Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-01-05

We've added 40 non-merge commits during the last 2 day(s) which contain
a total of 73 files changed, 1526 insertions(+), 951 deletions(-).

The main changes are:

1) Fix a memory leak when streaming AF_UNIX sockets were inserted
   into multiple sockmap slots/maps, from John Fastabend.

2) Fix gotol in s390 BPF JIT with large offsets, from Ilya Leoshkevich.

3) Fix reattachment branch in bpf_tracing_prog_attach() and reject
   the request if there is no valid attach_btf, from Jiri Olsa.

4) Remove deprecated bpfilter kernel leftovers given the project
   is developed in user space (https://github.com/facebook/bpfilter),
   from Quentin Deslandes.

5) Relax tracing BPF program recursive attach rules given right now
   it is not possible to create tracing program call cycles,
   from Dmitrii Dolgov.

6) Fix excessive memory consumption for the bpf_global_percpu_ma
   for systems with a large number of CPUs, from Yonghong Song.

7) Small x86 BPF JIT cleanup to reuse emit_nops instead of open-coding
   memcpy of x86_nops, from Leon Hwang.

8) Follow-up for libbpf to support __arg_ctx global function argument tag
   semantics to complement the merged kernel side, from Andrii Nakryiko.

9) Introduce "volatile compare" macros for BPF selftests in order
   to make the latter more robust against compiler optimization,
   from Alexei Starovoitov.

10) Small simplification in verifier's size checking of helper accesses
    along with additional selftests, from Andrei Matei.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (40 commits)
  selftests/bpf: Test re-attachment fix for bpf_tracing_prog_attach
  bpf: Fix re-attachment branch in bpf_tracing_prog_attach
  selftests/bpf: Add test for recursive attachment of tracing progs
  bpf: Relax tracing prog recursive attach rules
  bpf, x86: Use emit_nops to replace memcpy x86_nops
  selftests/bpf: Test gotol with large offsets
  selftests/bpf: Double the size of test_loader log
  s390/bpf: Fix gotol with large offsets
  bpfilter: remove bpfilter
  bpf: Remove unnecessary cpu == 0 check in memalloc
  selftests/bpf: add __arg_ctx BTF rewrite test
  selftests/bpf: add arg:ctx cases to test_global_funcs tests
  libbpf: implement __arg_ctx fallback logic
  libbpf: move BTF loading step after relocation step
  libbpf: move exception callbacks assignment logic into relocation step
  libbpf: use stable map placeholder FDs
  libbpf: don't rely on map->fd as an indicator of map being created
  libbpf: use explicit map reuse flag to skip map creation steps
  libbpf: make uniform use of btf__fd() accessor inside libbpf
  selftests/bpf: Add a selftest with > 512-byte percpu allocation size
  ...
====================

Link: https://lore.kernel.org/r/20240105170105.21070-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 22 insertions, 25 deletions

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index bdacbb84456d..fe30b9ebb8de 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -307,6 +307,25 @@ static void pop_callee_regs(u8 **pprog, bool *callee_regs_used)
 	*pprog = prog;
 }
 
+static void emit_nops(u8 **pprog, int len)
+{
+	u8 *prog = *pprog;
+	int i, noplen;
+
+	while (len > 0) {
+		noplen = len;
+
+		if (noplen > ASM_NOP_MAX)
+			noplen = ASM_NOP_MAX;
+
+		for (i = 0; i < noplen; i++)
+			EMIT1(x86_nops[noplen][i]);
+		len -= noplen;
+	}
+
+	*pprog = prog;
+}
+
 /*
  * Emit the various CFI preambles, see asm/cfi.h and the comments about FineIBT
  * in arch/x86/kernel/alternative.c
@@ -385,8 +404,7 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf,
 	/* BPF trampoline can be made to work without these nops,
 	 * but let's waste 5 bytes for now and optimize later
 	 */
-	memcpy(prog, x86_nops[5], X86_PATCH_SIZE);
-	prog += X86_PATCH_SIZE;
+	emit_nops(&prog, X86_PATCH_SIZE);
 	if (!ebpf_from_cbpf) {
 		if (tail_call_reachable && !is_subprog)
 			/* When it's the entry of the whole tailcall context,
@@ -692,8 +710,7 @@ static void emit_bpf_tail_call_direct(struct bpf_prog *bpf_prog,
 	if (stack_depth)
 		EMIT3_off32(0x48, 0x81, 0xC4, round_up(stack_depth, 8));
 
-	memcpy(prog, x86_nops[5], X86_PATCH_SIZE);
-	prog += X86_PATCH_SIZE;
+	emit_nops(&prog, X86_PATCH_SIZE);
 
 	/* out: */
 	ctx->tail_call_direct_label = prog - start;
@@ -1055,25 +1072,6 @@ static void detect_reg_usage(struct bpf_insn *insn, int insn_cnt,
 	}
 }
 
-static void emit_nops(u8 **pprog, int len)
-{
-	u8 *prog = *pprog;
-	int i, noplen;
-
-	while (len > 0) {
-		noplen = len;
-
-		if (noplen > ASM_NOP_MAX)
-			noplen = ASM_NOP_MAX;
-
-		for (i = 0; i < noplen; i++)
-			EMIT1(x86_nops[noplen][i]);
-		len -= noplen;
-	}
-
-	*pprog = prog;
-}
-
 /* emit the 3-byte VEX prefix
  *
  * r: same as rex.r, extra bit for ModRM reg field
@@ -2700,8 +2698,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im
 		/* remember return value in a stack for bpf prog to access */
 		emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8);
 		im->ip_after_call = image + (prog - (u8 *)rw_image);
-		memcpy(prog, x86_nops[5], X86_PATCH_SIZE);
-		prog += X86_PATCH_SIZE;
+		emit_nops(&prog, X86_PATCH_SIZE);
 	}
 
 	if (fmod_ret->nr_links) {