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* [PATCH] gdb: Don't assume r_ldsomap when r_version > 1 on Linux
@ 2021-08-17  1:15 H.J. Lu
  2021-08-17 13:09 ` Simon Marchi
  2021-08-17 13:50 ` [PATCH v2] " H.J. Lu
  0 siblings, 2 replies; 5+ messages in thread
From: H.J. Lu @ 2021-08-17  1:15 UTC (permalink / raw)
  To: GDB

glibc is planning to add a field to support multiple namespaces.  But
there will be no r_ldsomap when r_version is bumped to 2.  Add
linux_[ilp32|lp64]_fetch_link_map_offsets to set r_ldsomap_offset to -1
and use them for Linux targets.

	PR gdb/28236
	* aarch64-linux-tdep.c (aarch64_linux_init_abi): Replace
	svr4_[ilp32|lp64]_fetch_link_map_offsets with
	linux_[ilp32|lp64]_fetch_link_map_offsets.
	* alpha-linux-tdep.c (alpha_linux_init_abi): Likewise.
	* amd64-linux-tdep.c (amd64_linux_init_abi): Likewise.
	(amd64_x32_linux_init_abi): Likewise.
	* ia64-linux-tdep.c (ia64_linux_init_abi): Likewise.
	* mips-linux-tdep.c (mips_linux_init_abi): Likewise.
	* ppc-linux-tdep.c (ppc_linux_init_abi): Likewise.
	* riscv-linux-tdep.c (riscv_linux_init_abi): Likewise.
	* s390-linux-tdep.c (s390_linux_init_abi_31): Likewise.
	(s390_linux_init_abi_64): Likewise.
	* sparc64-linux-tdep.c (sparc64_linux_init_abi): Likewise.
	* tilegx-linux-tdep.c (tilegx_linux_init_abi): Likewise.
	* linux-tdep.c: Include "solib-svr4.h".
	(linux_ilp32_fetch_link_map_offsets): New.
	(linux_lp64_fetch_link_map_offsets): Likewise.
	* linux-tdep.h (linux_ilp32_fetch_link_map_offsets): New.
	(linux_lp64_fetch_link_map_offsets): Likewise.
---
 gdb/aarch64-linux-tdep.c |  2 +-
 gdb/alpha-linux-tdep.c   |  2 +-
 gdb/amd64-linux-tdep.c   |  4 +--
 gdb/ia64-linux-tdep.c    |  2 +-
 gdb/linux-tdep.c         | 60 ++++++++++++++++++++++++++++++++++++++++
 gdb/linux-tdep.h         |  5 ++++
 gdb/mips-linux-tdep.c    |  6 ++--
 gdb/ppc-linux-tdep.c     |  4 +--
 gdb/riscv-linux-tdep.c   |  4 +--
 gdb/s390-linux-tdep.c    |  4 +--
 gdb/sparc64-linux-tdep.c |  2 +-
 gdb/tilegx-linux-tdep.c  |  4 +--
 12 files changed, 82 insertions(+), 17 deletions(-)

diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
index 63c200b47f7..b1225438d9d 100644
--- a/gdb/aarch64-linux-tdep.c
+++ b/gdb/aarch64-linux-tdep.c
@@ -1795,7 +1795,7 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   linux_init_abi (info, gdbarch, 1);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_lp64_fetch_link_map_offsets);
+					 linux_lp64_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/alpha-linux-tdep.c b/gdb/alpha-linux-tdep.c
index c2cffc13c20..0a00fc1f310 100644
--- a/gdb/alpha-linux-tdep.c
+++ b/gdb/alpha-linux-tdep.c
@@ -374,7 +374,7 @@ alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_lp64_fetch_link_map_offsets);
+    (gdbarch, linux_lp64_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
index ac6843c1fdd..715add8a7b0 100644
--- a/gdb/amd64-linux-tdep.c
+++ b/gdb/amd64-linux-tdep.c
@@ -2042,7 +2042,7 @@ amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_lp64_fetch_link_map_offsets);
+    (gdbarch, linux_lp64_fetch_link_map_offsets);
 
   /* Register DTrace handlers.  */
   set_gdbarch_dtrace_parse_probe_argument (gdbarch, amd64_dtrace_parse_probe_argument);
@@ -2256,7 +2256,7 @@ amd64_x32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 }
 
 void _initialize_amd64_linux_tdep ();
diff --git a/gdb/ia64-linux-tdep.c b/gdb/ia64-linux-tdep.c
index a17ec590002..71767ddf83e 100644
--- a/gdb/ia64-linux-tdep.c
+++ b/gdb/ia64-linux-tdep.c
@@ -237,7 +237,7 @@ ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_lp64_fetch_link_map_offsets);
+    (gdbarch, linux_lp64_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index 637d3d36a0b..92ecedfd1cf 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -41,6 +41,7 @@
 #include "gdbsupport/gdb_optional.h"
 #include "gcore.h"
 #include "gcore-elf.h"
+#include "solib-svr4.h"
 
 #include <ctype.h>
 
@@ -2724,3 +2725,62 @@ more information about this file, refer to the manpage of proc(5) and core(5).")
 			   NULL, show_dump_excluded_mappings,
 			   &setlist, &showlist);
 }
+
+/* Fetch (and possibly build) an appropriate `struct link_map_offsets'
+   for ILP32/LP64 Linux systems which don't have the r_ldsomap field.  */
+
+struct link_map_offsets *
+linux_ilp32_fetch_link_map_offsets (void)
+{
+  static struct link_map_offsets lmo;
+  static struct link_map_offsets *lmp = NULL;
+
+  if (lmp == NULL)
+    {
+      lmp = &lmo;
+
+      lmo.r_version_offset = 0;
+      lmo.r_version_size = 4;
+      lmo.r_map_offset = 4;
+      lmo.r_brk_offset = 8;
+      lmo.r_ldsomap_offset = -1;
+
+      /* Everything we need is in the first 20 bytes.  */
+      lmo.link_map_size = 20;
+      lmo.l_addr_offset = 0;
+      lmo.l_name_offset = 4;
+      lmo.l_ld_offset = 8;
+      lmo.l_next_offset = 12;
+      lmo.l_prev_offset = 16;
+    }
+
+  return lmp;
+}
+
+struct link_map_offsets *
+linux_lp64_fetch_link_map_offsets (void)
+{
+  static struct link_map_offsets lmo;
+  static struct link_map_offsets *lmp = NULL;
+
+  if (lmp == NULL)
+    {
+      lmp = &lmo;
+
+      lmo.r_version_offset = 0;
+      lmo.r_version_size = 4;
+      lmo.r_map_offset = 8;
+      lmo.r_brk_offset = 16;
+      lmo.r_ldsomap_offset = -1;
+
+      /* Everything we need is in the first 40 bytes.  */
+      lmo.link_map_size = 40;
+      lmo.l_addr_offset = 0;
+      lmo.l_name_offset = 8;
+      lmo.l_ld_offset = 16;
+      lmo.l_next_offset = 24;
+      lmo.l_prev_offset = 32;
+    }
+
+  return lmp;
+}
diff --git a/gdb/linux-tdep.h b/gdb/linux-tdep.h
index 28b60e46579..26873a989d2 100644
--- a/gdb/linux-tdep.h
+++ b/gdb/linux-tdep.h
@@ -98,4 +98,9 @@ extern CORE_ADDR linux_get_hwcap (struct target_ops *target);
    error, 0 is returned.  */
 extern CORE_ADDR linux_get_hwcap2 (struct target_ops *target);
 
