diff mbox series

[bpf-next,05/16] bpf: Disasm support for cast_kern/user instructions.

Message ID 20240206220441.38311-6-alexei.starovoitov@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: Introduce BPF arena. | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR fail PR summary
netdev/series_format fail Series longer than 15 patches (and no cover letter)
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 7798 this patch: 7798
netdev/build_tools success Errors and warnings before: 1 this patch: 1
netdev/cc_maintainers warning 14 maintainers not CCed: quentin@isovalent.com jolsa@kernel.org john.fastabend@gmail.com nathan@kernel.org yonghong.song@linux.dev song@kernel.org martin.lau@linux.dev sdf@google.com morbo@google.com justinstitt@google.com kpsingh@kernel.org ndesaulniers@google.com llvm@lists.linux.dev haoluo@google.com
netdev/build_clang success Errors and warnings before: 2369 this patch: 2369
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8294 this patch: 8294
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns WARNING: line length of 85 exceeds 80 columns WARNING: line length of 87 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Unittests
bpf/vmtest-bpf-next-VM_Test-0 success Logs for Lint
bpf/vmtest-bpf-next-VM_Test-3 success Logs for Validate matrix.py
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-5 success Logs for aarch64-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-4 fail Logs for aarch64-gcc / build / build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-6 success Logs for aarch64-gcc / test
bpf/vmtest-bpf-next-VM_Test-7 success Logs for aarch64-gcc / veristat
bpf/vmtest-bpf-next-VM_Test-9 success Logs for s390x-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-8 fail Logs for s390x-gcc / build / build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-10 success Logs for s390x-gcc / test
bpf/vmtest-bpf-next-VM_Test-11 success Logs for s390x-gcc / veristat
bpf/vmtest-bpf-next-VM_Test-12 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-13 fail Logs for x86_64-gcc / build / build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-14 success Logs for x86_64-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-15 success Logs for x86_64-gcc / test
bpf/vmtest-bpf-next-VM_Test-16 success Logs for x86_64-gcc / veristat
bpf/vmtest-bpf-next-VM_Test-17 fail Logs for x86_64-llvm-17 / build / build for x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-18 fail Logs for x86_64-llvm-17 / build-release / build for x86_64 with llvm-17 and -O2 optimization
bpf/vmtest-bpf-next-VM_Test-19 success Logs for x86_64-llvm-17 / test
bpf/vmtest-bpf-next-VM_Test-20 success Logs for x86_64-llvm-17 / veristat
bpf/vmtest-bpf-next-VM_Test-21 fail Logs for x86_64-llvm-18 / build / build for x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-22 fail Logs for x86_64-llvm-18 / build-release / build for x86_64 with llvm-18 and -O2 optimization
bpf/vmtest-bpf-next-VM_Test-23 success Logs for x86_64-llvm-18 / test
bpf/vmtest-bpf-next-VM_Test-24 success Logs for x86_64-llvm-18 / veristat

Commit Message

Alexei Starovoitov Feb. 6, 2024, 10:04 p.m. UTC 
From: Alexei Starovoitov <ast@kernel.org>

LLVM generates rX = bpf_cast_kern/_user(rY, address_space) instructions
when pointers in non-zero address space are used by the bpf program.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 include/uapi/linux/bpf.h       |  5 +++++
 kernel/bpf/disasm.c            | 11 +++++++++++
 tools/include/uapi/linux/bpf.h |  5 +++++
 3 files changed, 21 insertions(+)
diff mbox series

Patch

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index f6648851eae6..3de1581379d4 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1313,6 +1313,11 @@  enum {
  */
 #define BPF_PSEUDO_KFUNC_CALL	2
 
+enum bpf_arena_cast_kinds {
+	BPF_ARENA_CAST_KERN = 1,
+	BPF_ARENA_CAST_USER = 2,
+};
+
 /* flags for BPF_MAP_UPDATE_ELEM command */
 enum {
 	BPF_ANY		= 0, /* create new element or update existing */
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
index 49940c26a227..37d9b37b34f7 100644
--- a/kernel/bpf/disasm.c
+++ b/kernel/bpf/disasm.c
@@ -166,6 +166,12 @@  static bool is_movsx(const struct bpf_insn *insn)
 	       (insn->off == 8 || insn->off == 16 || insn->off == 32);
 }
 
+static bool is_arena_cast(const struct bpf_insn *insn)
+{
+	return insn->code == (BPF_ALU64 | BPF_MOV | BPF_X) &&
+		(insn->off == BPF_ARENA_CAST_KERN || insn->off == BPF_ARENA_CAST_USER);
+}
+
 void print_bpf_insn(const struct bpf_insn_cbs *cbs,
 		    const struct bpf_insn *insn,
 		    bool allow_ptr_leaks)
@@ -184,6 +190,11 @@  void print_bpf_insn(const struct bpf_insn_cbs *cbs,
 				insn->code, class == BPF_ALU ? 'w' : 'r',
 				insn->dst_reg, class == BPF_ALU ? 'w' : 'r',
 				insn->dst_reg);
+		} else if (is_arena_cast(insn)) {
+			verbose(cbs->private_data, "(%02x) r%d = cast_%s(r%d, %d)\n",
+				insn->code, insn->dst_reg,
+				insn->off == BPF_ARENA_CAST_KERN ? "kern" : "user",
+				insn->src_reg, insn->imm);
 		} else if (BPF_SRC(insn->code) == BPF_X) {
 			verbose(cbs->private_data, "(%02x) %c%d %s %s%c%d\n",
 				insn->code, class == BPF_ALU ? 'w' : 'r',
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index f6648851eae6..3de1581379d4 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1313,6 +1313,11 @@  enum {
  */
 #define BPF_PSEUDO_KFUNC_CALL	2
 
+enum bpf_arena_cast_kinds {
+	BPF_ARENA_CAST_KERN = 1,
+	BPF_ARENA_CAST_USER = 2,
+};
+
 /* flags for BPF_MAP_UPDATE_ELEM command */
 enum {
 	BPF_ANY		= 0, /* create new element or update existing */