone->insnsi;

@@ -1550,21 +1558,35 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
if (!rewritten)
continue;

- tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
- if (IS_ERR(tmp)) {
+ if (env)
+ tmp = bpf_patch_insn_data(env, i, insn_buff, rewritten);
+ else
+ tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
+
+ if (IS_ERR_OR_NULL(tmp)) {
+ if (env)
+ /* restore the original prog */
+ env->prog = prog;
/* Patching may have repointed aux->prog during
* realloc from the original one, so we need to
* fix it up here on error.
*/
bpf_jit_prog_release_other(prog, clone);
- return tmp;
+ return IS_ERR(tmp) ? tmp : ERR_PTR(-ENOMEM);
}

clone = tmp;
insn_delta = rewritten - 1;

- /* Instructions arrays must be updated using absolute xlated offsets */
- adjust_insn_arrays(clone, prog->aux->subprog_start + i, rewritten);
+ if (env)
+ env->prog = clone;
+ else
+ /*
+ * Instructions arrays must be updated using absolute xlated offsets.
+ * The arrays have already been adjusted by bpf_patch_insn_data() when
+ * env is not NULL.
+ */
+ adjust_insn_arrays(clone, i, rewritten);

/* Walk new program and skip insns we just inserted. */
insn = clone->insnsi + i + insn_delta;
@@ -2533,6 +2555,35 @@ static bool bpf_prog_select_interpreter(struct bpf_prog *fp)
return select_interpreter;
}

+static struct bpf_prog *bpf_prog_jit_compile(struct bpf_prog *prog)
+{
+#ifdef CONFIG_BPF_JIT
+ struct bpf_prog *orig_prog;
+
+ if (!bpf_prog_need_blind(prog))
+ return bpf_int_jit_compile(prog);
+
+ orig_prog = prog;
+ prog = bpf_jit_blind_constants(NULL, prog);
+ /*
+ * If blinding was requested and we failed during blinding, we must fall
+ * back to the interpreter.
+ */
+ if (IS_ERR(prog))
+ return orig_prog;
+
+ prog = bpf_int_jit_compile(prog);
+ if (prog->jited) {
+ bpf_jit_prog_release_other(prog, orig_prog);
+ return prog;
+ }
+
+ bpf_jit_prog_release_other(orig_prog, prog);
+ prog = orig_prog;
+#endif
+ return prog;
+}
+
/**
* bpf_prog_select_runtime - select exec runtime for BPF program
* @fp: bpf_prog populated with BPF program
@@ -2572,7 +2623,7 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
if (*err)
return fp;

- fp = bpf_int_jit_compile(fp);
+ fp = bpf_prog_jit_compile(fp);
bpf_prog_jit_attempt_done(fp);
if (!fp->jited && jit_needed) {
*err = -ENOTSUPP;
diff --git a/kernel/bpf/fixups.c b/kernel/bpf/fixups.c
index dd00a680e4ea..721b830b5ef2 100644
--- a/kernel/bpf/fixups.c
+++ b/kernel/bpf/fixups.c
@@ -232,8 +232,8 @@ static void adjust_poke_descs(struct bpf_prog *prog, u32 off, u32 len)
}
}

-static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 off,
- const struct bpf_insn *patch, u32 len)
+struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 off,
+ const struct bpf_insn *patch, u32 len)
{
struct bpf_prog *new_prog;
struct bpf_insn_aux_data *new_data = NULL;
@@ -973,7 +973,47 @@ int bpf_convert_ctx_accesses(struct bpf_verifier_env *env)
return 0;
}

-int bpf_jit_subprogs(struct bpf_verifier_env *env)
+static u32 *bpf_dup_subprog_starts(struct bpf_verifier_env *env)
+{
+ u32 *starts = NULL;
+
+ starts = kvmalloc_objs(u32, env->subprog_cnt, GFP_KERNEL_ACCOUNT);
+ if (starts) {
+ for (int i = 0; i < env->subprog_cnt; i++)
+ starts[i] = env->subprog_info[i].start;
+ }
+ return starts;
+}
+
+static void bpf_restore_subprog_starts(struct bpf_verifier_env *env, u32 *orig_starts)
+{
+ for (int i = 0; i < env->subprog_cnt; i++)
+ env->subprog_info[i].start = orig_starts[i];
+ /* restore the start of fake 'exit' subprog as well */
+ env->subprog_info[env->subprog_cnt].start = env->prog->len;
+}
+
+static struct bpf_insn_aux_data *bpf_dup_insn_aux_data(struct bpf_verifier_env *env)
+{
+ size_t size;
+ void *new_aux;
+
+ size = array_size(sizeof(struct bpf_insn_aux_data), env->prog->len);
+ new_aux = __vmalloc(size, GFP_KERNEL_ACCOUNT);
+ if (new_aux)
+ memcpy(new_aux, env->insn_aux_data, size);
+ return new_aux;
+}
+
+static void bpf_restore_insn_aux_data(struct bpf_verifier_env *env,
+ struct bpf_insn_aux_data *orig_insn_aux)
+{
+ /* the expanded elements are zero-filled, so no special handling is required */
+ vfree(env->insn_aux_data);
+ env->insn_aux_data = orig_insn_aux;
+}
+
+static int jit_subprogs(struct bpf_verifier_env *env)
{
struct bpf_prog *prog = env->prog, **func, *tmp;
int i, j, subprog_start, subprog_end = 0, len, subprog;
@@ -981,10 +1021,6 @@ int bpf_jit_subprogs(struct bpf_verifier_env *env)
struct bpf_insn *insn;
void *old_bpf_func;
int err, num_exentries;
- int old_len, subprog_start_adjustment = 0;
-
- if (env->subprog_cnt <= 1)
- return 0;

