Store coroutine_env_offset in patch header

scripts/pkgbuild

@@ -340,9 +340,13 @@ kp_build() {
 kp_gen_kpatch() {
 	echo "  generating kpatches"
 
-	pushd $HOME/root.patched
+	if test -n $KP_PATCHED_BINARIES; then
+		targets=$KP_PATCHED_BINARIES
+	else
+		pushd $HOME/root.patched
 		targets=$(find . -perm /0111 -type f)
-	popd
+		popd
+	fi
 
 	rm -rf $HOME/${KP_PROJECT_PATCH%.*}
 	mkdir $HOME/${KP_PROJECT_PATCH%.*}
@@ -365,14 +369,20 @@ kp_gen_kpatch() {
 
 		eu-unstrip "$HOME/root.original/$t" "$debug"
 
+		local coroutine_arg=""
+		if test -n "$COROUTINE_ENV_OFFSET"; then
+			coroutine_arg="-c $COROUTINE_ENV_OFFSET"
+		fi
+
 		$KPATCH_PATH/kpatch_strip --strip $patched $patched.kpstripped
 		cp $patched.kpstripped $patched.relfixup
 		$KPATCH_PATH/kpatch_strip --rel-fixup $debug $patched.relfixup
 		cp $patched.relfixup $patched.stripped
 		/usr/bin/strip --strip-unneeded $patched.stripped
 		cp $patched.stripped $patched.undolink
 		$KPATCH_PATH/kpatch_strip --undo-link $debug $patched.undolink
-		$KPATCH_PATH/kpatch_make -b "$buildid" $patched.undolink -o $patched.kpatch
+		$KPATCH_PATH/kpatch_make -b "$buildid" $coroutine_arg \
+						$patched.undolink -o $patched.kpatch
 		cp $patched.kpatch $HOME/${KP_PROJECT_PATCH%.*}/$buildid.kpatch
 		no_patches=0
 	done
@@ -447,6 +457,10 @@ kp_patch_test() {
 	exit 1
 }
 
+kp_calc_coroutine_env_offset() {
+	unset COROUTINE_ENV_OFFSET
+}
+
 main() {
 	echo "Starting at "`date +%T`"..."
 
@@ -469,6 +483,7 @@ main() {
 		kp_build_hook
 		kp_build
 		kp_sanity_check
+		kp_calc_coroutine_env_offset
 		kp_gen_kpatch
 		kp_pack_patch
 	elif test "$ACTION" == "test"; then

src/kpatch_coro.c

@@ -5,6 +5,7 @@
 #include <libunwind-ptrace.h>
 
 #include <sys/utsname.h>
+#include <sys/mman.h>
 
 #include <asm/prctl.h>
 
@@ -115,8 +116,6 @@ kpatch_coro_free(struct kpatch_coro *c)
 #define STACK_OFFSET_COROUTINE_UCONTEXT (7 * sizeof(long))
 #define STACK_OFFSET_COROUTINE (8 * sizeof(long))
 
-#define UCONTEXT_OFFSET_JMPBUF 0x38
-
 #define UCONTEXT_OFFSET_UC_STACK_SS_SP		offsetof(ucontext_t, uc_stack.ss_sp)
 #define UCONTEXT_OFFSET_UC_STACK_SS_SIZE	offsetof(ucontext_t, uc_stack.ss_size)
 
@@ -235,60 +234,40 @@ int is_centos7_qemu(struct kpatch_process *proc)
 	return 1;
 };
 
-
-static int qemu_centos7_find_coroutines(struct kpatch_process *proc)
+static int get_patch_coroutine_env_offset(struct kpatch_process *proc)
 {
-	struct object_file *oheap, *tcmalloc;
-	struct process_mem_iter *iter;
-	struct kpatch_coro *coro;
-	struct vm_area heap;
-	unsigned long __start_context, ptr_guard, cur;
-	int ret;
-
-	if (!is_test_target(proc, "fail_coro") && !is_centos7_qemu(proc))
-		return CORO_SEARCH_NEXT;
-
-	kpdebug("Looking for coroutines in QEMU %d...\n", proc->pid);
-	oheap = kpatch_process_get_obj_by_regex(proc, "^\\[heap\\]$");
-	tcmalloc = kpatch_process_get_obj_by_regex(proc, "^libtcmalloc.*\\.so\\.4.*");
-	if (!oheap) {
-		kpdebug("FAIL. Can't find [heap](%p)\n", oheap);
-		return -1;
-	}
+	struct object_file *o;
+	list_for_each_entry(o, &proc->objs, list) {
+		if (!o->name || strcmp(proc->comm, o->name))
+			continue;
 
