diff mbox series

[v6,09/15] gdb: Support XSAVE layouts for the current host in the Linux x86 targets.

Message ID 20230714155151.21723-10-jhb@FreeBSD.org
State New
Headers
Series Handle variable XSAVE layouts |

Commit Message

John Baldwin July 14, 2023, 3:51 p.m. UTC 
  Note that this uses the CPUID instruction to determine the total size
of the XSAVE register set.  If there is a way to fetch the register set
size using ptrace that would probably be better.
---
 gdb/amd64-linux-nat.c | 6 ++++--
 gdb/configure.nat     | 3 ++-
 gdb/i386-linux-nat.c  | 8 ++++++--
 gdb/x86-linux-nat.c   | 3 +++
 gdb/x86-linux-nat.h   | 7 +++++++
 5 files changed, 22 insertions(+), 5 deletions(-)

Comments

Simon Marchi July 26, 2023, 8:51 p.m. UTC | #1 
On 7/14/23 11:51, John Baldwin wrote:
> Note that this uses the CPUID instruction to determine the total size
> of the XSAVE register set.  If there is a way to fetch the register set
> size using ptrace that would probably be better.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon
diff mbox series

Patch

diff --git a/gdb/amd64-linux-nat.c b/gdb/amd64-linux-nat.c
index b5b0703879b..6571be40bb5 100644
--- a/gdb/amd64-linux-nat.c
+++ b/gdb/amd64-linux-nat.c
@@ -210,6 +210,7 @@  void
 amd64_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum)
 {
   struct gdbarch *gdbarch = regcache->arch ();
+  const i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
   int tid;
 
   /* GNU/Linux LWP ID's are process ID's.  */
@@ -235,7 +236,7 @@  amd64_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum)
 
       if (have_ptrace_getregset == TRIBOOL_TRUE)
 	{
-	  char xstateregs[X86_XSTATE_MAX_SIZE];
+	  char xstateregs[tdep->xsave_layout.sizeof_xsave];
 	  struct iovec iov;
 
 	  /* Pre-4.14 kernels have a bug (fixed by commit 0852b374173b
@@ -270,6 +271,7 @@  void
 amd64_linux_nat_target::store_registers (struct regcache *regcache, int regnum)
 {
   struct gdbarch *gdbarch = regcache->arch ();
+  const i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
   int tid;
 
   /* GNU/Linux LWP ID's are process ID's.  */
@@ -299,7 +301,7 @@  amd64_linux_nat_target::store_registers (struct regcache *regcache, int regnum)
 
       if (have_ptrace_getregset == TRIBOOL_TRUE)
 	{
-	  char xstateregs[X86_XSTATE_MAX_SIZE];
+	  char xstateregs[tdep->xsave_layout.sizeof_xsave];
 	  struct iovec iov;
 
 	  iov.iov_base = xstateregs;
diff --git a/gdb/configure.nat b/gdb/configure.nat
index b371ad89afe..2739d14a1c4 100644
--- a/gdb/configure.nat
+++ b/gdb/configure.nat
@@ -254,6 +254,7 @@  case ${gdb_host} in
 	    i386)
 		# Host: Intel 386 running GNU/Linux.
 		NATDEPFILES="${NATDEPFILES} x86-nat.o nat/x86-dregs.o \
+		nat/x86-xstate.o \
 		i386-linux-nat.o x86-linux-nat.o nat/linux-btrace.o \
 		nat/x86-linux.o nat/x86-linux-dregs.o"
 		;;
@@ -319,7 +320,7 @@  case ${gdb_host} in
 	    i386)
 		# Host: GNU/Linux x86-64
 		NATDEPFILES="${NATDEPFILES} x86-nat.o nat/x86-dregs.o \
-		amd64-nat.o amd64-linux-nat.o x86-linux-nat.o \
+		nat/x86-xstate.o amd64-nat.o amd64-linux-nat.o x86-linux-nat.o \
 		nat/linux-btrace.o \
 		nat/x86-linux.o nat/x86-linux-dregs.o \
 		nat/amd64-linux-siginfo.o"
diff --git a/gdb/i386-linux-nat.c b/gdb/i386-linux-nat.c
index a524fdc9a1d..7e0572e1907 100644
--- a/gdb/i386-linux-nat.c
+++ b/gdb/i386-linux-nat.c
@@ -330,7 +330,9 @@  store_fpregs (const struct regcache *regcache, int tid, int regno)
 static int
 fetch_xstateregs (struct regcache *regcache, int tid)
 {
-  char xstateregs[X86_XSTATE_MAX_SIZE];
+  struct gdbarch *gdbarch = regcache->arch ();
+  const i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
+  char xstateregs[tdep->xsave_layout.sizeof_xsave];
   struct iovec iov;
 
