Merge branch 'refs/heads/upstream-HEAD' into repo-HEAD

docs/release_highlights.rst

@@ -6,6 +6,7 @@ from the full `release notes <https://github.com/osandov/drgn/releases>`_.
 
 .. toctree::
 
+   release_highlights/0.0.30.rst
    release_highlights/0.0.28.rst
    release_highlights/0.0.27.rst
    release_highlights/0.0.26.rst

docs/release_highlights/0.0.30.rst

@@ -0,0 +1,41 @@
+0.0.30 (Released December 18th, 2024)
+=====================================
+
+These are some of the highlights of drgn 0.0.30. See the `GitHub release
+<https://github.com/osandov/drgn/releases/tag/v0.0.30>`_ for the full release
+notes, including more improvements and bug fixes.
+
+This release is relatively small, as most development effort has been focused
+on the upcoming `module API <https://github.com/osandov/drgn/issues/332>`_,
+which is expected to land in the next release.
+
+Symbol Index and Kallsyms
+-------------------------
+
+Stephen Brennan continued his efforts towards `making it possible to debug the
+Linux kernel without full DWARF debugging information
+<https://github.com/osandov/drgn/issues/176>`_. The next step in this release
+was adding new helpers for looking up symbols from kallsyms:
+:func:`~drgn.helpers.linux.kallsyms.load_vmlinux_kallsyms()` and
+:func:`~drgn.helpers.linux.kallsyms.load_module_kallsyms()`. These are built on
+top of a new, generic API for fast symbol lookups: :class:`drgn.SymbolIndex`.
+
+New Python 3.13 REPL
+--------------------
+
+Python 3.13 `added
+<https://docs.python.org/3/whatsnew/3.13.html#a-better-interactive-interpreter>`_
+a vastly improved REPL with multiline editing, colorized output, interactive
+help, and more. drgn now makes use of this REPL when it is available.
+
+Stack Tracing Through Interrupt Handlers
+----------------------------------------
+
+drgn had a longstanding `bug <https://github.com/osandov/drgn/issues/304>`_
+where stack traces would stop at an interrupt handler frame. This release fixes
+that (as long as the kernel is configured to use the ORC unwinder).
+
+Linux 6.13 Support
+------------------
+
+No drgn changes were required to support Linux 6.13 as of rc3.

libdrgn/arch_x86_64.c

@@ -607,15 +607,13 @@ linux_kernel_pgtable_iterator_next_x86_64(struct drgn_program *prog,
 	for (;; level--) {
 		uint64_t table;
 		bool table_physical;
-		if (level == levels && prog->vmcoreinfo.phys_base &&
+		if (level == levels && prog->vmcoreinfo.have_phys_base &&
 		    it->it.pgtable == prog->vmcoreinfo.swapper_pg_dir) {
-			// Avoid recursive address translation on swapper_pg_dir by
-			// directly resolving to a physical address. Don't do
-			// this if phys_base is 0, since that likely means it
-			// was not present in the vmcoreinfo. It has been
-			// present since Linux kernel commit 401721ecd1dc
-			// ("kexec: export the value of phys_base instead of
-			// symbol address") (in v4.10).
+			// Avoid recursive address translation on swapper_pg_dir
+			// by directly resolving to a physical address.
+			// phys_base has been present since Linux kernel commit
+			// 401721ecd1dc ("kexec: export the value of phys_base
+			// instead of symbol address") (in v4.10).
 			table = it->it.pgtable + prog->vmcoreinfo.phys_base - START_KERNEL_MAP;
 			table_physical = true;
 		} else if (level == levels) {

libdrgn/configure.ac

@@ -1,7 +1,7 @@
 dnl Copyright (c) Meta Platforms, Inc. and affiliates.
 dnl SPDX-License-Identifier: LGPL-2.1-or-later
 
-AC_INIT([libdrgn], [0.0.29],
+AC_INIT([libdrgn], [0.0.30],
 	[https://github.com/osandov/drgn/issues],,
 	[https://github.com/osandov/drgn])
 

libdrgn/drgn.h

@@ -44,7 +44,7 @@
 /** Minor version of drgn. */
 #define DRGN_VERSION_MINOR 0
 /** Patch level of drgn. */
-#define DRGN_VERSION_PATCH 29
+#define DRGN_VERSION_PATCH 30
 
