DLPX-88975 update-package failed with a merge conflict in the drgn br…

…anch

PR URL: https://www.github.com/delphix/drgn/pull/58

.github/workflows/ci.yml

@@ -45,14 +45,21 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
           allow-prereleases: true
+      - name: Check Python version for pre-commit
+        # Only run pre-commit / mypy on upstream supported Python versions
+        run: |
+          if [[ "${{ matrix.python-version }}" =~ ^3\.([89]|[0-9][0-9])$ ]]; then
+              echo USE_PRE_COMMIT=1 >> $GITHUB_ENV
+          fi
       - name: Install dependencies
         run: |
           sudo apt-get update
           sudo apt-get install dwarves libelf-dev libdw-dev qemu-kvm zstd ${{ matrix.cc == 'clang' && 'libomp-$(clang --version | sed -rn "s/.*clang version ([0-9]+).*/\\1/p")-dev' || '' }}
-          pip install pyroute2 pre-commit
+          pip install pyroute2 ${USE_PRE_COMMIT/1/pre-commit}
       - name: Generate version.py
         run: python setup.py --version
       - name: Check with mypy
+        if: ${{ env.USE_PRE_COMMIT == '1' }}
         run: pre-commit run --all-files mypy
       - name: Build and test with ${{ matrix.cc }}
         run: CONFIGURE_FLAGS="--enable-compiler-warnings=error" python setup.py test -K

CONTRIBUTING.rst

@@ -18,6 +18,13 @@ instructions <README.rst#from-source>`_, then run:
     $ CONFIGURE_FLAGS="--enable-compiler-warnings=error" python3 setup.py build_ext -i
     $ python3 -m drgn --help
 
+Drgn can build, run, and pass its test suite on Python 3.6 or later. However,
+many of the tools used as part of the development workflow do not support Python
+versions once they have reached their end-of-life. Thus, your main drgn
+development environment should use a Python version which is actively supported
+upstream. In particular, the drgn development workflow no longer supported on
+Python 3.6.
+
 Testing
 -------
 
@@ -67,6 +74,9 @@ Or you can run them manually:
 
     $ pre-commit run --all-files
 
+Please remember that these pre-commit hooks do not support Python 3.6; they
+require a Python major version which is actively supported upstream.
+
 Coding Guidelines
 -----------------
 

docs/support_matrix.rst

@@ -70,7 +70,7 @@ currently fully supported are:
 
 .. Keep this in sync with vmtest/config.py.
 
-- 6.0-6.6
+- 6.0-6.7
 - 5.10-5.19
 - 5.4
 - 4.19

drgn/cli.py

@@ -240,7 +240,7 @@ def _main() -> None:
         try:
             script_type = _identify_script(args.script[0])
         except OSError as e:
-            sys.exit(e)
+            sys.exit(str(e))
         if script_type == "core":
             sys.exit(
                 f"error: {args.script[0]} is a core dump\n"
@@ -280,7 +280,7 @@ def _main() -> None:
                 else:
                     prog.set_core_dump(open_via_sudo("/proc/kcore", os.O_RDONLY))
     except OSError as e:
-        sys.exit(e)
+        sys.exit(str(e))
     except ValueError as e:
         # E.g., "not an ELF core file"
         sys.exit(f"error: {e}")

drgn/helpers/common/format.py

@@ -232,7 +232,7 @@ def number_in_binary_units(n: SupportsFloat, precision: int = 1) -> str:
     for prefix in ("", "K", "M", "G", "T", "P", "E", "Z"):
         if abs(n) < 1024:
             break
-        n /= 1024
+        n /= 1024.0
     else:
         prefix = "Y"
     if n.is_integer():

drgn/helpers/linux/mm.py

@@ -1320,9 +1320,9 @@ def access_remote_vm(mm: Object, address: IntegerLike, size: IntegerLike) -> byt
     return _linux_helper_read_vm(mm.prog_, mm.pgd, address, size)
 
 
-def cmdline(task: Object) -> List[bytes]:
+def cmdline(task: Object) -> Optional[List[bytes]]:
     """
-    Get the list of command line arguments of a task.
+    Get the list of command line arguments of a task, or ``None`` for kernel tasks.
 
     >>> cmdline(find_task(prog, 1495216))
     [b'vim', b'drgn/helpers/linux/mm.py']
@@ -1335,14 +1335,16 @@ def cmdline(task: Object) -> List[bytes]:
     :param task: ``struct task_struct *``
     """
     mm = task.mm.read_()
+    if not mm:
+        return None
     arg_start = mm.arg_start.value_()
     arg_end = mm.arg_end.value_()
     return access_remote_vm(mm, arg_start, arg_end - arg_start).split(b"\0")[:-1]
 
 
-def environ(task: Object) -> List[bytes]:
+def environ(task: Object) -> Optional[List[bytes]]:
     """
-    Get the list of environment variables of a task.
+    Get the list of environment variables of a task, or ``None`` for kernel tasks.
 
     >>> environ(find_task(prog, 1497797))
     [b'HOME=/root', b'PATH=/usr/local/sbin:/usr/local/bin:/usr/bin', b'LOGNAME=root']
@@ -1357,6 +1359,8 @@ def environ(task: Object) -> List[bytes]:
     :param task: ``struct task_struct *``
     """
     mm = task.mm.read_()
+    if not mm:
+        return None
     env_start = mm.env_start.value_()
     env_end = mm.env_end.value_()
     return access_remote_vm(mm, env_start, env_end - env_start).split(b"\0")[:-1]

drgn/helpers/linux/net.py

@@ -67,10 +67,9 @@ def for_each_net(prog: Program) -> Iterator[Object]:
 
     :return: Iterator of ``struct net *`` objects.
     """
-    for net in list_for_each_entry(
+    return list_for_each_entry(
         "struct net", prog["net_namespace_list"].address_of_(), "list"
-    ):
-        yield net
+    )
 
 
 _CLONE_NEWNET = 0x40000000
@@ -237,10 +236,7 @@ def sk_nulls_for_each(head: Object) -> Iterator[Object]:
     :param head: ``struct hlist_nulls_head *``
     :return: Iterator of ``struct sock *`` objects.
     """
-    for sk in hlist_nulls_for_each_entry(
-        "struct sock", head, "__sk_common.skc_nulls_node"
-    ):
-        yield sk
+    return hlist_nulls_for_each_entry("struct sock", head, "__sk_common.skc_nulls_node")
 
 
 def skb_shinfo(skb: Object) -> Object:

drgn/helpers/linux/nodemask.py

@@ -42,8 +42,7 @@ def for_each_node_state(prog: Program, state: IntegerLike) -> Iterator[int]:
 
     :param state: ``enum node_states`` (e.g., ``N_NORMAL_MEMORY``)
     """
-    mask = prog["node_states"][state]
-    return for_each_node_mask(mask)
+    return for_each_node_mask(prog["node_states"][state])
 
 
 def for_each_node(prog: Program) -> Iterator[int]:

drgn/helpers/linux/user.py

@@ -64,7 +64,6 @@ def for_each_user(prog: Program) -> Iterator[Object]:
     :return: Iterator of ``struct user_struct *`` objects.
     """
     for hash_entry in prog["uidhash_table"]:
-        for user in hlist_for_each_entry(
+        yield from hlist_for_each_entry(
             "struct user_struct", hash_entry, "uidhash_node"
-        ):
-            yield user
+        )

libdrgn/kdump.c

@@ -94,6 +94,11 @@ struct drgn_error *drgn_program_set_kdump(struct drgn_program *prog)
 	}
 
 	ks = kdump_set_number_attr(ctx, KDUMP_ATTR_FILE_FD, prog->core_fd);
+	if (ks == KDUMP_ERR_NOTIMPL) {
+		err = drgn_error_format(DRGN_ERROR_INVALID_ARGUMENT,
+					"%s", kdump_get_err(ctx));
+		goto err;
+	}
 	if (ks != KDUMP_OK) {
 		err = drgn_error_format(DRGN_ERROR_OTHER,
 					"kdump_set_number_attr(KDUMP_ATTR_FILE_FD): %s",