   if (have_ptrace_getregset != TRIBOOL_TRUE)
@@ -353,7 +355,9 @@  fetch_xstateregs (struct regcache *regcache, int tid)
 static int
 store_xstateregs (const struct regcache *regcache, int tid, int regno)
 {
-  char xstateregs[X86_XSTATE_MAX_SIZE];
+  struct gdbarch *gdbarch = regcache->arch ();
+  const i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
+  char xstateregs[tdep->xsave_layout.sizeof_xsave];
   struct iovec iov;
 
   if (have_ptrace_getregset != TRIBOOL_TRUE)
diff --git a/gdb/x86-linux-nat.c b/gdb/x86-linux-nat.c
index ca4eaf5b645..cd8fd9c1dcd 100644
--- a/gdb/x86-linux-nat.c
+++ b/gdb/x86-linux-nat.c
@@ -36,6 +36,7 @@ 
 #include "amd64-linux-tdep.h"
 #endif
 #include "gdbsupport/x86-xstate.h"
+#include "nat/x86-xstate.h"
 #include "nat/linux-btrace.h"
 #include "nat/linux-nat.h"
 #include "nat/x86-linux.h"
@@ -179,6 +180,8 @@  x86_linux_nat_target::read_description ()
 	  /* Get XCR0 from XSAVE extended state.  */
 	  xcr0 = xstateregs[(I386_LINUX_XSAVE_XCR0_OFFSET
 			     / sizeof (uint64_t))];
+
+	  m_xsave_layout = x86_fetch_xsave_layout (xcr0, x86_xsave_length ());
 	}
     }
 
diff --git a/gdb/x86-linux-nat.h b/gdb/x86-linux-nat.h
index fcb5f08d251..a99de6c29ea 100644
--- a/gdb/x86-linux-nat.h
+++ b/gdb/x86-linux-nat.h
@@ -22,6 +22,7 @@ 
 
 #include "gdb_proc_service.h"  /* For ps_err_e.  */
 #include "linux-nat.h"
+#include "gdbsupport/x86-xstate.h"
 #include "x86-nat.h"
 #include "nat/x86-linux.h"
 
@@ -41,6 +42,9 @@  struct x86_linux_nat_target : public x86_nat_target<linux_nat_target>
 				 enum btrace_read_type type) override;
   const struct btrace_config *btrace_conf (const struct btrace_target_info *) override;
 
+  x86_xsave_layout fetch_x86_xsave_layout () override
+  { return m_xsave_layout; }
+
   /* These two are rewired to low_ versions.  linux-nat.c queries
      stopped-by-watchpoint info as soon as an lwp stops (via the low_
      methods) and caches the result, to be returned via the normal
@@ -74,6 +78,9 @@  struct x86_linux_nat_target : public x86_nat_target<linux_nat_target>
 protected:
   /* Override the GNU/Linux inferior startup hook.  */
   void post_startup_inferior (ptid_t) override;
+
+private:
+  x86_xsave_layout m_xsave_layout;
 };