-	/* NOTE(pboldin) We accurately craft stack for test so we
-	 * don't need tcmalloc installed and used
-	 */
-	if (!tcmalloc && !is_test_target(proc, "fail_coro")) {
-		kpdebug("FAIL. Can't find tcmalloc lib. Full [heap] scan is not "
-			"implemented yet");
-		return -1;
-	}
-	heap = list_first_entry(&oheap->vma, struct obj_vm_area, list)->inmem;
+		if (o->kpfile.patch)
+			return o->kpfile.patch->coroutine_env_offset;
 
-	ret = locate_start_context_symbol(proc, &__start_context);
-	if (ret < 0) {
-		kpdebug("FAIL. Can't locate_start_context_symbol\n");
-		return CORO_SEARCH_NEXT;
+		if (o->skpfile && o->skpfile->patch)
+			return o->skpfile->patch->coroutine_env_offset;
 	}
+	return 0;
+}
 
-	ret = get_ptr_guard(proc, &ptr_guard);
-	if (ret < 0) {
-		kpdebug("FAIL. Can't get_ptr_guard\n");
-		return -1;
-	}
+static int qemu_centos7_find_coroutines_vma(struct kpatch_process *proc, struct vm_area vma,
+	unsigned long __start_context, unsigned long ptr_guard, int patch_coroutine_env_offset)
+{
+	int ret;
+	struct process_mem_iter *iter;
+	unsigned long cur;
+	struct kpatch_coro *coro;
 
 	iter = kpatch_process_mem_iter_init(proc);
 	if (iter == NULL) {
 		kpdebug("FAIL. Can't allocate process memory iterator.\n");
 		return -1;
 	}
 
-	for (cur = heap.start; cur < heap.end; cur += PAGE_SIZE) {
+	for (cur = vma.start; cur < vma.end; cur += PAGE_SIZE) {
 		unsigned long val, val2;
 		unsigned long ptr = cur + PAGE_SIZE;
 		unsigned long *regs;
-
 		val = PEEK_ULONG(ptr - STACK_OFFSET_START_CONTEXT);
 		if (val != __start_context)
 			continue;
@@ -308,7 +287,7 @@ static int qemu_centos7_find_coroutines(struct kpatch_process *proc)
 			break;
 		}
 		ret = kpatch_process_mem_read(proc,
-					      val + UCONTEXT_OFFSET_JMPBUF,
+					      val + patch_coroutine_env_offset,
 					      &coro->env,
 					      sizeof(coro->env));
 		if (ret < 0) {
@@ -321,8 +300,66 @@ static int qemu_centos7_find_coroutines(struct kpatch_process *proc)
 		regs[JB_RSP] = PTR_DEMANGLE(regs[JB_RSP], ptr_guard);
 		regs[JB_RIP] = PTR_DEMANGLE(regs[JB_RIP], ptr_guard);
 	}
-
 	kpatch_process_mem_iter_free(iter);
+	return ret;
+}
+
+static int qemu_centos7_find_coroutines(struct kpatch_process *proc)
+{
+	struct object_file *oanonymous, *oheap, *tcmalloc;
+	struct obj_vm_area *ovma;
+	struct vm_area heap;
+	unsigned long __start_context, ptr_guard;
+	int patch_coroutine_env_offset ;
+	int ret;
+
+	if (!is_test_target(proc, "fail_coro") && !is_centos7_qemu(proc))
+		return CORO_SEARCH_NEXT;
+
+	kpdebug("Looking for coroutines in QEMU %d...\n", proc->pid);
+	tcmalloc = kpatch_process_get_obj_by_regex(proc, "^libtcmalloc.*\\.so\\.4.*");
+
+	/* NOTE(pboldin) We accurately craft stack for test so we
+	 * don't need tcmalloc installed and used
+	 */
+	if (!tcmalloc && !is_test_target(proc, "fail_coro")) {
+		kpdebug("FAIL. Can't find tcmalloc lib. Full [heap] scan is not "
+			"implemented yet");
+		return -1;
+	}
+
+	ret = get_ptr_guard(proc, &ptr_guard);
+	if (ret < 0) {
+		kpdebug("FAIL. Can't get_ptr_guard\n");
+		return -1;
+	}
+
+	ret = locate_start_context_symbol(proc, &__start_context);
+	if (ret < 0) {
+		kpdebug("FAIL. Can't locate_start_context_symbol\n");
+		return CORO_SEARCH_NEXT;
+	}
+
+	patch_coroutine_env_offset = get_patch_coroutine_env_offset(proc);
+	if (patch_coroutine_env_offset <= 0) {
+		kpdebug("FAIL. No patch_coroutine_env_offset\n");
+		return patch_coroutine_env_offset;
+	}
+
+	oheap = kpatch_process_get_obj_by_regex(proc, "^\\[heap\\]$");
+	if (!oheap) {
+		kpdebug("FAIL. Can't find [heap](%p)\n", oheap);
+		return -1;
+	}
+	heap = list_first_entry(&oheap->vma, struct obj_vm_area, list)->inmem;
+	qemu_centos7_find_coroutines_vma(proc, heap, __start_context, ptr_guard, patch_coroutine_env_offset);
+
+	oanonymous = kpatch_process_get_obj_by_regex(proc, "\\[anonymous\\]$");
+	list_for_each_entry(ovma, &oanonymous->vma, list) {
+		if (!(ovma->inmem.prot & (PROT_READ|PROT_WRITE)))
+			continue;
+		qemu_centos7_find_coroutines_vma(proc, ovma->inmem, __start_context, ptr_guard, patch_coroutine_env_offset);
+	}
 