libdrgn/program.c

@@ -24,6 +24,7 @@
 #include "helpers.h"
 #include "io.h"
 #include "language.h"
+#include "log.h"
 #include "linux_kernel.h"
 #include "memory_reader.h"
 #include "minmax.h"
@@ -215,23 +216,24 @@ drgn_program_check_initialized(struct drgn_program *prog)
 	return NULL;
 }
 
-static struct drgn_error *has_kdump_signature(const char *path, int fd,
-					      bool *ret)
+static struct drgn_error *
+has_kdump_signature(struct drgn_program *prog, const char *path, bool *ret)
 {
 	char signature[max_iconst(KDUMP_SIG_LEN, FLATTENED_SIG_LEN)];
-	ssize_t r = pread_all(fd, signature, sizeof(signature), 0);
+	ssize_t r = pread_all(prog->core_fd, signature, sizeof(signature), 0);
 	if (r < 0)
 		return drgn_error_create_os("pread", errno, path);
+	*ret = false;
 	if (r >= FLATTENED_SIG_LEN
 	    && memcmp(signature, FLATTENED_SIGNATURE, FLATTENED_SIG_LEN) == 0) {
-		return drgn_error_create(DRGN_ERROR_INVALID_ARGUMENT,
-					 "the given file is in the makedumpfile flattened "
-					 "format, which drgn does not support; use "
-					 "'makedumpfile -R newfile <oldfile' to reassemble "
-					 "the file into a format drgn can read");
-	}
-	*ret = (r >= KDUMP_SIG_LEN
-	        && memcmp(signature, KDUMP_SIGNATURE, KDUMP_SIG_LEN) == 0);
+		drgn_log_warning(prog,
+				 "the given file is in the makedumpfile flattened "
+				 "format; if open fails or is too slow, reassemble "
+				 "it with 'makedumpfile -R newfile <oldfile'");
+		*ret = true;
+	} else if (r >= KDUMP_SIG_LEN
+		   && memcmp(signature, KDUMP_SIGNATURE, KDUMP_SIG_LEN) == 0)
+		*ret = true;
 	return NULL;
 }
 
@@ -252,7 +254,7 @@ drgn_program_set_core_dump_fd_internal(struct drgn_program *prog, int fd,
 	bool have_nt_taskstruct = false, is_proc_kcore;
 
 	prog->core_fd = fd;
-	err = has_kdump_signature(path, prog->core_fd, &is_kdump);
+	err = has_kdump_signature(prog, path, &is_kdump);
 	if (err)
 		goto out_fd;
 	if (is_kdump) {

tests/linux_kernel/helpers/test_mm.py

@@ -343,13 +343,19 @@ def test_cmdline(self):
         task = find_task(self.prog, os.getpid())
         self.assertEqual(cmdline(task), proc_cmdline)
 
+    def test_cmdline_kernel_thread(self):
+        self.assertIsNone(cmdline(find_task(self.prog, 2)))
+
     @skip_unless_have_full_mm_support
     def test_environ(self):
         with open("/proc/self/environ", "rb") as f:
             proc_environ = f.read().split(b"\0")[:-1]
         task = find_task(self.prog, os.getpid())
         self.assertEqual(environ(task), proc_environ)
 
+    def test_environ_kernel_thread(self):
+        self.assertIsNone(environ(find_task(self.prog, 2)))
+
     def test_for_each_vma(self):
         with fork_and_sigwait() as pid:
             self.assertEqual(

vmtest/config.py

@@ -13,6 +13,7 @@
 # Kernel versions that we run tests on and therefore support. Keep this in sync
 # with docs/support_matrix.rst.
 SUPPORTED_KERNEL_VERSIONS = (
+    "6.7",
     "6.6",
     "6.5",
     "6.4",