+/* Fetch (and possibly build) an appropriate `struct link_map_offsets'
+   for ILP32 and LP64 Linux systems.  */
+extern struct link_map_offsets *linux_ilp32_fetch_link_map_offsets (void);
+extern struct link_map_offsets *linux_lp64_fetch_link_map_offsets (void);
+
 #endif /* linux-tdep.h */
diff --git a/gdb/mips-linux-tdep.c b/gdb/mips-linux-tdep.c
index 1ceed5250fe..ce287f6a354 100644
--- a/gdb/mips-linux-tdep.c
+++ b/gdb/mips-linux-tdep.c
@@ -1542,7 +1542,7 @@ mips_linux_init_abi (struct gdbarch_info info,
 	set_gdbarch_get_longjmp_target (gdbarch,
 					mips_linux_get_longjmp_target);
 	set_solib_svr4_fetch_link_map_offsets
-	  (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+	  (gdbarch, linux_ilp32_fetch_link_map_offsets);
 	tramp_frame_prepend_unwinder (gdbarch, &micromips_linux_o32_sigframe);
 	tramp_frame_prepend_unwinder (gdbarch,
 				      &micromips_linux_o32_rt_sigframe);
@@ -1554,7 +1554,7 @@ mips_linux_init_abi (struct gdbarch_info info,
 	set_gdbarch_get_longjmp_target (gdbarch,
 					mips_linux_get_longjmp_target);
 	set_solib_svr4_fetch_link_map_offsets
-	  (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+	  (gdbarch, linux_ilp32_fetch_link_map_offsets);
 	set_gdbarch_long_double_bit (gdbarch, 128);
 	/* These floatformats should probably be renamed.  MIPS uses
 	   the same 128-bit IEEE floating point format that IA-64 uses,
@@ -1570,7 +1570,7 @@ mips_linux_init_abi (struct gdbarch_info info,
 	set_gdbarch_get_longjmp_target (gdbarch,
 					mips64_linux_get_longjmp_target);
 	set_solib_svr4_fetch_link_map_offsets
-	  (gdbarch, svr4_lp64_fetch_link_map_offsets);
+	  (gdbarch, linux_lp64_fetch_link_map_offsets);
 	set_gdbarch_long_double_bit (gdbarch, 128);
 	/* These floatformats should probably be renamed.  MIPS uses
 	   the same 128-bit IEEE floating point format that IA-64 uses,
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index 1e94922f25a..e62f45a35d8 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -2035,7 +2035,7 @@ ppc_linux_init_abi (struct gdbarch_info info,
       /* Shared library handling.  */
       set_gdbarch_skip_trampoline_code (gdbarch, ppc_skip_trampoline_code);
       set_solib_svr4_fetch_link_map_offsets
-	(gdbarch, svr4_ilp32_fetch_link_map_offsets);
+	(gdbarch, linux_ilp32_fetch_link_map_offsets);
 
       /* Setting the correct XML syscall filename.  */
       set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_PPC);
@@ -2087,7 +2087,7 @@ ppc_linux_init_abi (struct gdbarch_info info,
       /* Shared library handling.  */
       set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
       set_solib_svr4_fetch_link_map_offsets
-	(gdbarch, svr4_lp64_fetch_link_map_offsets);
+	(gdbarch, linux_lp64_fetch_link_map_offsets);
 
       /* Setting the correct XML syscall filename.  */
       set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_PPC64);
diff --git a/gdb/riscv-linux-tdep.c b/gdb/riscv-linux-tdep.c
index 49dc75bb618..7351e1901d6 100644
--- a/gdb/riscv-linux-tdep.c
+++ b/gdb/riscv-linux-tdep.c
@@ -187,8 +187,8 @@ riscv_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 					 (riscv_isa_xlen (gdbarch) == 4
-					  ? svr4_ilp32_fetch_link_map_offsets
-					  : svr4_lp64_fetch_link_map_offsets));
+					  ? linux_ilp32_fetch_link_map_offsets
+					  : linux_lp64_fetch_link_map_offsets));
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
diff --git a/gdb/s390-linux-tdep.c b/gdb/s390-linux-tdep.c
index 1f40e10e3d3..04e3fc640d2 100644
--- a/gdb/s390-linux-tdep.c
+++ b/gdb/s390-linux-tdep.c
@@ -1158,7 +1158,7 @@ s390_linux_init_abi_31 (struct gdbarch_info info, struct gdbarch *gdbarch)
   s390_linux_init_abi_any (info, gdbarch);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
   set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_S390);
 }
 
@@ -1174,7 +1174,7 @@ s390_linux_init_abi_64 (struct gdbarch_info info, struct gdbarch *gdbarch)
   s390_linux_init_abi_any (info, gdbarch);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_lp64_fetch_link_map_offsets);
+					 linux_lp64_fetch_link_map_offsets);
   set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_S390X);
 }
 
diff --git a/gdb/sparc64-linux-tdep.c b/gdb/sparc64-linux-tdep.c
index ea692ac00ef..e63fa87c69b 100644
--- a/gdb/sparc64-linux-tdep.c
+++ b/gdb/sparc64-linux-tdep.c
@@ -383,7 +383,7 @@ sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux has SVR4-style shared libraries...  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_lp64_fetch_link_map_offsets);
+    (gdbarch, linux_lp64_fetch_link_map_offsets);
 
   /* ...which means that we need some special handling when doing
      prologue analysis.  */
diff --git a/gdb/tilegx-linux-tdep.c b/gdb/tilegx-linux-tdep.c
index 382e7f6d908..353497a3434 100644
--- a/gdb/tilegx-linux-tdep.c
+++ b/gdb/tilegx-linux-tdep.c
@@ -121,10 +121,10 @@ tilegx_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux uses SVR4-style shared libraries.  */
   if (arch_size == 32)
     set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					   svr4_ilp32_fetch_link_map_offsets);
+					   linux_ilp32_fetch_link_map_offsets);
   else
     set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					   svr4_lp64_fetch_link_map_offsets);
+					   linux_lp64_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
-- 
2.31.1


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] gdb: Don't assume r_ldsomap when r_version > 1 on Linux
  2021-08-17  1:15 [PATCH] gdb: Don't assume r_ldsomap when r_version > 1 on Linux H.J. Lu
@ 2021-08-17 13:09 ` Simon Marchi
  2021-08-17 13:44   ` H.J. Lu
  2021-08-17 13:50 ` [PATCH v2] " H.J. Lu
  1 sibling, 1 reply; 5+ messages in thread
From: Simon Marchi @ 2021-08-17 13:09 UTC (permalink / raw)
  To: H.J. Lu, GDB



On 2021-08-16 9:15 p.m., H.J. Lu via Gdb-patches wrote:
> glibc is planning to add a field to support multiple namespaces.  But
> there will be no r_ldsomap when r_version is bumped to 2.  Add
> linux_[ilp32|lp64]_fetch_link_map_offsets to set r_ldsomap_offset to -1
> and use them for Linux targets.