for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
if (!bpf_pseudo_func(insn) && !bpf_pseudo_call(insn))
@@ -1053,10 +1089,11 @@ int bpf_jit_subprogs(struct bpf_verifier_env *env)
goto out_free;
func[i]->is_func = 1;
func[i]->sleepable = prog->sleepable;
+ func[i]->blinded = prog->blinded;
func[i]->aux->func_idx = i;
/* Below members will be freed only at prog->aux */
func[i]->aux->btf = prog->aux->btf;
- func[i]->aux->subprog_start = subprog_start + subprog_start_adjustment;
+ func[i]->aux->subprog_start = subprog_start;
func[i]->aux->func_info = prog->aux->func_info;
func[i]->aux->func_info_cnt = prog->aux->func_info_cnt;
func[i]->aux->poke_tab = prog->aux->poke_tab;
@@ -1113,15 +1150,7 @@ int bpf_jit_subprogs(struct bpf_verifier_env *env)
func[i]->aux->token = prog->aux->token;
if (!i)
func[i]->aux->exception_boundary = env->seen_exception;
-
- /*
- * To properly pass the absolute subprog start to jit
- * all instruction adjustments should be accumulated
- */
- old_len = func[i]->len;
func[i] = bpf_int_jit_compile(func[i]);
- subprog_start_adjustment += func[i]->len - old_len;
-
if (!func[i]->jited) {
err = -ENOTSUPP;
goto out_free;
@@ -1247,16 +1276,87 @@ int bpf_jit_subprogs(struct bpf_verifier_env *env)
}
kfree(func);
out_undo_insn:
+ bpf_prog_jit_attempt_done(prog);
+ return err;
+}
+
+int bpf_jit_subprogs(struct bpf_verifier_env *env)
+{
+ int err, i;
+ bool blinded = false;
+ struct bpf_insn *insn;
+ struct bpf_prog *prog, *orig_prog;
+ struct bpf_insn_aux_data *orig_insn_aux;
+ u32 *orig_subprog_starts;
+
+ if (env->subprog_cnt <= 1)
+ return 0;
+
+ prog = orig_prog = env->prog;
+ if (bpf_prog_need_blind(prog)) {
+ orig_insn_aux = bpf_dup_insn_aux_data(env);
+ if (!orig_insn_aux) {
+ err = -ENOMEM;
+ goto out_cleanup;
+ }
+ orig_subprog_starts = bpf_dup_subprog_starts(env);
+ if (!orig_subprog_starts) {
+ vfree(orig_insn_aux);
+ err = -ENOMEM;
+ goto out_cleanup;
+ }
+ prog = bpf_jit_blind_constants(env, prog);
+ if (IS_ERR(prog)) {
+ err = -ENOMEM;
+ prog = orig_prog;
+ goto out_restore;
+ }
+ blinded = true;
+ }
+
+ err = jit_subprogs(env);
+ if (err)
+ goto out_jit_err;
+
+ if (blinded) {
+ bpf_jit_prog_release_other(prog, orig_prog);
+ kvfree(orig_subprog_starts);
+ vfree(orig_insn_aux);
+ }
+
+ return 0;
+
+out_jit_err:
+ if (blinded) {
+ bpf_jit_prog_release_other(orig_prog, prog);
+ /* roll back to the clean original prog */
+ prog = env->prog = orig_prog;
+ goto out_restore;
+ } else {
+ if (err != -EFAULT) {
+ /*
+ * We will fall back to interpreter mode when err is not -EFAULT, before
+ * that, insn->off and insn->imm should be restored to their original
+ * values since they were modified by jit_subprogs.
+ */
+ for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
+ if (!bpf_pseudo_call(insn))
+ continue;
+ insn->off = 0;
+ insn->imm = env->insn_aux_data[i].call_imm;
+ }
+ }
+ goto out_cleanup;
+ }
+
+out_restore:
+ bpf_restore_subprog_starts(env, orig_subprog_starts);
+ bpf_restore_insn_aux_data(env, orig_insn_aux);
+ kvfree(orig_subprog_starts);
+out_cleanup:
/* cleanup main prog to be interpreted */
prog->jit_requested = 0;
prog->blinding_requested = 0;
- for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
- if (!bpf_pseudo_call(insn))
- continue;
- insn->off = 0;
- insn->imm = env->insn_aux_data[i].call_imm;
- }
- bpf_prog_jit_attempt_done(prog);
return err;
}

--
2.43.0