 /**
  * @defgroup ErrorHandling Error handling

libdrgn/drgn_program_parse_vmcoreinfo.inc.strswitch

@@ -89,6 +89,7 @@ struct drgn_error *drgn_program_parse_vmcoreinfo(struct drgn_program *prog,
 						   &prog->vmcoreinfo.phys_base);
 			if (err)
 				return err;
+			prog->vmcoreinfo.have_phys_base = true;
 			break;
 		}
 		@case "NUMBER(KERNELPACMASK)"@

libdrgn/error.h

@@ -155,6 +155,24 @@ static inline void drgn_recursion_guard_cleanup(int **guard)
 	__attribute__((__cleanup__(drgn_recursion_guard_cleanup), __unused__))	\
 	int *PP_UNIQUE(recursion_count_ptr) = &unique_recursion_count
 
+/**
+ * Catch a certain kind of @ref drgn_error and free it
+ *
+ * If @a errp points to a non-@c NULL error whose code matches @a code, then the
+ * free the error (if necessary), replace the pointer value with @c NULL, and
+ * return @c true. Otherwise, return @c false, and @a err is not modified.
+ */
+static inline bool drgn_error_catch(struct drgn_error **errp,
+				    enum drgn_error_code code)
+{
+	if (*errp && (*errp)->code == code) {
+		drgn_error_destroy(*errp);
+		*errp = NULL;
+		return true;
+	}
+	return false;
+}
+
 /** @} */
 
 #endif /* DRGN_ERROR_H */

libdrgn/linux_kernel_helpers.c

@@ -95,10 +95,9 @@ struct drgn_error *linux_helper_direct_mapping_offset(struct drgn_program *prog,
 	uint64_t virt_addr;
 	if (!err) {
 		err = drgn_object_read_unsigned(&tmp, &virt_addr);
-	} else if (err->code == DRGN_ERROR_LOOKUP) {
+	} else if (drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		// Avoid a confusing error message with our arbitrary variable
 		// name.
-		drgn_error_destroy(err);
 		err = drgn_error_create(DRGN_ERROR_OTHER,
 					"could not find variable in direct mapping");
 	}
@@ -248,8 +247,7 @@ struct drgn_error *linux_helper_per_cpu_ptr(struct drgn_object *res,
 						drgn_object_qualified_type(ptr),
 						ptr_value + per_cpu_offset.uvalue,
 						0);
-	} else if (err->code == DRGN_ERROR_LOOKUP) {
-		drgn_error_destroy(err);
+	} else if (drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		return drgn_object_copy(res, ptr);
 	} else {
 		return err;
@@ -299,9 +297,8 @@ struct drgn_error *linux_helper_task_thread_info(struct drgn_object *res,
 	if (!err) {
 		// CONFIG_THREAD_INFO_IN_TASK=y
 		return drgn_object_address_of(res, &tmp);
-	} else if (err->code == DRGN_ERROR_LOOKUP) {
+	} else if (drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		// CONFIG_THREAD_INFO_IN_TASK=n
-		drgn_error_destroy(err);
 		err = drgn_object_member_dereference(&tmp, task, "stack");
 		if (err)
 			return err;
@@ -340,20 +337,17 @@ struct drgn_error *linux_helper_task_cpu(const struct drgn_object *task,
 	if (err)
 		return err;
 	err = drgn_object_member_dereference(&tmp, &tmp, "cpu");
-	if (err && err->code == DRGN_ERROR_LOOKUP) {
-		drgn_error_destroy(err);
+	if (drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		err = drgn_object_member_dereference(&tmp, task, "cpu");
 	}
 	if (!err) {
 		union drgn_value value;
 		err = drgn_object_read_integer(&tmp, &value);
 		if (!err)
 			*ret = value.uvalue;
-	} else if (err->code == DRGN_ERROR_LOOKUP) {
+	} else if (drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		// CONFIG_SMP=n
-		drgn_error_destroy(err);
 		*ret = 0;
-		err = NULL;
 	}
 	return err;
 }
@@ -387,8 +381,7 @@ linux_helper_xa_load(struct drgn_object *res,
 			return err;
 		internal_flag = 2;
 		node_min = 4097;
-	} else if (err->code == DRGN_ERROR_LOOKUP) {
-		drgn_error_destroy(err);
+	} else if (drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		// entry = (void *)xa->rnode
 		err = drgn_object_member_dereference(&entry, xa, "rnode");
 		if (err)
@@ -587,10 +580,8 @@ struct drgn_error *linux_helper_idr_find(struct drgn_object *res,
 		if (err)
 			return err;
 		id -= idr_base.uvalue;
-	} else if (err->code == DRGN_ERROR_LOOKUP) {
+	} else if (!drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		/* idr_base was added in v4.16. */
-		drgn_error_destroy(err);
-	} else {
 		return err;
 	}
 