 	return ret;
 }

src/kpatch_file.h

@@ -152,7 +152,8 @@ struct kpatch_file {
 	};
 
 	char srcversion[25]; /* srcversion of module or zeros */
-	char pad2[231];
+	uint32_t coroutine_env_offset;
+	char pad2[227];
 
 	/* relocations */
 	/* content */

src/kpatch_make.c

@@ -26,7 +26,7 @@ static void xerror(const char *fmt, ...)
 	exit(1);
 }
 
-int make_file(int fdo, void *buf1, off_t size, const char *buildid)
+int make_file(int fdo, void *buf1, off_t size, const char *buildid, int coroutine_env_offset)
 {
 	int res;
 	struct kpatch_file khdr;
@@ -44,6 +44,8 @@ int make_file(int fdo, void *buf1, off_t size, const char *buildid)
 	size = ALIGN(size, 16);
 	khdr.total_size = khdr.kpatch_offset + size;
 
+	khdr.coroutine_env_offset = coroutine_env_offset;
+
 	res = write(fdo, &khdr, sizeof(khdr));
 	res += write(fdo, buf1, size);
 
@@ -57,6 +59,7 @@ static void usage(void)
 {
 	printf("Usage: kpatch_make [-d] -n <modulename> [-v <version>] -e <entryaddr> [-o <output>] <input1> [input2]\n");
 	printf("   -b buildid = target buildid for patch\n");
+	printf("   -c offset = env offset in coroutine\n");
 	printf("   -d debug (verbose)\n");
 	printf("\n");
 	printf("   result is printed to output and is the following:\n");
@@ -72,8 +75,9 @@ int main(int argc, char **argv)
 	void *buf;
 	struct stat st;
 	char *buildid = NULL, *outputname = NULL;
+	int coroutine_env_offset = -1;
 
-	while ((opt = getopt(argc, argv, "db:o:v:s:")) != -1) {
+	while ((opt = getopt(argc, argv, "db:o:v:s:c:")) != -1) {
 		switch (opt) {
 		case 'd':
 			verbose = 1;
@@ -84,6 +88,12 @@ int main(int argc, char **argv)
 		case 'o':
 			outputname = strdup(optarg);
 			break;
+		case 'c':
+			if (sscanf(optarg, "%d", &coroutine_env_offset) != 1) {
+				printf("Error: can't parse jmpbuf offset for coroutines.\n");
+				usage();
+			}
+			break;
 		default: /* '?' */
 			usage();
 		}
@@ -109,5 +119,5 @@ int main(int argc, char **argv)
 			xerror("Can't open output file '%s'", outputname);
 	}
 
-	return make_file(fdo, buf, st.st_size, buildid);
+	return make_file(fdo, buf, st.st_size, buildid, coroutine_env_offset);
 }