[PATCH] Revert "bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro()" for linux-6.6.37

WangYuli
2024-07-06T03:13:05Z

This reverts commit 08f6c05feb1db21653e98ca84ea04ca032d014c7.

Upstream commit e60adf513275 ("bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro()")
depends on
upstream commit 1dad391daef1 ("bpf, arm64: use bpf_prog_pack for memory management").

It will cause a compilation warning on the arm64 if it's not merged:
arch/arm64/net/bpf_jit_comp.c: In function ‘bpf_int_jit_compile’:
arch/arm64/net/bpf_jit_comp.c:1651:17: warning: ignoring return value of ‘bpf_jit_binary_lock_ro’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
1651 | bpf_jit_binary_lock_ro(header);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This will prevent the kernel with the '-Werror' compile option from
being compiled successfully.

We might as well revert this commit in linux-6.6.37 to solve the
problem in a simple way.

Signed-off-by: WangYuli <wangyuli@uniontech.com>
---
arch/arm/net/bpf_jit_32.c | 25 +++++++++++++------------
arch/loongarch/net/bpf_jit.c | 22 ++++++----------------
arch/mips/net/bpf_jit_comp.c | 3 +--
arch/parisc/net/bpf_jit_core.c | 8 +-------
arch/s390/net/bpf_jit_comp.c | 6 +-----
arch/sparc/net/bpf_jit_comp_64.c | 6 +-----
arch/x86/net/bpf_jit_comp32.c | 3 ++-
include/linux/filter.h | 5 ++---
8 files changed, 27 insertions(+), 51 deletions(-)

diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index ac8e4d9bf954..6a1c9fca5260 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -1982,21 +1982,28 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
/* If building the body of the JITed code fails somehow,
* we fall back to the interpretation.
*/
- if (build_body(&ctx) < 0)
- goto out_free;
+ if (build_body(&ctx) < 0) {
+ image_ptr = NULL;
+ bpf_jit_binary_free(header);
+ prog = orig_prog;
+ goto out_imms;
+ }
build_epilogue(&ctx);

/* 3.) Extra pass to validate JITed Code */
- if (validate_code(&ctx))
- goto out_free;
+ if (validate_code(&ctx)) {
+ image_ptr = NULL;
+ bpf_jit_binary_free(header);
+ prog = orig_prog;
+ goto out_imms;
+ }
flush_icache_range((u32)header, (u32)(ctx.target + ctx.idx));

if (bpf_jit_enable > 1)
/* there are 2 passes here */
bpf_jit_dump(prog->len, image_size, 2, ctx.target);

- if (bpf_jit_binary_lock_ro(header))
- goto out_free;
+ bpf_jit_binary_lock_ro(header);
prog->bpf_func = (void *)ctx.target;
prog->jited = 1;
prog->jited_len = image_size;
@@ -2013,11 +2020,5 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
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/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index 13cd480385ca..9eb7753d117d 100644
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -1206,19 +1206,16 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
flush_icache_range((unsigned long)header, (unsigned long)(ctx.image + ctx.idx));

if (!prog->is_func || extra_pass) {
- int err;
-
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);
- goto out_free;
- }
- err = bpf_jit_binary_lock_ro(header);
- if (err) {
- pr_err_once("bpf_jit_binary_lock_ro() returned %d\n",
- err);
- goto out_free;
+ bpf_jit_binary_free(header);
+ prog->bpf_func = NULL;
+ prog->jited = 0;
+ prog->jited_len = 0;
+ goto out_offset;
}
+ bpf_jit_binary_lock_ro(header);
} else {
jit_data->ctx = ctx;
jit_data->image = image_ptr;
@@ -1249,13 +1246,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
out_offset = -1;

return prog;
-
-out_free:
- bpf_jit_binary_free(header);
- prog->bpf_func = NULL;
- prog->jited = 0;
- prog->jited_len = 0;
- goto out_offset;
}

/* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */
diff --git a/arch/mips/net/bpf_jit_comp.c b/arch/mips/net/bpf_jit_comp.c
index e355dfca4400..a40d926b6513 100644
--- a/arch/mips/net/bpf_jit_comp.c
+++ b/arch/mips/net/bpf_jit_comp.c
@@ -1012,8 +1012,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
bpf_prog_fill_jited_linfo(prog, &ctx.descriptors[1]);

/* Set as read-only exec and flush instruction cache */
- if (bpf_jit_binary_lock_ro(header))
- goto out_err;
+ bpf_jit_binary_lock_ro(header);
flush_icache_range((unsigned long)header,
(unsigned long)&ctx.target[ctx.jit_index]);

diff --git a/arch/parisc/net/bpf_jit_core.c b/arch/parisc/net/bpf_jit_core.c
index 979f45d4d1fb..d6ee2fd45550 100644
--- a/arch/parisc/net/bpf_jit_core.c
+++ b/arch/parisc/net/bpf_jit_core.c
@@ -167,13 +167,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
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;
- }
+ bpf_jit_binary_lock_ro(jit_data->header);
prologue_len = ctx->epilogue_offset - ctx->body_len;
for (i = 0; i < prog->len; i++)
ctx->offset[i] += prologue_len;
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 05746e22fe79..62ee557d4b49 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -1973,11 +1973,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
print_fn_code(jit.prg_buf, jit.size_prg);
}
if (!fp->is_func || extra_pass) {
- if (bpf_jit_binary_lock_ro(header)) {
- bpf_jit_binary_free(header);
- fp = orig_fp;
- goto free_addrs;
- }
+ bpf_jit_binary_lock_ro(header);
} else {
jit_data->header = header;
jit_data->ctx = jit;
diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c
index 73bf0aea8baf..fa0759bfe498 100644
--- a/arch/sparc/net/bpf_jit_comp_64.c
+++ b/arch/sparc/net/bpf_jit_comp_64.c
@@ -1602,11 +1602,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
bpf_flush_icache(header, (u8 *)header + header->size);

if (!prog->is_func || extra_pass) {
- if (bpf_jit_binary_lock_ro(header)) {
- bpf_jit_binary_free(header);
- prog = orig_prog;
- goto out_off;
- }
+ bpf_jit_binary_lock_ro(header);
} else {
jit_data->ctx = ctx;
jit_data->image = image_ptr;
diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
index f2fc8c38629b..429a89c5468b 100644
--- a/arch/x86/net/bpf_jit_comp32.c
+++ b/arch/x86/net/bpf_jit_comp32.c
@@ -2600,7 +2600,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
if (bpf_jit_enable > 1)
bpf_jit_dump(prog->len, proglen, pass + 1, image);

- if (image && !bpf_jit_binary_lock_ro(header)) {
+ if (image) {
+ bpf_jit_binary_lock_ro(header);
prog->bpf_func = (void *)image;
prog->jited = 1;
prog->jited_len = proglen;
diff --git a/include/linux/filter.h b/include/linux/filter.h
index a74d97114a54..5a2800ec94ea 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -853,11 +853,10 @@ static inline int __must_check bpf_prog_lock_ro(struct bpf_prog *fp)
return 0;
}

-static inline int __must_check
-bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
+static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
{
set_vm_flush_reset_perms(hdr);
- return set_memory_rox((unsigned long)hdr, hdr->size >> PAGE_SHIFT);
+ set_memory_rox((unsigned long)hdr, hdr->size >> PAGE_SHIFT);
}

int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
--
2.43.0