@@ -787,8 +778,7 @@ struct drgn_error *linux_helper_find_pid(struct drgn_object *res,
 		if (err)
 			return err;
 		return drgn_object_cast(res, qualified_type, &tmp);
-	} else if (err->code == DRGN_ERROR_LOOKUP) {
-		drgn_error_destroy(err);
+	} else if (drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		err = drgn_program_find_object(drgn_object_program(res),
 					       "pid_hash", NULL,
 					       DRGN_FIND_OBJECT_ANY, &tmp);
@@ -851,8 +841,7 @@ struct drgn_error *linux_helper_pid_task(struct drgn_object *res,
 		    + 1];
 	snprintf(member, sizeof(member), PID_LINKS_FORMAT, pid_type);
 	err = drgn_object_container_of(res, &first, task_struct_type, member);
-	if (err && err->code == DRGN_ERROR_LOOKUP) {
-		drgn_error_destroy(err);
+	if (drgn_error_catch(&err, DRGN_ERROR_LOOKUP)) {
 		/* container_of(first, struct task_struct, pids[pid_type].node) */
 		snprintf(member, sizeof(member), PIDS_NODE_FORMAT, pid_type);
 #undef PID_LINKS_FORMAT

libdrgn/program.h

@@ -191,6 +191,8 @@ struct drgn_program {
 				bool arm_lpae;
 				/** Whether `CRASHTIME` was in the VMCOREINFO. */
 				bool have_crashtime;
+				/** Whether `phys_base` was in the VMCOREINFO. */
+				bool have_phys_base;
 				/**
 				 * `PAGE_SHIFT` of the kernel (derived from
 				 * `PAGE_SIZE`).

scripts/build_manylinux_in_docker.sh

@@ -33,7 +33,7 @@ fi
 
 # Install a recent version of elfutils instead of whatever is in the manylinux
 # image.
-elfutils_version=0.191
+elfutils_version=0.192
 elfutils_url=https://sourceware.org/elfutils/ftp/$elfutils_version/elfutils-$elfutils_version.tar.bz2
 mkdir /tmp/elfutils
 cd /tmp/elfutils

tests/linux_kernel/helpers/test_kallsyms.py

@@ -54,15 +54,24 @@ def compare_local_symbols(self, finder, modules=False):
 
 
 class TestProcKallsyms(TestCase):
-    def test_local_proc_kallsyms(self):
-        finder = _load_proc_kallsyms()
-        compare_local_symbols(self, finder)
+    def test_static_data(self):
+        with tempfile.NamedTemporaryFile() as f:
+            f.write(KALLSYMS_DATA)
+            f.flush()
+            finder = _load_proc_kallsyms(filename=f.name)
 
-    def test_local_proc_kallsyms_with_modules(self):
-        finder = _load_proc_kallsyms(modules=True)
-        compare_local_symbols(self, finder, modules=True)
+        syms = finder(None, None, None, False)
+        expected = [
+            Symbol("null", 0x0, 8, SymbolBinding.UNIQUE, SymbolKind.UNKNOWN),
+            Symbol("local_data", 0x8, 8, SymbolBinding.UNKNOWN, SymbolKind.OBJECT),
+            Symbol("global_bss", 0x10, 16, SymbolBinding.GLOBAL, SymbolKind.OBJECT),
+            Symbol("weak_symbol", 0x20, 32, SymbolBinding.WEAK, SymbolKind.OBJECT),
+            # this one has zero size since it is at the end of vmlinux
+            Symbol("unknown", 0x40, 0, SymbolBinding.UNKNOWN, SymbolKind.UNKNOWN),
+        ]
+        self.assertEqual(syms, expected)
 
-    def test_static_data(self):
+    def test_static_data_with_modules(self):
         with tempfile.NamedTemporaryFile() as f:
             f.write(KALLSYMS_DATA)
             f.flush()