[glibc/release/2.36/master] hppa: Fix initialization of dp register [BZ 29635]

[glibc/release/2.36/master] hppa: Fix initialization of dp register [BZ 29635]

[John David Anglin]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=d1d8379bff34f02f86f82db2cef5bf66746d3560

commit d1d8379bff34f02f86f82db2cef5bf66746d3560
Author: John David Anglin <danglin@gcc.gnu.org>
Date:   Sat Oct 1 19:49:25 2022 +0000

    hppa: Fix initialization of dp register [BZ 29635]
    
    After upgrading glibc to Debian 2.35-1, gdb faulted on
    startup and dropped core in a function call in the main
    application.  This was caused by not initializing the
    global dp register for the main application early enough.
    
    Restore the code to initialize dp in _dl_start_user.
    It was removed when code was added to initialize dp in
    elf_machine_runtime_setup.
    
    Signed-off-by: John David Anglin <dave.anglin@bell.net>

Diff:
---
 sysdeps/hppa/dl-machine.h | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/sysdeps/hppa/dl-machine.h b/sysdeps/hppa/dl-machine.h
index c865713be1..1d51948566 100644
--- a/sysdeps/hppa/dl-machine.h
+++ b/sysdeps/hppa/dl-machine.h
@@ -347,6 +347,16 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
    its return value is the user program's entry point.  */
 
 #define RTLD_START \
+/* Set up dp for any non-PIC lib constructors that may be called.  */	\
+static struct link_map * __attribute__((used))				\
+set_dp (struct link_map *map)						\
+{									\
+  register Elf32_Addr dp asm ("%r27");					\
+  dp = D_PTR (map, l_info[DT_PLTGOT]);					\
+  asm volatile ("" : : "r" (dp));					\
+  return map;								\
+}									\
+									\
 asm (									\
 "	.text\n"							\
 "	.globl _start\n"						\
@@ -426,6 +436,13 @@ asm (									\
 	   direct loader invocation.  Thus, argc and argv must be	\
 	   reloaded from from _dl_argc and _dl_argv.  */		\
 									\
+	/* Load main_map from _rtld_local and setup dp. */		\
+"	addil	LT'_rtld_local,%r19\n"					\
+"	ldw	RT'_rtld_local(%r1),%r26\n"				\
+"	bl	set_dp, %r2\n"						\
+"	ldw	0(%r26),%r26\n"						\
+"	copy	%ret0,%r26\n"						\
+									\
 	/* Load argc from _dl_argc.  */					\
 "	addil	LT'_dl_argc,%r19\n"					\
 "	ldw	RT'_dl_argc(%r1),%r20\n"				\
@@ -438,13 +455,10 @@ asm (									\
 "	ldw	0(%r20),%r24\n"						\
 "	stw	%r24,-44(%sp)\n"					\
 									\
-	/* Call _dl_init(main_map, argc, argv, envp). */		\
-"	addil	LT'_rtld_local,%r19\n"					\
-"	ldw	RT'_rtld_local(%r1),%r26\n"				\
-"	ldw	0(%r26),%r26\n"						\
-									\
 	/* envp = argv + argc + 1 */					\
 "	sh2add	%r25,%r24,%r23\n"					\
+									\
+	/* Call _dl_init(main_map, argc, argv, envp). */		\
 "	bl	_dl_init,%r2\n"						\
 "	ldo	4(%r23),%r23\n"	/* delay slot */			\
 									\