This is the mail archive of the gdb-patches@sourceware.org mailing list for the GDB project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH 3/3] gdbserver: xtensa: add call0 support


On 01/18/2017 05:50 PM, Max Filippov wrote:
Correctly handle a0- registers on requests from remote gdb. This fixes

  'Register 1 is not available'

and subsequent assertion in the remote gdb connecting to the gdbserver:

  'findvar.c:291: internal-error: value_of_register_lazy:
    Assertion `frame_id_p(get_frame_id (frame))' failed.'

The register structure is the same for windowed and call0 ABIs because
currently linux kernel internally requires windowed registers, so they
are always present.

2017-01-18  Max Filippov  <jcmvbkbc@gmail.com>
gdb/gdbserver/

Drop gdb/gdbserver/

	* linux-xtensa-low.c (C0_NREGS): New definition.
	(xtensa_fill_gregset): Call collect_register for all registers in
	a0_regnum..a0_regnum + C0_NREGS range.
	(xtensa_store_gregset): Call supply_register for all registers in
	a0_regnum..a0_regnum + C0_NREGS range.
---
 gdb/gdbserver/linux-xtensa-low.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/gdb/gdbserver/linux-xtensa-low.c b/gdb/gdbserver/linux-xtensa-low.c
index 98c0bf2..73fbfe2 100644
--- a/gdb/gdbserver/linux-xtensa-low.c
+++ b/gdb/gdbserver/linux-xtensa-low.c
@@ -39,12 +39,15 @@ enum regnum {
 	R_A0 = 64
 };

+#define C0_NREGS 16
+

This is duplicating code from gdb/xtensa-linux-nat. Common nat code could be added to gdb/nat/ in an xtensa-specific file.

 static void
 xtensa_fill_gregset (struct regcache *regcache, void *buf)
 {
   elf_greg_t* rset = (elf_greg_t*)buf;
   const struct target_desc *tdesc = regcache->tdesc;
   int ar0_regnum;
+  int a0_regnum;
   char *ptr;
   int i;

@@ -72,6 +75,17 @@ xtensa_fill_gregset (struct regcache *regcache, void *buf)
   collect_register_by_name (regcache, "ps", (char*)&rset[R_PS]);
   collect_register_by_name (regcache, "windowbase", (char*)&rset[R_WB]);
   collect_register_by_name (regcache, "windowstart", (char*)&rset[R_WS]);
+
+  a0_regnum = find_regno (tdesc, "a0");
+  ptr = (char *)&rset[R_A0 + 4 * rset[R_WB]];

(char *) &rset... with space.

More occurrences of this below.

+
+  for (i = a0_regnum; i < a0_regnum + C0_NREGS; i++)
+    {
+      if (4 * rset[R_WB] + i - a0_regnum == XCHAL_NUM_AREGS)

This looks slightly error-prone. Adding parenthesis around the expression would look better and avoid compiler warnings.

+	ptr = (char *)&rset[R_A0];

space issue mentioned above.

+      collect_register (regcache, i, ptr);
+      ptr += register_size (tdesc, i);
+    }
 }

 static void
@@ -80,6 +94,7 @@ xtensa_store_gregset (struct regcache *regcache, const void *buf)
   const elf_greg_t* rset = (const elf_greg_t*)buf;
   const struct target_desc *tdesc = regcache->tdesc;
   int ar0_regnum;
+  int a0_regnum;
   char *ptr;
   int i;

@@ -94,6 +109,17 @@ xtensa_store_gregset (struct regcache *regcache, const void *buf)
       ptr += register_size (tdesc, i);
     }

+  a0_regnum = find_regno (tdesc, "a0");
+  ptr = (char *)&rset[R_A0 + (4 * rset[R_WB]) % XCHAL_NUM_AREGS];
+

space issue.

+  for (i = a0_regnum; i < a0_regnum + C0_NREGS; i++)
+    {
+      if (4 * rset[R_WB] + i - a0_regnum == XCHAL_NUM_AREGS)

parenthesis around the expression.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]