As Carlos mentioned in the Buzilla thread, r_ldsomap is specific to
Solaris.  It would be good to mention that in the commit message,
because that helps understand the patch (and is probably not very well
known).

Just to be clear, is this new version 2 specific to Linux or glibc?  A
system using another libc won't use that layout, unless that other libc
copies what glibc does?  I'm thinking that another libc could use
version == 2, but for a different layout, in which case we would have to
have callbacks specific to each libc.  Or, is there coordination between
various libcs about how to evolve this layout?

> 	PR gdb/28236
> 	* aarch64-linux-tdep.c (aarch64_linux_init_abi): Replace
> 	svr4_[ilp32|lp64]_fetch_link_map_offsets with
> 	linux_[ilp32|lp64]_fetch_link_map_offsets.
> 	* alpha-linux-tdep.c (alpha_linux_init_abi): Likewise.
> 	* amd64-linux-tdep.c (amd64_linux_init_abi): Likewise.
> 	(amd64_x32_linux_init_abi): Likewise.
> 	* ia64-linux-tdep.c (ia64_linux_init_abi): Likewise.
> 	* mips-linux-tdep.c (mips_linux_init_abi): Likewise.
> 	* ppc-linux-tdep.c (ppc_linux_init_abi): Likewise.
> 	* riscv-linux-tdep.c (riscv_linux_init_abi): Likewise.
> 	* s390-linux-tdep.c (s390_linux_init_abi_31): Likewise.
> 	(s390_linux_init_abi_64): Likewise.
> 	* sparc64-linux-tdep.c (sparc64_linux_init_abi): Likewise.
> 	* tilegx-linux-tdep.c (tilegx_linux_init_abi): Likewise.
> 	* linux-tdep.c: Include "solib-svr4.h".
> 	(linux_ilp32_fetch_link_map_offsets): New.
> 	(linux_lp64_fetch_link_map_offsets): Likewise.
> 	* linux-tdep.h (linux_ilp32_fetch_link_map_offsets): New.
> 	(linux_lp64_fetch_link_map_offsets): Likewise.

Note that GDB doesn't use ChangeLogs anymore.  You can use

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28236

At the bottom to link to the Bugzilla entry.

> ---
>  gdb/aarch64-linux-tdep.c |  2 +-
>  gdb/alpha-linux-tdep.c   |  2 +-
>  gdb/amd64-linux-tdep.c   |  4 +--
>  gdb/ia64-linux-tdep.c    |  2 +-
>  gdb/linux-tdep.c         | 60 ++++++++++++++++++++++++++++++++++++++++
>  gdb/linux-tdep.h         |  5 ++++
>  gdb/mips-linux-tdep.c    |  6 ++--
>  gdb/ppc-linux-tdep.c     |  4 +--
>  gdb/riscv-linux-tdep.c   |  4 +--
>  gdb/s390-linux-tdep.c    |  4 +--
>  gdb/sparc64-linux-tdep.c |  2 +-
>  gdb/tilegx-linux-tdep.c  |  4 +--

I don't understand why some *-linux-tdep.c are changed but not all.  Do
the following files need to be changed too?

 - arc-linux-tdep.c
 - arm-linux-tdep.c
 - cris-linux-tdep.c
 - csky-linux-tdep.c
 - i386-linux-tdep.c
 - m32r-linux-tdep.c
 - m68k-linux-tdep.c
 - microblaze-linux-tdep.c
 - mn10300-linux-tdep.c
 - nios2-linux-tdep.c
 - or1k-linux-tdep.c
 - sh-linux-tdep.c
 - sparc-linux-tdep.c
 - xtensa-linux-tdep.c

>  12 files changed, 82 insertions(+), 17 deletions(-)
> 
> diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
> index 63c200b47f7..b1225438d9d 100644
> --- a/gdb/aarch64-linux-tdep.c
> +++ b/gdb/aarch64-linux-tdep.c
> @@ -1795,7 +1795,7 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>    linux_init_abi (info, gdbarch, 1);
>  
>    set_solib_svr4_fetch_link_map_offsets (gdbarch,
> -					 svr4_lp64_fetch_link_map_offsets);
> +					 linux_lp64_fetch_link_map_offsets);
>  
>    /* Enable TLS support.  */
>    set_gdbarch_fetch_tls_load_module_address (gdbarch,
> diff --git a/gdb/alpha-linux-tdep.c b/gdb/alpha-linux-tdep.c
> index c2cffc13c20..0a00fc1f310 100644
> --- a/gdb/alpha-linux-tdep.c
> +++ b/gdb/alpha-linux-tdep.c
> @@ -374,7 +374,7 @@ alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>    set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
>  
>    set_solib_svr4_fetch_link_map_offsets
> -    (gdbarch, svr4_lp64_fetch_link_map_offsets);
> +    (gdbarch, linux_lp64_fetch_link_map_offsets);
>  
>    /* Enable TLS support.  */
>    set_gdbarch_fetch_tls_load_module_address (gdbarch,
> diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
> index ac6843c1fdd..715add8a7b0 100644
> --- a/gdb/amd64-linux-tdep.c
> +++ b/gdb/amd64-linux-tdep.c
> @@ -2042,7 +2042,7 @@ amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>  
>    /* GNU/Linux uses SVR4-style shared libraries.  */
>    set_solib_svr4_fetch_link_map_offsets
> -    (gdbarch, svr4_lp64_fetch_link_map_offsets);
> +    (gdbarch, linux_lp64_fetch_link_map_offsets);
>  
>    /* Register DTrace handlers.  */
>    set_gdbarch_dtrace_parse_probe_argument (gdbarch, amd64_dtrace_parse_probe_argument);
> @@ -2256,7 +2256,7 @@ amd64_x32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>  
>    /* GNU/Linux uses SVR4-style shared libraries.  */
>    set_solib_svr4_fetch_link_map_offsets
> -    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
> +    (gdbarch, linux_ilp32_fetch_link_map_offsets);
>  }
>  
>  void _initialize_amd64_linux_tdep ();
> diff --git a/gdb/ia64-linux-tdep.c b/gdb/ia64-linux-tdep.c
> index a17ec590002..71767ddf83e 100644
> --- a/gdb/ia64-linux-tdep.c
> +++ b/gdb/ia64-linux-tdep.c
> @@ -237,7 +237,7 @@ ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>    set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
>  
>    set_solib_svr4_fetch_link_map_offsets
> -    (gdbarch, svr4_lp64_fetch_link_map_offsets);
> +    (gdbarch, linux_lp64_fetch_link_map_offsets);
>  
>    /* Enable TLS support.  */
>    set_gdbarch_fetch_tls_load_module_address (gdbarch,
> diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
> index 637d3d36a0b..92ecedfd1cf 100644
> --- a/gdb/linux-tdep.c
> +++ b/gdb/linux-tdep.c
> @@ -41,6 +41,7 @@
>  #include "gdbsupport/gdb_optional.h"
>  #include "gcore.h"
>  #include "gcore-elf.h"
> +#include "solib-svr4.h"
>  
>  #include <ctype.h>
>  
> @@ -2724,3 +2725,62 @@ more information about this file, refer to the manpage of proc(5) and core(5).")
>  			   NULL, show_dump_excluded_mappings,
>  			   &setlist, &showlist);
>  }
> +
> +/* Fetch (and possibly build) an appropriate `struct link_map_offsets'
> +   for ILP32/LP64 Linux systems which don't have the r_ldsomap field.  */
> +
> +struct link_map_offsets *

Remove the `struct` keyword where possible.

> +linux_ilp32_fetch_link_map_offsets (void)

Remove void (here and at all other spots it appears).

> +{
> +  static struct link_map_offsets lmo;
> +  static struct link_map_offsets *lmp = NULL;

Replace NULL with nullptr throughout.

Simon

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] gdb: Don't assume r_ldsomap when r_version > 1 on Linux
  2021-08-17 13:09 ` Simon Marchi
@ 2021-08-17 13:44   ` H.J. Lu
  0 siblings, 0 replies; 5+ messages in thread
From: H.J. Lu @ 2021-08-17 13:44 UTC (permalink / raw)
  To: Simon Marchi; +Cc: GDB

On Tue, Aug 17, 2021 at 6:09 AM Simon Marchi <simon.marchi@polymtl.ca> wrote:
>
>
>
> On 2021-08-16 9:15 p.m., H.J. Lu via Gdb-patches wrote:
> > glibc is planning to add a field to support multiple namespaces.  But
> > there will be no r_ldsomap when r_version is bumped to 2.  Add
> > linux_[ilp32|lp64]_fetch_link_map_offsets to set r_ldsomap_offset to -1
> > and use them for Linux targets.
>
> As Carlos mentioned in the Buzilla thread, r_ldsomap is specific to
> Solaris.  It would be good to mention that in the commit message,
> because that helps understand the patch (and is probably not very well
> known).

I will send out the v2 patch with the updated commit message.

> Just to be clear, is this new version 2 specific to Linux or glibc?  A
> system using another libc won't use that layout, unless that other libc
> copies what glibc does?  I'm thinking that another libc could use
> version == 2, but for a different layout, in which case we would have to
> have callbacks specific to each libc.  Or, is there coordination between
> various libcs about how to evolve this layout?

We will discuss this with other Linux libcs to address.  I am extending
struct r_debug with:

   /* The following field is added by r_version == 2.  */

    /* Link to the next r_debug_extended structure.  Each r_debug_extended
       structure represents a different namespace.  The first
       r_debug_extended structure is for the default namespace.  */
    struct r_debug_extended *r_next;

If a Linux libc bumps r_version to 2, it needs to add r_next and set it
to NULL even if it is unused,

> >       PR gdb/28236
> >       * aarch64-linux-tdep.c (aarch64_linux_init_abi): Replace
> >       svr4_[ilp32|lp64]_fetch_link_map_offsets with
> >       linux_[ilp32|lp64]_fetch_link_map_offsets.
> >       * alpha-linux-tdep.c (alpha_linux_init_abi): Likewise.
> >       * amd64-linux-tdep.c (amd64_linux_init_abi): Likewise.
> >       (amd64_x32_linux_init_abi): Likewise.
> >       * ia64-linux-tdep.c (ia64_linux_init_abi): Likewise.
> >       * mips-linux-tdep.c (mips_linux_init_abi): Likewise.
> >       * ppc-linux-tdep.c (ppc_linux_init_abi): Likewise.
> >       * riscv-linux-tdep.c (riscv_linux_init_abi): Likewise.
> >       * s390-linux-tdep.c (s390_linux_init_abi_31): Likewise.
> >       (s390_linux_init_abi_64): Likewise.
> >       * sparc64-linux-tdep.c (sparc64_linux_init_abi): Likewise.
> >       * tilegx-linux-tdep.c (tilegx_linux_init_abi): Likewise.
> >       * linux-tdep.c: Include "solib-svr4.h".
> >       (linux_ilp32_fetch_link_map_offsets): New.
> >       (linux_lp64_fetch_link_map_offsets): Likewise.
> >       * linux-tdep.h (linux_ilp32_fetch_link_map_offsets): New.
> >       (linux_lp64_fetch_link_map_offsets): Likewise.
>
> Note that GDB doesn't use ChangeLogs anymore.  You can use
>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28236
>
> At the bottom to link to the Bugzilla entry.
>
> > ---
> >  gdb/aarch64-linux-tdep.c |  2 +-
> >  gdb/alpha-linux-tdep.c   |  2 +-
> >  gdb/amd64-linux-tdep.c   |  4 +--
> >  gdb/ia64-linux-tdep.c    |  2 +-
> >  gdb/linux-tdep.c         | 60 ++++++++++++++++++++++++++++++++++++++++
> >  gdb/linux-tdep.h         |  5 ++++
> >  gdb/mips-linux-tdep.c    |  6 ++--
> >  gdb/ppc-linux-tdep.c     |  4 +--
> >  gdb/riscv-linux-tdep.c   |  4 +--
> >  gdb/s390-linux-tdep.c    |  4 +--
> >  gdb/sparc64-linux-tdep.c |  2 +-
> >  gdb/tilegx-linux-tdep.c  |  4 +--
>
> I don't understand why some *-linux-tdep.c are changed but not all.  Do
> the following files need to be changed too?
>
>  - arc-linux-tdep.c
>  - arm-linux-tdep.c
>  - cris-linux-tdep.c
>  - csky-linux-tdep.c
>  - i386-linux-tdep.c
>  - m32r-linux-tdep.c
>  - m68k-linux-tdep.c
>  - microblaze-linux-tdep.c
>  - mn10300-linux-tdep.c
>  - nios2-linux-tdep.c
>  - or1k-linux-tdep.c
>  - sh-linux-tdep.c
>  - sparc-linux-tdep.c
>  - xtensa-linux-tdep.c

Will be fixed in the v2 patch.

> >  12 files changed, 82 insertions(+), 17 deletions(-)
> >
> > diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
> > index 63c200b47f7..b1225438d9d 100644
> > --- a/gdb/aarch64-linux-tdep.c
> > +++ b/gdb/aarch64-linux-tdep.c
> > @@ -1795,7 +1795,7 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> >    linux_init_abi (info, gdbarch, 1);
> >
> >    set_solib_svr4_fetch_link_map_offsets (gdbarch,
> > -                                      svr4_lp64_fetch_link_map_offsets);
> > +                                      linux_lp64_fetch_link_map_offsets);
> >
> >    /* Enable TLS support.  */
> >    set_gdbarch_fetch_tls_load_module_address (gdbarch,
> > diff --git a/gdb/alpha-linux-tdep.c b/gdb/alpha-linux-tdep.c
> > index c2cffc13c20..0a00fc1f310 100644
> > --- a/gdb/alpha-linux-tdep.c
> > +++ b/gdb/alpha-linux-tdep.c
> > @@ -374,7 +374,7 @@ alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> >    set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
> >
> >    set_solib_svr4_fetch_link_map_offsets
> > -    (gdbarch, svr4_lp64_fetch_link_map_offsets);
> > +    (gdbarch, linux_lp64_fetch_link_map_offsets);
> >
> >    /* Enable TLS support.  */
> >    set_gdbarch_fetch_tls_load_module_address (gdbarch,
> > diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
> > index ac6843c1fdd..715add8a7b0 100644
> > --- a/gdb/amd64-linux-tdep.c
> > +++ b/gdb/amd64-linux-tdep.c
> > @@ -2042,7 +2042,7 @@ amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> >
> >    /* GNU/Linux uses SVR4-style shared libraries.  */
> >    set_solib_svr4_fetch_link_map_offsets
> > -    (gdbarch, svr4_lp64_fetch_link_map_offsets);
> > +    (gdbarch, linux_lp64_fetch_link_map_offsets);
> >
> >    /* Register DTrace handlers.  */
> >    set_gdbarch_dtrace_parse_probe_argument (gdbarch, amd64_dtrace_parse_probe_argument);
> > @@ -2256,7 +2256,7 @@ amd64_x32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> >
> >    /* GNU/Linux uses SVR4-style shared libraries.  */
> >    set_solib_svr4_fetch_link_map_offsets
> > -    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
> > +    (gdbarch, linux_ilp32_fetch_link_map_offsets);
> >  }
> >
> >  void _initialize_amd64_linux_tdep ();
> > diff --git a/gdb/ia64-linux-tdep.c b/gdb/ia64-linux-tdep.c
> > index a17ec590002..71767ddf83e 100644
> > --- a/gdb/ia64-linux-tdep.c
> > +++ b/gdb/ia64-linux-tdep.c
> > @@ -237,7 +237,7 @@ ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> >    set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
> >
> >    set_solib_svr4_fetch_link_map_offsets
> > -    (gdbarch, svr4_lp64_fetch_link_map_offsets);
> > +    (gdbarch, linux_lp64_fetch_link_map_offsets);
> >
> >    /* Enable TLS support.  */
> >    set_gdbarch_fetch_tls_load_module_address (gdbarch,
> > diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
> > index 637d3d36a0b..92ecedfd1cf 100644
> > --- a/gdb/linux-tdep.c
> > +++ b/gdb/linux-tdep.c
> > @@ -41,6 +41,7 @@
> >  #include "gdbsupport/gdb_optional.h"
> >  #include "gcore.h"
> >  #include "gcore-elf.h"
> > +#include "solib-svr4.h"
> >
> >  #include <ctype.h>
> >
> > @@ -2724,3 +2725,62 @@ more information about this file, refer to the manpage of proc(5) and core(5).")
> >                          NULL, show_dump_excluded_mappings,
> >                          &setlist, &showlist);
> >  }
> > +
> > +/* Fetch (and possibly build) an appropriate `struct link_map_offsets'
> > +   for ILP32/LP64 Linux systems which don't have the r_ldsomap field.  */
> > +
> > +struct link_map_offsets *
>
> Remove the `struct` keyword where possible.

Fixed.

> > +linux_ilp32_fetch_link_map_offsets (void)
>
> Remove void (here and at all other spots it appears).

Fixed.

> > +{
> > +  static struct link_map_offsets lmo;
> > +  static struct link_map_offsets *lmp = NULL;
>
> Replace NULL with nullptr throughout.

Fixed.

> Simon

Thanks.

-- 
H.J.

^ permalink raw reply	[flat|nested] 5+ messages in thread
* [PATCH v2] gdb: Don't assume r_ldsomap when r_version > 1 on Linux
  2021-08-17  1:15 [PATCH] gdb: Don't assume r_ldsomap when r_version > 1 on Linux H.J. Lu
  2021-08-17 13:09 ` Simon Marchi
@ 2021-08-17 13:50 ` H.J. Lu
  2021-08-17 14:04   ` Simon Marchi
  1 sibling, 1 reply; 5+ messages in thread
From: H.J. Lu @ 2021-08-17 13:50 UTC (permalink / raw)
  To: GDB

The r_ldsomap field is specific to Solaris (part of librtld_db), and
should never be accessed for Linux.  glibc is planning to add a field
to support multiple namespaces.  But there will be no r_ldsomap when
r_version is bumped to 2.  Add linux_[ilp32|lp64]_fetch_link_map_offsets
to set r_ldsomap_offset to -1 and use them for Linux targets.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28236
---
 gdb/aarch64-linux-tdep.c    |  2 +-
 gdb/alpha-linux-tdep.c      |  2 +-
 gdb/amd64-linux-tdep.c      |  4 +--
 gdb/arc-linux-tdep.c        |  2 +-
 gdb/arm-linux-tdep.c        |  2 +-
 gdb/cris-linux-tdep.c       |  2 +-
 gdb/csky-linux-tdep.c       |  2 +-
 gdb/hppa-linux-tdep.c       |  2 +-
 gdb/i386-linux-tdep.c       |  2 +-
 gdb/ia64-linux-tdep.c       |  2 +-
 gdb/linux-tdep.c            | 60 +++++++++++++++++++++++++++++++++++++
 gdb/linux-tdep.h            |  5 ++++
 gdb/m32r-linux-tdep.c       |  2 +-
 gdb/m68k-linux-tdep.c       |  2 +-
 gdb/microblaze-linux-tdep.c |  2 +-
 gdb/mips-linux-tdep.c       |  6 ++--
 gdb/mn10300-linux-tdep.c    |  2 +-
 gdb/nios2-linux-tdep.c      |  2 +-
 gdb/or1k-linux-tdep.c       |  2 +-
 gdb/ppc-linux-tdep.c        |  4 +--
 gdb/riscv-linux-tdep.c      |  4 +--
 gdb/s390-linux-tdep.c       |  4 +--
 gdb/sh-linux-tdep.c         |  2 +-
 gdb/sparc-linux-tdep.c      |  2 +-
 gdb/sparc64-linux-tdep.c    |  2 +-
 gdb/tilegx-linux-tdep.c     |  4 +--
 gdb/xtensa-linux-tdep.c     |  2 +-
 27 files changed, 97 insertions(+), 32 deletions(-)

diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
index 63c200b47f7..b1225438d9d 100644
--- a/gdb/aarch64-linux-tdep.c
+++ b/gdb/aarch64-linux-tdep.c
@@ -1795,7 +1795,7 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   linux_init_abi (info, gdbarch, 1);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_lp64_fetch_link_map_offsets);
+					 linux_lp64_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/alpha-linux-tdep.c b/gdb/alpha-linux-tdep.c
index c2cffc13c20..0a00fc1f310 100644
--- a/gdb/alpha-linux-tdep.c
+++ b/gdb/alpha-linux-tdep.c
@@ -374,7 +374,7 @@ alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_lp64_fetch_link_map_offsets);
+    (gdbarch, linux_lp64_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
index ac6843c1fdd..715add8a7b0 100644
--- a/gdb/amd64-linux-tdep.c
+++ b/gdb/amd64-linux-tdep.c
@@ -2042,7 +2042,7 @@ amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_lp64_fetch_link_map_offsets);
+    (gdbarch, linux_lp64_fetch_link_map_offsets);
 
   /* Register DTrace handlers.  */
   set_gdbarch_dtrace_parse_probe_argument (gdbarch, amd64_dtrace_parse_probe_argument);
@@ -2256,7 +2256,7 @@ amd64_x32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 }
 
 void _initialize_amd64_linux_tdep ();
diff --git a/gdb/arc-linux-tdep.c b/gdb/arc-linux-tdep.c
index cf18b8d6b03..448fa370a36 100644
--- a/gdb/arc-linux-tdep.c
+++ b/gdb/arc-linux-tdep.c
@@ -732,7 +732,7 @@ arc_linux_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux uses SVR4-style shared libraries, with 32-bit ints, longs
      and pointers (ILP32).  */
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
 }
 
 /* Suppress warning from -Wmissing-prototypes.  */
diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index 773a93384f7..c0dfc5fcf3e 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -1763,7 +1763,7 @@ arm_linux_init_abi (struct gdbarch_info info,
   tdep->jb_elt_size = ARM_LINUX_JB_ELEMENT_SIZE;
 
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 
   /* Single stepping.  */
   set_gdbarch_software_single_step (gdbarch, arm_linux_software_single_step);
diff --git a/gdb/cris-linux-tdep.c b/gdb/cris-linux-tdep.c
index 4c1a4529986..68a12dbe0e9 100644
--- a/gdb/cris-linux-tdep.c
+++ b/gdb/cris-linux-tdep.c
@@ -43,7 +43,7 @@ cris_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 					       svr4_fetch_objfile_link_map);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
 
 }
 
diff --git a/gdb/csky-linux-tdep.c b/gdb/csky-linux-tdep.c
index e38ec652561..3a52a87b647 100644
--- a/gdb/csky-linux-tdep.c
+++ b/gdb/csky-linux-tdep.c
@@ -239,7 +239,7 @@ csky_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
   set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/hppa-linux-tdep.c b/gdb/hppa-linux-tdep.c
index 4bdaa1dfaee..52c642f0c7f 100644
--- a/gdb/hppa-linux-tdep.c
+++ b/gdb/hppa-linux-tdep.c
@@ -501,7 +501,7 @@ hppa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 
   tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
   set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
index c0df916ce6d..1c065eecb4d 100644
--- a/gdb/i386-linux-tdep.c
+++ b/gdb/i386-linux-tdep.c
@@ -1044,7 +1044,7 @@ i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 
   /* GNU/Linux uses the dynamic linker included in the GNU C Library.  */
   set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
diff --git a/gdb/ia64-linux-tdep.c b/gdb/ia64-linux-tdep.c
index a17ec590002..71767ddf83e 100644
--- a/gdb/ia64-linux-tdep.c
+++ b/gdb/ia64-linux-tdep.c
@@ -237,7 +237,7 @@ ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_lp64_fetch_link_map_offsets);
+    (gdbarch, linux_lp64_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index 637d3d36a0b..ae2f7c14f6d 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -41,6 +41,7 @@
 #include "gdbsupport/gdb_optional.h"
 #include "gcore.h"
 #include "gcore-elf.h"
+#include "solib-svr4.h"
 
 #include <ctype.h>
 
@@ -2724,3 +2725,62 @@ more information about this file, refer to the manpage of proc(5) and core(5).")
 			   NULL, show_dump_excluded_mappings,
 			   &setlist, &showlist);
 }
+
+/* Fetch (and possibly build) an appropriate `link_map_offsets' for
+   ILP32/LP64 Linux systems which don't have the r_ldsomap field.  */
+
+link_map_offsets *
+linux_ilp32_fetch_link_map_offsets ()
+{
+  static link_map_offsets lmo;
+  static link_map_offsets *lmp = nullptr;
+
+  if (lmp == nullptr)
+    {
+      lmp = &lmo;
+
+      lmo.r_version_offset = 0;
+      lmo.r_version_size = 4;
+      lmo.r_map_offset = 4;
+      lmo.r_brk_offset = 8;
+      lmo.r_ldsomap_offset = -1;
+
+      /* Everything we need is in the first 20 bytes.  */
+      lmo.link_map_size = 20;
+      lmo.l_addr_offset = 0;
+      lmo.l_name_offset = 4;
+      lmo.l_ld_offset = 8;
+      lmo.l_next_offset = 12;
+      lmo.l_prev_offset = 16;
+    }
+
+  return lmp;
+}
+
+link_map_offsets *
+linux_lp64_fetch_link_map_offsets ()
+{
+  static link_map_offsets lmo;
+  static link_map_offsets *lmp = nullptr;
+
+  if (lmp == nullptr)
+    {
+      lmp = &lmo;
+
+      lmo.r_version_offset = 0;
+      lmo.r_version_size = 4;
+      lmo.r_map_offset = 8;
+      lmo.r_brk_offset = 16;
+      lmo.r_ldsomap_offset = -1;
+
+      /* Everything we need is in the first 40 bytes.  */
+      lmo.link_map_size = 40;
+      lmo.l_addr_offset = 0;
+      lmo.l_name_offset = 8;
+      lmo.l_ld_offset = 16;
+      lmo.l_next_offset = 24;
+      lmo.l_prev_offset = 32;
+    }
+
+  return lmp;
+}
diff --git a/gdb/linux-tdep.h b/gdb/linux-tdep.h
index 28b60e46579..b5c1184bb09 100644
--- a/gdb/linux-tdep.h
+++ b/gdb/linux-tdep.h
@@ -98,4 +98,9 @@ extern CORE_ADDR linux_get_hwcap (struct target_ops *target);
    error, 0 is returned.  */
 extern CORE_ADDR linux_get_hwcap2 (struct target_ops *target);
 
+/* Fetch (and possibly build) an appropriate `struct link_map_offsets'
+   for ILP32 and LP64 Linux systems.  */
+extern struct link_map_offsets *linux_ilp32_fetch_link_map_offsets ();
+extern struct link_map_offsets *linux_lp64_fetch_link_map_offsets ();
+
 #endif /* linux-tdep.h */
diff --git a/gdb/m32r-linux-tdep.c b/gdb/m32r-linux-tdep.c
index 24807de0b2b..af0b5c01d04 100644
--- a/gdb/m32r-linux-tdep.c
+++ b/gdb/m32r-linux-tdep.c
@@ -461,7 +461,7 @@ m32r_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 
   /* Core file support.  */
   set_gdbarch_iterate_over_regset_sections
diff --git a/gdb/m68k-linux-tdep.c b/gdb/m68k-linux-tdep.c
index 7543a35e611..ad4d75adb4d 100644
--- a/gdb/m68k-linux-tdep.c
+++ b/gdb/m68k-linux-tdep.c
@@ -408,7 +408,7 @@ m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
 
   /* GNU/Linux uses the dynamic linker included in the GNU C Library.  */
   set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
diff --git a/gdb/microblaze-linux-tdep.c b/gdb/microblaze-linux-tdep.c
index 17cdc2516d4..e9ce7cd7fe0 100644
--- a/gdb/microblaze-linux-tdep.c
+++ b/gdb/microblaze-linux-tdep.c
@@ -124,7 +124,7 @@ microblaze_linux_init_abi (struct gdbarch_info info,
 
   /* Shared library handling.  */
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
 
   /* Trampolines.  */
   tramp_frame_prepend_unwinder (gdbarch,
diff --git a/gdb/mips-linux-tdep.c b/gdb/mips-linux-tdep.c
index 1ceed5250fe..ce287f6a354 100644
--- a/gdb/mips-linux-tdep.c
+++ b/gdb/mips-linux-tdep.c
@@ -1542,7 +1542,7 @@ mips_linux_init_abi (struct gdbarch_info info,
 	set_gdbarch_get_longjmp_target (gdbarch,
 					mips_linux_get_longjmp_target);
 	set_solib_svr4_fetch_link_map_offsets
-	  (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+	  (gdbarch, linux_ilp32_fetch_link_map_offsets);
 	tramp_frame_prepend_unwinder (gdbarch, &micromips_linux_o32_sigframe);
 	tramp_frame_prepend_unwinder (gdbarch,
 				      &micromips_linux_o32_rt_sigframe);
@@ -1554,7 +1554,7 @@ mips_linux_init_abi (struct gdbarch_info info,
 	set_gdbarch_get_longjmp_target (gdbarch,
 					mips_linux_get_longjmp_target);
 	set_solib_svr4_fetch_link_map_offsets
-	  (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+	  (gdbarch, linux_ilp32_fetch_link_map_offsets);
 	set_gdbarch_long_double_bit (gdbarch, 128);
 	/* These floatformats should probably be renamed.  MIPS uses
 	   the same 128-bit IEEE floating point format that IA-64 uses,
@@ -1570,7 +1570,7 @@ mips_linux_init_abi (struct gdbarch_info info,
 	set_gdbarch_get_longjmp_target (gdbarch,
 					mips64_linux_get_longjmp_target);
 	set_solib_svr4_fetch_link_map_offsets
-	  (gdbarch, svr4_lp64_fetch_link_map_offsets);
+	  (gdbarch, linux_lp64_fetch_link_map_offsets);
 	set_gdbarch_long_double_bit (gdbarch, 128);
 	/* These floatformats should probably be renamed.  MIPS uses
 	   the same 128-bit IEEE floating point format that IA-64 uses,
diff --git a/gdb/mn10300-linux-tdep.c b/gdb/mn10300-linux-tdep.c
index 1a2e0493118..7c68d1116c5 100644
--- a/gdb/mn10300-linux-tdep.c
+++ b/gdb/mn10300-linux-tdep.c
@@ -709,7 +709,7 @@ am33_linux_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_iterate_over_regset_sections
     (gdbarch, am33_iterate_over_regset_sections);
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 
   tramp_frame_prepend_unwinder (gdbarch, &am33_linux_sigframe);
   tramp_frame_prepend_unwinder (gdbarch, &am33_linux_rt_sigframe);
diff --git a/gdb/nios2-linux-tdep.c b/gdb/nios2-linux-tdep.c
index 661c8b38f72..bd86146c878 100644
--- a/gdb/nios2-linux-tdep.c
+++ b/gdb/nios2-linux-tdep.c
@@ -226,7 +226,7 @@ nios2_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 					     svr4_fetch_objfile_link_map);
diff --git a/gdb/or1k-linux-tdep.c b/gdb/or1k-linux-tdep.c
index 1c3f8db7492..2ad55f0d9ec 100644
--- a/gdb/or1k-linux-tdep.c
+++ b/gdb/or1k-linux-tdep.c
@@ -143,7 +143,7 @@ or1k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   linux_init_abi (info, gdbarch, 0);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index 1e94922f25a..e62f45a35d8 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -2035,7 +2035,7 @@ ppc_linux_init_abi (struct gdbarch_info info,
       /* Shared library handling.  */
       set_gdbarch_skip_trampoline_code (gdbarch, ppc_skip_trampoline_code);
       set_solib_svr4_fetch_link_map_offsets
-	(gdbarch, svr4_ilp32_fetch_link_map_offsets);
+	(gdbarch, linux_ilp32_fetch_link_map_offsets);
 
       /* Setting the correct XML syscall filename.  */
       set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_PPC);
@@ -2087,7 +2087,7 @@ ppc_linux_init_abi (struct gdbarch_info info,
       /* Shared library handling.  */
       set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
       set_solib_svr4_fetch_link_map_offsets
-	(gdbarch, svr4_lp64_fetch_link_map_offsets);
+	(gdbarch, linux_lp64_fetch_link_map_offsets);
 
       /* Setting the correct XML syscall filename.  */
       set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_PPC64);
diff --git a/gdb/riscv-linux-tdep.c b/gdb/riscv-linux-tdep.c
index 49dc75bb618..7351e1901d6 100644
--- a/gdb/riscv-linux-tdep.c
+++ b/gdb/riscv-linux-tdep.c
@@ -187,8 +187,8 @@ riscv_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 					 (riscv_isa_xlen (gdbarch) == 4
-					  ? svr4_ilp32_fetch_link_map_offsets
-					  : svr4_lp64_fetch_link_map_offsets));
+					  ? linux_ilp32_fetch_link_map_offsets
+					  : linux_lp64_fetch_link_map_offsets));
 
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
diff --git a/gdb/s390-linux-tdep.c b/gdb/s390-linux-tdep.c
index 1f40e10e3d3..04e3fc640d2 100644
--- a/gdb/s390-linux-tdep.c
+++ b/gdb/s390-linux-tdep.c
@@ -1158,7 +1158,7 @@ s390_linux_init_abi_31 (struct gdbarch_info info, struct gdbarch *gdbarch)
   s390_linux_init_abi_any (info, gdbarch);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_ilp32_fetch_link_map_offsets);
+					 linux_ilp32_fetch_link_map_offsets);
   set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_S390);
 }
 
@@ -1174,7 +1174,7 @@ s390_linux_init_abi_64 (struct gdbarch_info info, struct gdbarch *gdbarch)
   s390_linux_init_abi_any (info, gdbarch);
 
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					 svr4_lp64_fetch_link_map_offsets);
+					 linux_lp64_fetch_link_map_offsets);
   set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_S390X);
 }
 
diff --git a/gdb/sh-linux-tdep.c b/gdb/sh-linux-tdep.c
index 700df35bc3b..8315d46fddf 100644
--- a/gdb/sh-linux-tdep.c
+++ b/gdb/sh-linux-tdep.c
@@ -189,7 +189,7 @@ sh_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux uses SVR4-style shared libraries.  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
   set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
 
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/sparc-linux-tdep.c b/gdb/sparc-linux-tdep.c
index 8d8efb49911..4ad77e24d82 100644
--- a/gdb/sparc-linux-tdep.c
+++ b/gdb/sparc-linux-tdep.c
@@ -436,7 +436,7 @@ sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux has SVR4-style shared libraries...  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 
   /* ...which means that we need some special handling when doing
      prologue analysis.  */
diff --git a/gdb/sparc64-linux-tdep.c b/gdb/sparc64-linux-tdep.c
index ea692ac00ef..e63fa87c69b 100644
--- a/gdb/sparc64-linux-tdep.c
+++ b/gdb/sparc64-linux-tdep.c
@@ -383,7 +383,7 @@ sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux has SVR4-style shared libraries...  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_lp64_fetch_link_map_offsets);
+    (gdbarch, linux_lp64_fetch_link_map_offsets);
 
   /* ...which means that we need some special handling when doing
      prologue analysis.  */
diff --git a/gdb/tilegx-linux-tdep.c b/gdb/tilegx-linux-tdep.c
index 382e7f6d908..353497a3434 100644
--- a/gdb/tilegx-linux-tdep.c
+++ b/gdb/tilegx-linux-tdep.c
@@ -121,10 +121,10 @@ tilegx_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* GNU/Linux uses SVR4-style shared libraries.  */
   if (arch_size == 32)
     set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					   svr4_ilp32_fetch_link_map_offsets);
+					   linux_ilp32_fetch_link_map_offsets);
   else
     set_solib_svr4_fetch_link_map_offsets (gdbarch,
-					   svr4_lp64_fetch_link_map_offsets);
+					   linux_lp64_fetch_link_map_offsets);
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
diff --git a/gdb/xtensa-linux-tdep.c b/gdb/xtensa-linux-tdep.c
index 2eba9aaa21d..c9e2519b1e7 100644
--- a/gdb/xtensa-linux-tdep.c
+++ b/gdb/xtensa-linux-tdep.c
@@ -113,7 +113,7 @@ xtensa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   linux_init_abi (info, gdbarch, 0);
 
   set_solib_svr4_fetch_link_map_offsets
-    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+    (gdbarch, linux_ilp32_fetch_link_map_offsets);
 
   set_gdbarch_gdb_signal_from_target (gdbarch,
 				      xtensa_linux_gdb_signal_from_target);
-- 
2.31.1


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH v2] gdb: Don't assume r_ldsomap when r_version > 1 on Linux
  2021-08-17 13:50 ` [PATCH v2] " H.J. Lu
@ 2021-08-17 14:04   ` Simon Marchi
  0 siblings, 0 replies; 5+ messages in thread
From: Simon Marchi @ 2021-08-17 14:04 UTC (permalink / raw)
  To: H.J. Lu, GDB



On 2021-08-17 9:50 a.m., H.J. Lu wrote:
> The r_ldsomap field is specific to Solaris (part of librtld_db), and
> should never be accessed for Linux.  glibc is planning to add a field
> to support multiple namespaces.  But there will be no r_ldsomap when
> r_version is bumped to 2.  Add linux_[ilp32|lp64]_fetch_link_map_offsets
> to set r_ldsomap_offset to -1 and use them for Linux targets.
> 
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28236
> ---
>  gdb/aarch64-linux-tdep.c    |  2 +-
>  gdb/alpha-linux-tdep.c      |  2 +-
>  gdb/amd64-linux-tdep.c      |  4 +--
>  gdb/arc-linux-tdep.c        |  2 +-
>  gdb/arm-linux-tdep.c        |  2 +-
>  gdb/cris-linux-tdep.c       |  2 +-
>  gdb/csky-linux-tdep.c       |  2 +-
>  gdb/hppa-linux-tdep.c       |  2 +-
>  gdb/i386-linux-tdep.c       |  2 +-
>  gdb/ia64-linux-tdep.c       |  2 +-
>  gdb/linux-tdep.c            | 60 +++++++++++++++++++++++++++++++++++++
>  gdb/linux-tdep.h            |  5 ++++
>  gdb/m32r-linux-tdep.c       |  2 +-
>  gdb/m68k-linux-tdep.c       |  2 +-
>  gdb/microblaze-linux-tdep.c |  2 +-
>  gdb/mips-linux-tdep.c       |  6 ++--
>  gdb/mn10300-linux-tdep.c    |  2 +-
>  gdb/nios2-linux-tdep.c      |  2 +-
>  gdb/or1k-linux-tdep.c       |  2 +-
>  gdb/ppc-linux-tdep.c        |  4 +--
>  gdb/riscv-linux-tdep.c      |  4 +--
>  gdb/s390-linux-tdep.c       |  4 +--
>  gdb/sh-linux-tdep.c         |  2 +-
>  gdb/sparc-linux-tdep.c      |  2 +-
>  gdb/sparc64-linux-tdep.c    |  2 +-
>  gdb/tilegx-linux-tdep.c     |  4 +--
>  gdb/xtensa-linux-tdep.c     |  2 +-
>  27 files changed, 97 insertions(+), 32 deletions(-)

LGTM, thanks.

Simon

^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-08-17 14:04 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-17  1:15 [PATCH] gdb: Don't assume r_ldsomap when r_version > 1 on Linux H.J. Lu
2021-08-17 13:09 ` Simon Marchi
2021-08-17 13:44   ` H.J. Lu
2021-08-17 13:50 ` [PATCH v2] " H.J. Lu
2021-08-17 14:04   ` Simon Marchi

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