Re: [Libunwind-devel] A modification suggestion on MIPS64 N32 on libunwind

[Deng, Yimin (NSB - CN/Shanghai)]

Hello,
I'm sorry for that. Thanks for your reminding!

Rebased (B.T.W. I have only N32 setup, so I'm not so sure whether it will 
affect other ABIs):

diff --git a/include/libunwind-mips.h b/include/libunwind-mips.h
--- a/include/libunwind-mips.h
+++ b/include/libunwind-mips.h
@@ -98,7 +98,7 @@ typedef enum
     UNW_MIPS_R30,
     UNW_MIPS_R31,
 
-    UNW_MIPS_PC = 34,
+    UNW_MIPS_PC = 64,
 
     /* FIXME: Other registers!  */
 
diff --git a/include/tdep-mips/libunwind_i.h b/include/tdep-mips/libunwind_i.h
--- a/include/tdep-mips/libunwind_i.h
+++ b/include/tdep-mips/libunwind_i.h
@@ -247,6 +247,14 @@ dwarf_get (struct dwarf_cursor *c, dwarf
                                      0, c->as_arg);
   else if (c->as->abi == UNW_MIPS_ABI_O32)
     return read_s32 (c, DWARF_GET_LOC (loc), val);
+  else if (c->as->abi == UNW_MIPS_ABI_N32) {
+    if (tdep_big_endian(c->as))
+      return (*c->as->acc.access_mem) (c->as, DWARF_GET_LOC (loc) + 4, val,
+                                       0, c->as_arg);
+    else
+      return (*c->as->acc.access_mem) (c->as, DWARF_GET_LOC (loc), val,
+                                       0, c->as_arg);
+  }
   else
     return (*c->as->acc.access_mem) (c->as, DWARF_GET_LOC (loc), val,
                                      0, c->as_arg);
diff --git a/src/mips/Gcreate_addr_space.c b/src/mips/Gcreate_addr_space.c
--- a/src/mips/Gcreate_addr_space.c
+++ b/src/mips/Gcreate_addr_space.c
@@ -58,7 +58,15 @@ unw_create_addr_space (unw_accessors_t *
     as->big_endian = (byte_order == __BIG_ENDIAN);
 
   /* FIXME!  There is no way to specify the ABI.  */
+#if _MIPS_SIM == _ABIO32
   as->abi = UNW_MIPS_ABI_O32;
+#elif _MIPS_SIM == _ABIN32
+  as->abi = UNW_MIPS_ABI_N32;
+#elif _MIPS_SIM == _ABI64
+  as->abi = UNW_MIPS_ABI_N64;
+#else
+# error Unsupported ABI
+#endif
   as->addr_size = 4;
 
   return as;
diff --git a/src/mips/Gregs.c b/src/mips/Gregs.c
--- a/src/mips/Gregs.c
+++ b/src/mips/Gregs.c
@@ -63,7 +63,7 @@ tdep_access_reg (struct cursor *c, unw_r
     case UNW_MIPS_R26:
     case UNW_MIPS_R27:
     case UNW_MIPS_R28:
-    case UNW_MIPS_R29:
+
     case UNW_MIPS_R30:
     case UNW_MIPS_R31:
       loc = c->dwarf.loc[reg - UNW_MIPS_R0];
@@ -75,6 +75,7 @@ tdep_access_reg (struct cursor *c, unw_r
       loc = c->dwarf.loc[reg];
       break;
 
+    case UNW_MIPS_R29:
     case UNW_MIPS_CFA:
       if (write)
         return -UNW_EREADONLYREG;

B.R.
Yimin Deng

-----Original Message-----
From: Dave Watson [mailto:address@hidden 
Sent: 2018年4月17日 22:57
To: Deng, Yimin (NSB - CN/Shanghai)
Cc: address@hidden
Subject: Re: [Libunwind-devel] A modification suggestion on MIPS64 N32 on 
libunwind

Hello, 

On 04/16/18 07:15 AM, Deng, Yimin (NSB - CN/Shanghai) wrote:
> Hi,
> I really appreciate for all your contribution to the libunwind. I mainly used 
> the library 'unwind-ptrace' and it's very useful.
> 
> But I find that there are some issues when use it on MIPS64 (ABI: N32). After 
> doing the modifications(based on libunwind-1.2.1) below, it works well.
> I hope this will help you if you are suffering issues on the same arch and 
> ABI.

It appears parts of this patch have already been added to master.  Can you 
rebase this on top of the master branch and resend?  Thanks!