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Re: [PATCH V4 4/8] MPX for amd64
- From: Mark Kettenis <mark dot kettenis at xs4all dot nl>
- To: walfred dot tedeschi at intel dot com
- Cc: tromey at redhat dot com, gdb-patches at sourceware dot org, mark dot kettenis at xs4all dot nl, walfred dot tedeschi at intel dot com
- Date: Tue, 10 Sep 2013 14:48:18 +0200 (CEST)
- Subject: Re: [PATCH V4 4/8] MPX for amd64
- Authentication-results: sourceware.org; auth=none
- References: <1378373188-31144-1-git-send-email-walfred dot tedeschi at intel dot com> <1378373188-31144-5-git-send-email-walfred dot tedeschi at intel dot com>
> From: Walfred Tedeschi <walfred.tedeschi@intel.com>
> Date: Thu, 5 Sep 2013 11:26:24 +0200
>
> 2013-06-24 Walfred Tedeschi <walfred.tedeschi@intel.com>
>
> * amd64-linux-nat.c (amd64_linux_gregset32_reg_offset):
> Add MPX registers.
> (amd64_linux_read_description): Add initialization for MPX and
> AVX independently.
> * amd64-linux-tdep.c: Includes features/i386/amd64-mpx-linux.c and
> features/i386/x32-mpx-linux.c.
> (amd64_linux_gregset_reg_offset): Add MPX registers.
> (amd64_linux_core_read_description): Add initialization for MPX
> registers.
> (_initialize_amd64_linux_tdep): Initialize MPX targets.
> * amd64-linux-tdep.h (AMD64_LINUX_NUM_REGS): Set it to the last
> register on the list.
> (tdesc_amd64_mpx_linux and tdesc_x32_mpx_linux) Add new targets
> for MPX.
> * amd64-tdep.c: Includes features/i386/amd64-mpx.c and
> features/i386/x32-mpx.c.
> (amd64_mpx_names): MPX register names.
> (amd64_init_abi): Add MPX register while initializing the ABI.
> (_initialize_amd64_tdep): Initialize MPX targets.
> * amd64-tdep.h (amd64_regnum): Add MPX registers.
> (AMD64_NUM_REGS): Set number of registers taking MPX into account.
>
> ---
> gdb/amd64-linux-nat.c | 43 ++++++++++++++++++++++++++++++++++---------
> gdb/amd64-linux-tdep.c | 14 +++++++++++++-
> gdb/amd64-linux-tdep.h | 6 ++++--
> gdb/amd64-tdep.c | 18 ++++++++++++++++++
> gdb/amd64-tdep.h | 8 ++++++--
> 5 files changed, 75 insertions(+), 14 deletions(-)
>
> diff --git a/gdb/amd64-linux-nat.c b/gdb/amd64-linux-nat.c
> index 8dfe7c5..a230dca 100644
> --- a/gdb/amd64-linux-nat.c
> +++ b/gdb/amd64-linux-nat.c
> @@ -100,7 +100,9 @@ static int amd64_linux_gregset32_reg_offset[] =
> -1, -1, -1, -1, -1, -1, -1, -1,
> -1, -1, -1, -1, -1, -1, -1, -1, -1,
> -1, -1, -1, -1, -1, -1, -1, -1,
> - ORIG_RAX * 8 /* "orig_eax" */
> + ORIG_RAX * 8, /* "orig_eax" */
> + -1, -1, -1, -1, /* MPX registers BND0 ... BND3. */
> + -1, -1 /* MPX registers BNDCFGU, BNDSTATUS. */
> };
This looks wrong to me now that you've kept "orig_eax" at the end.
>
>
> @@ -1094,18 +1096,41 @@ amd64_linux_read_description (struct target_ops *ops)
> }
>
> /* Check the native XCR0 only if PTRACE_GETREGSET is available. */
> - if (have_ptrace_getregset
> - && (xcr0 & I386_XSTATE_AVX_MASK) == I386_XSTATE_AVX_MASK)
> + if (have_ptrace_getregset && (xcr0 & I386_XSTATE_ALL_MASK))
> {
> - if (is_64bit)
> + switch (xcr0 & I386_XSTATE_ALL_MASK)
> {
> - if (is_x32)
> - return tdesc_x32_avx_linux;
> + case I386_XSTATE_MPX_MASK:
> + if (is_64bit)
> + {
> + if (is_x32)
> + return tdesc_x32_mpx_linux;
> + else
> + return tdesc_amd64_mpx_linux;
> + }
> + else
> + return tdesc_i386_mpx_linux;
> + case I386_XSTATE_AVX_MASK:
> + if (is_64bit)
> + {
> + if (is_x32)
> + return tdesc_x32_avx_linux;
> + else
> + return tdesc_amd64_avx_linux;
> + }
> + else
> + return tdesc_i386_avx_linux;
> + default:
> + if (is_64bit)
> + {
> + if (is_x32)
> + return tdesc_x32_linux;
> + else
> + return tdesc_amd64_linux;
> + }
> else
> - return tdesc_amd64_avx_linux;
> + return tdesc_i386_linux;
> }
> - else
> - return tdesc_i386_avx_linux;
> }
> else
> {
> diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
> index 4f67762..9740aff 100644
> --- a/gdb/amd64-linux-tdep.c
> +++ b/gdb/amd64-linux-tdep.c
> @@ -42,8 +42,10 @@
>
> #include "features/i386/amd64-linux.c"
> #include "features/i386/amd64-avx-linux.c"
> +#include "features/i386/amd64-mpx-linux.c"
> #include "features/i386/x32-linux.c"
