[PATCH v2 09/10] Ptrace support for AArch64 SVE gdbsever

Alan Hayward
2018-06-06T15:17:29Z

Add checks to detect SVE tdesc. Easiest way to do this is by checking the
size of the vector registers.

Use the common aarch64 ptrace copy functions for reading/writing registers.
A wrapper is required due to the common functions using reg_buffer_common.

2018-06-06 Alan Hayward <alan.hayward@arm.com>

gdbserver/
* linux-aarch64-low.c (is_sve_tdesc): New function.
(aarch64_sve_regs_copy_to_regcache): Likewise.
(aarch64_sve_regs_copy_from_regcache): Likewise.
(aarch64_regs_info): Add SVE checks.
(initialize_low_arch): Initialize SVE.
---
gdb/gdbserver/linux-aarch64-low.c | 62 +++++++++++++++++++++++++++++++++++++--
1 file changed, 59 insertions(+), 3 deletions(-)

diff --git a/gdb/gdbserver/linux-aarch64-low.c b/gdb/gdbserver/linux-aarch64-low.c
index 9db9a7c1c3..e7fec25a64 100644
--- a/gdb/gdbserver/linux-aarch64-low.c
+++ b/gdb/gdbserver/linux-aarch64-low.c
@@ -73,6 +73,16 @@ is_64bit_tdesc (void)
return register_size (regcache->tdesc, 0) == 8;
}

+static bool
+is_sve_tdesc (void)
+{
+ struct regcache *regcache = get_thread_regcache (current_thread, 0);
+
+ /* Mimimum size of Z0 on SVE is 256bit. If not SVE, then Z0 will be the
+ 128bit V0 register. */
+ return register_size (regcache->tdesc, AARCH64_SVE_Z0_REGNUM) >= 32;
+}
+
/* Implementation of linux_target_ops method "cannot_store_register". */

static int
@@ -514,6 +524,22 @@ aarch64_arch_setup (void)
aarch64_linux_get_debug_reg_capacity (lwpid_of (current_thread));
}

+/* Wrapper for aarch64_sve_regs_copy_to_reg_buf. */
+
+static void
+aarch64_sve_regs_copy_to_regcache (struct regcache *regcache, const void *buf)
+{
+ return aarch64_sve_regs_copy_to_reg_buf (regcache, buf);
+}
+
+/* Wrapper for aarch64_sve_regs_copy_from_reg_buf. */
+
+static void
+aarch64_sve_regs_copy_from_regcache (struct regcache *regcache, void *buf)
+{
+ return aarch64_sve_regs_copy_from_reg_buf (regcache, buf);
+}
+
static struct regset_info aarch64_regsets[] =
{
{ PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS,
@@ -540,15 +566,44 @@ static struct regs_info regs_info_aarch64 =
&aarch64_regsets_info,
};

+static struct regset_info aarch64_sve_regsets[] =
+{
+ { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS,
+ sizeof (struct user_pt_regs), GENERAL_REGS,
+ aarch64_fill_gregset, aarch64_store_gregset },
+ { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_ARM_SVE,
+ SVE_PT_SIZE (AARCH64_MAX_SVE_VQ, SVE_PT_REGS_SVE), EXTENDED_REGS,
+ aarch64_sve_regs_copy_from_regcache, aarch64_sve_regs_copy_to_regcache
+ },
+ NULL_REGSET
+};
+
+static struct regsets_info aarch64_sve_regsets_info =
+ {
+ aarch64_sve_regsets, /* regsets. */
+ 0, /* num_regsets. */
+ NULL, /* disabled_regsets. */
+ };
+
+static struct regs_info regs_info_aarch64_sve =
+ {
+ NULL, /* regset_bitmap. */
+ NULL, /* usrregs. */
+ &aarch64_sve_regsets_info,
+ };
+
/* Implementation of linux_target_ops method "regs_info". */

static const struct regs_info *
aarch64_regs_info (void)
{
- if (is_64bit_tdesc ())
- return &regs_info_aarch64;
- else
+ if (!is_64bit_tdesc ())
return &regs_info_aarch32;
+
+ if (is_sve_tdesc ())
+ return &regs_info_aarch64_sve;
+
+ return &regs_info_aarch64;
}

/* Implementation of linux_target_ops method "supports_tracepoints". */
@@ -3027,6 +3082,7 @@ initialize_low_arch (void)
initialize_low_arch_aarch32 ();

initialize_regsets_info (&aarch64_regsets_info);
+ initialize_regsets_info (&aarch64_sve_regsets_info);

#if GDB_SELF_TEST
initialize_low_tdesc ();
--
2.15.1 (Apple Git-101)