diff mbox series

[bpf-next,v2,7/8] bpftool: Support setting alternative arch for JIT disasm with LLVM

Message ID 20220911201451.12368-8-quentin@isovalent.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series bpftool: Add LLVM as default library for disassembling JIT-ed programs | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 5 maintainers not CCed: nathan@kernel.org llvm@lists.linux.dev trix@redhat.com ndesaulniers@google.com martin.lau@linux.dev
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
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: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 80 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
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bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_progs on s390x with gcc
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bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_progs_no_alu32 on s390x with gcc
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Commit Message

Quentin Monnet Sept. 11, 2022, 8:14 p.m. UTC
For offloaded BPF programs, instead of failing to create the
LLVM disassembler without even looking for a triple at all, do run the
function that attempts to retrieve a valid architecture name for the
device.

It will still fail for the LLVM disassembler, because currently we have
no valid triple to return (NFP disassembly is not supported by LLVM).
But failing in that function is more logical than to assume in
jit_disasm.c that passing an "arch" name is simply not supported.

Suggested-by: Song Liu <song@kernel.org>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
---
 tools/bpf/bpftool/common.c     | 10 ++++++----
 tools/bpf/bpftool/jit_disasm.c | 15 +++++++--------
 tools/bpf/bpftool/main.h       |  3 +--
 tools/bpf/bpftool/prog.c       |  6 ++----
 4 files changed, 16 insertions(+), 18 deletions(-)
diff mbox series

Patch

diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 4c2e909a2d67..e4d33bc8bbbf 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -627,12 +627,11 @@  static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
 }
 
 const char *
-ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
-		      const char **opt)
+ifindex_to_arch(__u32 ifindex, __u64 ns_dev, __u64 ns_ino, const char **opt)
 {
+	__maybe_unused int device_id;
 	char devname[IF_NAMESIZE];
 	int vendor_id;
-	int device_id;
 
 	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
 		p_err("Can't get net device name for ifindex %d: %s", ifindex,
@@ -647,6 +646,7 @@  ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
 	}
 
 	switch (vendor_id) {
+#ifdef HAVE_LIBBFD_SUPPORT
 	case 0x19ee:
 		device_id = read_sysfs_netdev_hex_int(devname, "device");
 		if (device_id != 0x4000 &&
@@ -655,8 +655,10 @@  ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
 			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
 		*opt = "ctx4";
 		return "NFP-6xxx";
+#endif /* HAVE_LIBBFD_SUPPORT */
+	/* No NFP support in LLVM, we have no valid triple to return. */
 	default:
-		p_err("Can't get bfd arch name for device vendor id 0x%04x",
+		p_err("Can't get arch name for device vendor id 0x%04x",
 		      vendor_id);
 		return NULL;
 	}
diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c
index c28b21f90cb9..58a5017034a2 100644
--- a/tools/bpf/bpftool/jit_disasm.c
+++ b/tools/bpf/bpftool/jit_disasm.c
@@ -84,12 +84,10 @@  init_context(disasm_ctx_t *ctx, const char *arch,
 {
 	char *triple;
 
-	if (arch) {
-		p_err("Architecture %s not supported", arch);
-		return -1;
-	}
-
-	triple = LLVMGetDefaultTargetTriple();
+	if (arch)
+		triple = LLVMNormalizeTargetTriple(arch);
+	else
+		triple = LLVMGetDefaultTargetTriple();
 	if (!triple) {
 		p_err("Failed to retrieve triple");
 		return -1;
@@ -128,8 +126,9 @@  disassemble_insn(disasm_ctx_t *ctx, unsigned char *image, ssize_t len, int pc)
 
 int disasm_init(void)
 {
-	LLVMInitializeNativeTarget();
-	LLVMInitializeNativeDisassembler();
+	LLVMInitializeAllTargetInfos();
+	LLVMInitializeAllTargetMCs();
+	LLVMInitializeAllDisassemblers();
 	return 0;
 }
 #endif /* HAVE_LLVM_SUPPORT */
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 9a149c67aa5d..467d8472df0c 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -203,8 +203,7 @@  void print_hex_data_json(uint8_t *data, size_t len);
 unsigned int get_page_size(void);
 unsigned int get_possible_cpus(void);
 const char *
-ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
-		      const char **opt);
+ifindex_to_arch(__u32 ifindex, __u64 ns_dev, __u64 ns_ino, const char **opt);
 
 struct btf_dumper {
 	const struct btf *btf;
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 345dca656a34..aa041ae8ec32 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -764,10 +764,8 @@  prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
 		const char *name = NULL;
 
 		if (info->ifindex) {
-			name = ifindex_to_bfd_params(info->ifindex,
-						     info->netns_dev,
-						     info->netns_ino,
-						     &disasm_opt);
+			name = ifindex_to_arch(info->ifindex, info->netns_dev,
+					       info->netns_ino, &disasm_opt);
 			if (!name)
 				goto exit_free;
 		}