> #include "features/i386/x32-avx-linux.c"
> +#include "features/i386/x32-mpx-linux.c"
>
> /* The syscall's XML filename for i386. */
> #define XML_SYSCALL_FILENAME_AMD64 "syscalls/amd64-linux.xml"
> @@ -96,6 +98,8 @@ int amd64_linux_gregset_reg_offset[] =
> -1, -1, -1, -1, -1, -1, -1, -1, -1,
> -1, -1, -1, -1, -1, -1, -1, -1,
> -1, -1, -1, -1, -1, -1, -1, -1,
> + -1, -1, -1, -1, /* MPX registers BND0 ... BND3. */
> + -1, -1, /* MPX registers BNDCFGU and BNDSTATUS. */
> 15 * 8 /* "orig_rax" */
> };
>
> @@ -1287,8 +1291,14 @@ amd64_linux_core_read_description (struct gdbarch *gdbarch,
> {
> /* Linux/x86-64. */
> uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd);
> - switch ((xcr0 & I386_XSTATE_AVX_MASK))
> +
> + switch (xcr0 & I386_XSTATE_ALL_MASK)
> {
> + case I386_XSTATE_MPX_MASK:
> + if (gdbarch_ptr_bit (gdbarch) == 32)
> + return tdesc_x32_mpx_linux;
> + else
> + return tdesc_amd64_mpx_linux;
> case I386_XSTATE_AVX_MASK:
> if (gdbarch_ptr_bit (gdbarch) == 32)
> return tdesc_x32_avx_linux;
> @@ -1623,6 +1633,8 @@ _initialize_amd64_linux_tdep (void)
> /* Initialize the Linux target description. */
> initialize_tdesc_amd64_linux ();
> initialize_tdesc_amd64_avx_linux ();
> + initialize_tdesc_amd64_mpx_linux ();
> initialize_tdesc_x32_linux ();
> initialize_tdesc_x32_avx_linux ();
> + initialize_tdesc_x32_mpx_linux ();
> }
> diff --git a/gdb/amd64-linux-tdep.h b/gdb/amd64-linux-tdep.h
> index e9eaeaa..ec10b7c 100644
> --- a/gdb/amd64-linux-tdep.h
> +++ b/gdb/amd64-linux-tdep.h
> @@ -26,16 +26,18 @@
> /* Register number for the "orig_rax" register. If this register
> contains a value >= 0 it is interpreted as the system call number
> that the kernel is supposed to restart. */
> -#define AMD64_LINUX_ORIG_RAX_REGNUM (AMD64_YMM15H_REGNUM + 1)
> +#define AMD64_LINUX_ORIG_RAX_REGNUM (AMD64_BNDSTATUS_REGNUM + 1)
>
> /* Total number of registers for GNU/Linux. */
> -#define AMD64_LINUX_NUM_REGS (AMD64_LINUX_ORIG_RAX_REGNUM + 1)
> +#define AMD64_LINUX_NUM_REGS (AMD64_BNDSTATUS_REGNUM + 2)
>
> /* Linux target description. */
> extern struct target_desc *tdesc_amd64_linux;
> extern struct target_desc *tdesc_amd64_avx_linux;
> +extern struct target_desc *tdesc_amd64_mpx_linux;
> extern struct target_desc *tdesc_x32_linux;
> extern struct target_desc *tdesc_x32_avx_linux;
> +extern struct target_desc *tdesc_x32_mpx_linux;
>
> /* Enum that defines the syscall identifiers for amd64 linux.
> Used for process record/replay, these will be translated into
> diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
> index 3ab74f0..f0654ba 100644
> --- a/gdb/amd64-tdep.c
> +++ b/gdb/amd64-tdep.c
> @@ -43,8 +43,10 @@
>
> #include "features/i386/amd64.c"
> #include "features/i386/amd64-avx.c"
> +#include "features/i386/amd64-mpx.c"
> #include "features/i386/x32.c"
> #include "features/i386/x32-avx.c"
> +#include "features/i386/x32-mpx.c"
>
> #include "ax.h"
> #include "ax-gdb.h"
> @@ -92,6 +94,11 @@ static const char *amd64_ymmh_names[] =
> "ymm12h", "ymm13h", "ymm14h", "ymm15h"
> };
>
> +static const char *amd64_mpx_names[] =
> +{
> + "bnd0raw", "bnd1raw", "bnd2raw", "bnd3raw", "bndcfgu", "bndstatus"
> +};
I'm not convinced the way you're treating the bounds registers makes
all that much sense. I think bnd0-bnd3 should contain the "raw"
128-bit value. But I'm a low-level guy.
> +
> /* The registers used to pass integer arguments during a function call. */
> static int amd64_dummy_call_integer_regs[] =
> {
> @@ -2870,6 +2877,15 @@ amd64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> tdep->ymm0h_regnum = AMD64_YMM0H_REGNUM;
> }
>
> + if (tdesc_find_feature (tdesc, "org.gnu.gdb.i386.mpx") != NULL)
> + {
> + tdep->mpx_register_names = amd64_mpx_names;
> + tdep->num_mpx_regs = AMD64_BNDSTATUS_REGNUM - AMD64_BND0R_REGNUM + 1;
> + tdep->bndcfgu_regnum = AMD64_BNDCFGU_REGNUM;
> + tdep->bnd0r_regnum = AMD64_BND0R_REGNUM;
> + tdep->num_bnd_regs = 4;
> + }
Is the number of bounds registers going to change between 32-bit and
64-bit mode? Otherwise, I think you could (and should) reduce the
number of new "struct gdbarch_tdep" members.