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From: Alan Modra <amodra@gmail.com>
To: libc-alpha@sourceware.org
Cc: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Subject: [PATCH 3/5] [PowerPC] Relocate stinfo->main
Date: Mon, 24 Jan 2022 14:20:52 +1030	[thread overview]
Message-ID: <Ye4iHPb/sTm517LH@squeak.grove.modra.org> (raw)
In-Reply-To: <Ye1NJQwEpe7AyNYD@squeak.grove.modra.org>

The previous 2 patches got us to the point of segfaulting when trying
to transfer to main.

start_addresses in sysdeps/powerpc/powerpc64/start.S is historical
baggage that should disappear.  Until someone does that, relocating
stinfo->main by hand is one solution to the fact that the field may be
unrelocated at the time it is accessed.  This is similar to what is
done for dynamic tags via the D_PTR macro.  The makefile change is
needed to pick up elf/dl-static-tls.h from dl-machine.h.

diff --git a/sysdeps/unix/sysv/linux/powerpc/Makefile b/sysdeps/unix/sysv/linux/powerpc/Makefile
index fc7c29c695..93783cae00 100644
--- a/sysdeps/unix/sysv/linux/powerpc/Makefile
+++ b/sysdeps/unix/sysv/linux/powerpc/Makefile
@@ -27,3 +27,9 @@ tests += $(tests-static)
 tests += test-gettimebasefreq
 tests += test-powerpc-linux-sysconf
 endif
+
+ifeq ($(subdir),csu)
+# to relocate stinfo->main
+CPPFLAGS-libc-start.o += -I../elf
+CPPFLAGS-libc-start.op += -I../elf
+endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-start.c b/sysdeps/unix/sysv/linux/powerpc/libc-start.c
index bb97d16145..8f0d3a0eac 100644
--- a/sysdeps/unix/sysv/linux/powerpc/libc-start.c
+++ b/sysdeps/unix/sysv/linux/powerpc/libc-start.c
@@ -23,6 +23,10 @@
 #ifndef SHARED
 #include <hwcapinfo.h>
 #endif
+#if ENABLE_STATIC_PIE && !defined SHARED
+/* For elf_machine_load_address.  */
+#include <dl-machine.h>
+#endif
 
 /* The main work is done in the generic function.  */
 #define LIBC_START_MAIN generic_start_main
@@ -95,8 +99,15 @@ __libc_start_main_impl (int argc, char **argv,
   __tcb_parse_hwcap_and_convert_at_platform ();
 #endif
 
-  return generic_start_main (stinfo->main, argc, argv, auxvec,
-			     stinfo->init, stinfo->fini, rtld_fini,
+  void *main = stinfo->main;
+#if ENABLE_STATIC_PIE && !defined SHARED
+  struct link_map *map = _dl_get_dl_main_map ();
+  if (!map->l_relocated)
+    main = (char *) main + elf_machine_load_address ();
+#endif
+
+  return generic_start_main (main, argc, argv, auxvec,
+			     NULL, NULL, rtld_fini,
 			     stack_on_entry);
 }
 DEFINE_LIBC_START_MAIN_VERSION

-- 
Alan Modra
Australia Development Lab, IBM

  parent reply	other threads:[~2022-01-24  3:50 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-23 12:42 [PowerPC64] Use medium model toc accesses throughout Alan Modra
2022-01-24  3:47 ` [PATCH 2/5] [PowerPC64] Set up thread register for _dl_relocate_static_pie Alan Modra
2022-02-16 23:02   ` Paul E Murphy
2022-02-19  0:49     ` Alan Modra
2022-01-24  3:50 ` Alan Modra [this message]
2022-01-24  4:48   ` [PATCH 3/5] [PowerPC] Relocate stinfo->main H.J. Lu
2022-01-24  6:51     ` Alan Modra
2022-01-24  3:52 ` [PATCH 4/5] Constify a variable in dl_vdso_vsym Alan Modra
2022-01-24  4:06 ` [PATCH 5/5] Enable static-pie on powerpc64 Alan Modra
2022-01-27 18:39   ` Florian Weimer
2022-01-28  8:45     ` Alan Modra
2022-01-28 17:48 ` [PowerPC64] Use medium model toc accesses throughout Paul E Murphy
2022-01-29  1:24   ` Alan Modra
2022-02-28  6:40 ` [PATCH v2 0/4] PowerPC64 static-pie Alan Modra
2022-02-28  6:40   ` [PATCH v2 1/4] powerpc64: Use medium model toc accesses throughout Alan Modra
2022-04-08 22:28     ` Tulio Magno Quites Machado Filho
2022-02-28  6:40   ` [PATCH v2 2/4] powerpc64: Set up thread register for _dl_relocate_static_pie Alan Modra
2022-04-08 22:28     ` Tulio Magno Quites Machado Filho
2022-02-28  6:40   ` [PATCH v2 3/4] powerpc: Relocate stinfo->main Alan Modra
2022-04-08 22:32     ` Tulio Magno Quites Machado Filho
2022-02-28  6:40   ` [PATCH v2 4/4] powerpc64: Enable static-pie Alan Modra
2022-04-08 22:49     ` Tulio Magno Quites Machado Filho
2022-04-14  1:16       ` Alan Modra
2022-04-14  3:42         ` Fangrui Song
2022-04-20  7:21         ` [PATCH v3] " Alan Modra
2022-03-04 12:48   ` [PATCH v2 0/4] PowerPC64 static-pie Alan Modra
2022-04-08  8:06     ` Alan Modra
2022-04-09  0:14       ` Fangrui Song
2022-04-14  0:33         ` Alan Modra
2022-04-14  1:54           ` DT_RELR without libc.so dependency H.J. Lu
2022-04-14  3:43             ` Fangrui Song
2022-04-14  5:18             ` Alan Modra
2022-04-14 17:55               ` H.J. Lu
2022-04-08 22:27   ` [PATCH v2 0/4] PowerPC64 static-pie Tulio Magno Quites Machado Filho
2022-04-11  1:38     ` Alan Modra

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