[binutils-gdb] gdb/arm: Include FType bit in EXC_RETURN pattern on v8m

[Torbjorn Svensson <azoff@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=8db533e7d6d28db1be0ae4c95ddea7aa3a6224c8

commit 8db533e7d6d28db1be0ae4c95ddea7aa3a6224c8
Author: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>
Date:   Wed Nov 23 11:58:31 2022 +0100

    gdb/arm: Include FType bit in EXC_RETURN pattern on v8m
    
    For v8m, the EXC_RETURN pattern, without security extension, consists of
    FType, Mode and SPSEL.  These are the same bits that are used in v7m.
    This patch extends the list of patterns to include also the FType bit
    and not just Mode and SPSEL bits for v8m targets without security
    extension.
    
    Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>

Diff:
---
 gdb/arm-tdep.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index a839f957440..6f02f04b5cb 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -828,13 +828,17 @@ arm_m_addr_is_lockup (CORE_ADDR addr)
    For more details see "B1.5.8 Exception return behavior"
    in both ARMv6-M and ARMv7-M Architecture Reference Manuals.
 
-   In the ARMv8-M Architecture Technical Reference also adds
-   for implementations without the Security Extension:
+   From ARMv8-M Architecture Technical Reference, D1.2.95
+   FType, Mode and SPSEL bits are to be considered when the Security
+   Extension is not implemented.
 
-   EXC_RETURN    Condition
-   0xFFFFFFB0    Return to Handler mode.
-   0xFFFFFFB8    Return to Thread mode using the main stack.
-   0xFFFFFFBC    Return to Thread mode using the process stack.  */
+   EXC_RETURN    Return To        Return Stack    Frame Type
+   0xFFFFFFA0    Handler mode     Main            Extended
+   0xFFFFFFA8    Thread mode      Main            Extended
+   0xFFFFFFAC    Thread mode      Process         Extended
+   0xFFFFFFB0    Handler mode     Main            Standard
+   0xFFFFFFB8    Thread mode      Main            Standard
+   0xFFFFFFBC    Thread mode      Process         Standard  */
 
 static int
 arm_m_addr_is_magic (struct gdbarch *gdbarch, CORE_ADDR addr)
@@ -859,6 +863,9 @@ arm_m_addr_is_magic (struct gdbarch *gdbarch, CORE_ADDR addr)
       switch (addr)
 	{
 	  /* Values from ARMv8-M Architecture Technical Reference.  */
+	case 0xffffffa0:
+	case 0xffffffa8:
+	case 0xffffffac:
 	case 0xffffffb0:
 	case 0xffffffb8:
 	case 0xffffffbc: