From b42405a159450004f2e2497e2b2d81bcac85c947 Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Mon, 28 Aug 2023 14:18:19 -0700 Subject: [PATCH] gdb: Update x86 Linux architectures to support XSAVE layouts. Refactor i386_linux_core_read_xcr0 to fetch and return a corresponding x86_xsave_layout as well as xcr0 using the size of an existing NT_X86_XSTATE core dump to determine the offsets via i387_guess_xsave_layout. Use this to add an implementation of gdbarch_core_xfer_x86_xsave_layout. Use tdep->xsave_layout.sizeof_xsave as the size of the XSTATE register set. Approved-By: Simon Marchi --- gdb/amd64-linux-tdep.c | 13 +++++++-- gdb/i386-linux-tdep.c | 66 +++++++++++++++++++++++------------------- gdb/i386-linux-tdep.h | 25 +++++++++------- 3 files changed, 61 insertions(+), 43 deletions(-) diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c index cbbac1a0c64..e2fdf5fb6c8 100644 --- a/gdb/amd64-linux-tdep.c +++ b/gdb/amd64-linux-tdep.c @@ -1616,7 +1616,10 @@ amd64_linux_core_read_description (struct gdbarch *gdbarch, bfd *abfd) { /* Linux/x86-64. */ - uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd); + x86_xsave_layout layout; + uint64_t xcr0 = i386_linux_core_read_xsave_info (abfd, layout); + if (xcr0 == 0) + xcr0 = X86_XSTATE_SSE_MASK; return amd64_linux_read_description (xcr0 & X86_XSTATE_ALL_MASK, gdbarch_ptr_bit (gdbarch) == 32); @@ -1661,8 +1664,10 @@ amd64_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, cb (".reg", 27 * 8, 27 * 8, &i386_gregset, NULL, cb_data); cb (".reg2", 512, 512, &amd64_fpregset, NULL, cb_data); - cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0), X86_XSTATE_SIZE (tdep->xcr0), - &amd64_linux_xstateregset, "XSAVE extended state", cb_data); + if (tdep->xsave_layout.sizeof_xsave != 0) + cb (".reg-xstate", tdep->xsave_layout.sizeof_xsave, + tdep->xsave_layout.sizeof_xsave, &amd64_linux_xstateregset, + "XSAVE extended state", cb_data); } /* The instruction sequences used in x86_64 machines for a @@ -1804,6 +1809,8 @@ amd64_linux_init_abi_common(struct gdbarch_info info, struct gdbarch *gdbarch, tdep->sc_num_regs = ARRAY_SIZE (amd64_linux_sc_reg_offset); tdep->xsave_xcr0_offset = I386_LINUX_XSAVE_XCR0_OFFSET; + set_gdbarch_core_read_x86_xsave_layout + (gdbarch, i386_linux_core_read_x86_xsave_layout); /* Add the %orig_rax register used for syscall restarting. */ set_gdbarch_write_pc (gdbarch, amd64_linux_write_pc); diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c index 554c1455a5f..7ff7c155e2c 100644 --- a/gdb/i386-linux-tdep.c +++ b/gdb/i386-linux-tdep.c @@ -638,45 +638,48 @@ static int i386_linux_sc_reg_offset[] = 0 * 4 /* %gs */ }; -/* Get XSAVE extended state xcr0 from core dump. */ +/* See i386-linux-tdep.h. */ uint64_t -i386_linux_core_read_xcr0 (bfd *abfd) +i386_linux_core_read_xsave_info (bfd *abfd, x86_xsave_layout &layout) { asection *xstate = bfd_get_section_by_name (abfd, ".reg-xstate"); - uint64_t xcr0; + if (xstate == nullptr) + return 0; - if (xstate) - { - size_t size = bfd_section_size (xstate); + /* Check extended state size. */ + size_t size = bfd_section_size (xstate); + if (size < X86_XSTATE_AVX_SIZE) + return 0; - /* Check extended state size. */ - if (size < X86_XSTATE_AVX_SIZE) - xcr0 = X86_XSTATE_SSE_MASK; - else - { - char contents[8]; - - if (! bfd_get_section_contents (abfd, xstate, contents, - I386_LINUX_XSAVE_XCR0_OFFSET, - 8)) - { - warning (_("Couldn't read `xcr0' bytes from " - "`.reg-xstate' section in core file.")); - return 0; - } - - xcr0 = bfd_get_64 (abfd, contents); - } + char contents[8]; + if (! bfd_get_section_contents (abfd, xstate, contents, + I386_LINUX_XSAVE_XCR0_OFFSET, 8)) + { + warning (_("Couldn't read `xcr0' bytes from " + "`.reg-xstate' section in core file.")); + return 0; } - else - xcr0 = 0; + + uint64_t xcr0 = bfd_get_64 (abfd, contents); + + if (!i387_guess_xsave_layout (xcr0, size, layout)) + return 0; return xcr0; } /* See i386-linux-tdep.h. */ +bool +i386_linux_core_read_x86_xsave_layout (struct gdbarch *gdbarch, + x86_xsave_layout &layout) +{ + return i386_linux_core_read_xsave_info (core_bfd, layout) != 0; +} + +/* See i386-linux-tdep.h. */ + const struct target_desc * i386_linux_read_description (uint64_t xcr0) { @@ -708,7 +711,8 @@ i386_linux_core_read_description (struct gdbarch *gdbarch, bfd *abfd) { /* Linux/i386. */ - uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd); + x86_xsave_layout layout; + uint64_t xcr0 = i386_linux_core_read_xsave_info (abfd, layout); const struct target_desc *tdesc = i386_linux_read_description (xcr0); if (tdesc != NULL) @@ -767,9 +771,9 @@ i386_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, cb (".reg", 68, 68, &i386_gregset, NULL, cb_data); - if (tdep->xcr0 & X86_XSTATE_AVX) - cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0), - X86_XSTATE_SIZE (tdep->xcr0), &i386_linux_xstateregset, + if (tdep->xsave_layout.sizeof_xsave != 0) + cb (".reg-xstate", tdep->xsave_layout.sizeof_xsave, + tdep->xsave_layout.sizeof_xsave, &i386_linux_xstateregset, "XSAVE extended state", cb_data); else if (tdep->xcr0 & X86_XSTATE_SSE) cb (".reg-xfp", 512, 512, &i386_fpregset, "extended floating-point", @@ -872,6 +876,8 @@ i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) tdep->sc_num_regs = ARRAY_SIZE (i386_linux_sc_reg_offset); tdep->xsave_xcr0_offset = I386_LINUX_XSAVE_XCR0_OFFSET; + set_gdbarch_core_read_x86_xsave_layout + (gdbarch, i386_linux_core_read_x86_xsave_layout); set_gdbarch_process_record (gdbarch, i386_process_record); set_gdbarch_process_record_signal (gdbarch, i386_linux_record_signal); diff --git a/gdb/i386-linux-tdep.h b/gdb/i386-linux-tdep.h index c0fd1f7f300..bd8e328b7fe 100644 --- a/gdb/i386-linux-tdep.h +++ b/gdb/i386-linux-tdep.h @@ -20,6 +20,8 @@ #ifndef I386_LINUX_TDEP_H #define I386_LINUX_TDEP_H +#include "gdbsupport/x86-xstate.h" + /* The Linux kernel pretends there is an additional "orig_eax" register. Since GDB needs access to that register to be able to properly restart system calls when necessary (see @@ -34,8 +36,18 @@ /* Total number of registers for GNU/Linux. */ #define I386_LINUX_NUM_REGS (I386_LINUX_ORIG_EAX_REGNUM + 1) -/* Get XSAVE extended state xcr0 from core dump. */ -extern uint64_t i386_linux_core_read_xcr0 (bfd *abfd); +/* Read the XSAVE extended state xcr0 value from the ABFD core file. + If it appears to be valid, return it and fill LAYOUT with values + inferred from that value. + + Otherwise, return 0 to indicate no state was found and leave LAYOUT + untouched. */ +extern uint64_t i386_linux_core_read_xsave_info (bfd *abfd, + x86_xsave_layout &layout); + +/* Implement the core_read_x86_xsave_layout gdbarch method. */ +extern bool i386_linux_core_read_x86_xsave_layout (struct gdbarch *gdbarch, + x86_xsave_layout &layout); /* Handle and display information related to the MPX bound violation to the user. */ @@ -52,14 +64,7 @@ extern const struct target_desc *i386_linux_read_description (uint64_t xcr0); fxsave_bytes[0..463] sw_usable_bytes[464..511] xstate_hdr_bytes[512..575] - avx_bytes[576..831] - mpx_bytes [960..1032] - avx512_k_regs[1088..1152] - avx512_zmmh_regs0-7[1153..1407] - avx512_zmmh_regs8-15[1408..1663] - avx512_zmm_regs16-31[1664..2687] - pkru[2688..2752] - future_state etc + extended state regions (AVX, MPX, AVX512, PKRU, etc.) }; Same memory layout will be used for the coredump NT_X86_XSTATE -- 2.30.2