[binutils-gdb] gdb/riscv: Fix assertion in inferior call code

[Andrew Burgess <aburgess at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=8c49aa89abb92516dfc3507b540f736ca6339c0c

commit 8c49aa89abb92516dfc3507b540f736ca6339c0c
Author: Andrew Burgess <andrew.burgess@embecosm.com>
Date:   Sun Apr 8 11:08:32 2018 +0100

    gdb/riscv: Fix assertion in inferior call code
    
    An assertion when setting up arguments for an inferior call checks the
    size of the argument against xlen.  However, if xlen and flen are
    different sizes, and the argument is being placed into a floating
    pointer register then we should be comparing against flen not xlen.
    
    This issue shows up as an assertion failure when running on an rv32g
    target with a binary compiled using the rv32f abi and making an
    inferior call involving large floating point arguments, for example
    the test gdb.base/infcall-nested-structs.exp.
    
    gdb/ChangeLog:
    
    	* riscv-tdep.c (riscv_is_fp_regno_p): New function.
    	(riscv_register_reggroup_p): Use new function, remove unneeded
    	parenthesis.
    	(riscv_push_dummy_call): Extend assert to compare against xlen or
    	flen based on register type.

Diff:
---
 gdb/ChangeLog    |  8 ++++++++
 gdb/riscv-tdep.c | 21 ++++++++++++++++-----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index bae1d91..fb0612c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,13 @@
 2018-07-10  Andrew Burgess  <andrew.burgess@embecosm.com>
 
+	* riscv-tdep.c (riscv_is_fp_regno_p): New function.
+	(riscv_register_reggroup_p): Use new function, remove unneeded
+	parenthesis.
+	(riscv_push_dummy_call): Extend assert to compare against xlen or
+	flen based on register type.
+
+2018-07-10  Andrew Burgess  <andrew.burgess@embecosm.com>
+
 	* riscv-tdep.c (riscv_print_arg_location): Use TYPE_SAFE_NAME.
 
 2018-07-09  Andrew Burgess  <andrew.burgess@embecosm.com>
diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index e2be993..25a8fda 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -413,6 +413,15 @@ riscv_has_fp_abi (struct gdbarch *gdbarch)
   return (gdbarch_tdep (gdbarch)->abi.fields.float_abi != 0);
 }
 
+/* Return true if REGNO is a floating pointer register.  */
+
+static bool
+riscv_is_fp_regno_p (int regno)
+{
+  return (regno >= RISCV_FIRST_FP_REGNUM
+	  && regno <= RISCV_LAST_FP_REGNUM);
+}
+
 /* Implement the breakpoint_kind_from_pc gdbarch method.  */
 
 static int
@@ -787,10 +796,10 @@ riscv_register_reggroup_p (struct gdbarch  *gdbarch, int regnum,
       return 0;
     }
   else if (reggroup == float_reggroup)
-    return ((regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM)
-	    || (regnum == RISCV_CSR_FCSR_REGNUM
-		|| regnum == RISCV_CSR_FFLAGS_REGNUM
-	        || regnum == RISCV_CSR_FRM_REGNUM));
+    return (riscv_is_fp_regno_p (regnum)
+	    || regnum == RISCV_CSR_FCSR_REGNUM
+	    || regnum == RISCV_CSR_FFLAGS_REGNUM
+	    || regnum == RISCV_CSR_FRM_REGNUM);
   else if (reggroup == general_reggroup)
     return regnum < RISCV_FIRST_FP_REGNUM;
   else if (reggroup == restore_reggroup || reggroup == save_reggroup)
@@ -2154,7 +2163,9 @@ riscv_push_dummy_call (struct gdbarch *gdbarch,
 	      {
 		gdb_byte tmp [sizeof (ULONGEST)];
 
-		gdb_assert (second_arg_length <= call_info.xlen);
+		gdb_assert ((riscv_is_fp_regno_p (info->argloc[1].loc_data.regno)
+			     && second_arg_length <= call_info.flen)
+			    || second_arg_length <= call_info.xlen);
 		memset (tmp, 0, sizeof (tmp));
 		memcpy (tmp, second_arg_data, second_arg_length);
 		regcache->cooked_write (info->argloc[1].loc_data.regno, tmp);