mirror of git://sourceware.org/git/glibc.git
elf: Add SFrame stack tracing
This patch adds the necessary bits to enable stack tracing using SFrame. In the case the new SFrame stack tracing procedure doesn't find SFrame related info, the stack tracing falls back on default Dwarf implementation. The new SFrame stack tracing procedure is added to debug/backtrace.c file, the support functions are added in sysdeps folder, namely sframe.h, read-sframe.c and read-sfame.h. Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com> Reviewed-by: DJ Delorie <dj@redhat.com>
This commit is contained in:
Claudiu Zissulescu
Sam James
parent
b231c21fc6
commit
3360913c37
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@ -20,6 +20,7 @@
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#include <stdlib.h>
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#include <unwind.h>
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#include <unwind-link.h>
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#include <sframe.h>
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struct trace_arg
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{
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@ -30,6 +31,40 @@ struct trace_arg
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int size;
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};
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/* Initialize the SFrame backtrace routine and attempt to backtrace
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the current stack using SFrame information. For the SFrame
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backtrace to be considered valid, the tracer must return more than
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one frame. If it doesn't, this could indicate a mixed
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environment for example, glibc may have been compiled with SFrame
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support, while the application was not. An even more complex
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scenario arises when the application uses shared objects compiled
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with differing configurations.
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Additionally, glibc includes certain callback paths that must be
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considered. For example: an application calls shared object A,
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which calls shared object B, which in turn calls qsort() in
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glibc. qsort() then invokes a helper in shared object C, which
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raises a SIGFPE signal, handled by object D, which requests a
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backtrace. Any of these components may or may not include SFrame
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encoding.
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In cases where a stack frame lacks SFrame information, the SFrame
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backtracer can fall back to using the DWARF unwinder.
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This function must be always inline. Otherwise the
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__builtin_frame_address and the __getXX helper functions will not
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return the right addresses. */
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static inline int __attribute__ ((always_inline))
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do_sframe_backtrace (void **array, int size)
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{
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frame frame;
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frame.pc = __getPC ();
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frame.sp = __getSP ();
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frame.fp = (_Unwind_Ptr) __builtin_frame_address (0);
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return __stacktrace_sframe (array, size, &frame);
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}
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static _Unwind_Reason_Code
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backtrace_helper (struct _Unwind_Context *ctx, void *a)
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{
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@ -72,7 +107,16 @@ __backtrace (void **array, int size)
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.cnt = -1
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};
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if (size <= 0 || arg.unwind_link == NULL)
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if (size <= 0)
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return 0;
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/* Try first the SFrame backtracer. */
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int cnt = do_sframe_backtrace (array, size);
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if (cnt > 1)
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return cnt;
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/* Try the dwarf unwinder. */
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if (arg.unwind_link == NULL)
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return 0;
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UNWIND_LINK_PTR (arg.unwind_link, _Unwind_Backtrace)
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@ -21,6 +21,7 @@ CFLAGS-wordcopy.c += -Wno-uninitialized
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endif
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ifeq ($(subdir),elf)
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sysdep_routines += sframe-read sframe
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ifeq (yes:yes,$(build-shared):$(unwind-find-fde))
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# This is needed to support g++ v2 and v3.
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sysdep_routines += framestate unwind-pe
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@ -0,0 +1,566 @@
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/* Copyright (C) 2025 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include <string.h>
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#include <assert.h>
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#include <sframe-read.h>
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/* Get the SFrame header size. */
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static inline uint32_t
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sframe_get_hdr_size (sframe_header *sfh)
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{
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return SFRAME_V1_HDR_SIZE (*sfh);
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}
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/* Access functions for frame row entry data. */
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static inline uint8_t
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sframe_fre_get_offset_count (uint8_t fre_info)
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{
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return SFRAME_V1_FRE_OFFSET_COUNT (fre_info);
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}
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static inline uint8_t
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sframe_fre_get_offset_size (uint8_t fre_info)
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{
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return SFRAME_V1_FRE_OFFSET_SIZE (fre_info);
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}
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static inline bool
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sframe_get_fre_ra_mangled_p (uint8_t fre_info)
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{
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return SFRAME_V1_FRE_MANGLED_RA_P (fre_info);
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}
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/* Access functions for info from function descriptor entry. */
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static uint32_t
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sframe_get_fre_type (sframe_func_desc_entry *fdep)
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{
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uint32_t fre_type = 0;
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if (fdep != NULL)
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fre_type = SFRAME_V1_FUNC_FRE_TYPE (fdep->sfde_func_info);
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return fre_type;
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}
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static uint32_t
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sframe_get_fde_type (sframe_func_desc_entry *fdep)
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{
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uint32_t fde_type = 0;
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if (fdep != NULL)
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fde_type = SFRAME_V1_FUNC_FDE_TYPE (fdep->sfde_func_info);
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return fde_type;
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}
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/* Check if SFrame header has valid data. Only consider SFrame type
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2. */
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static bool
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sframe_header_sanity_check_p (sframe_header *hp)
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{
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uint8_t all_flags = SFRAME_F_FDE_SORTED | SFRAME_F_FRAME_POINTER;
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/* Check preamble is valid. */
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if ((hp->sfh_preamble.sfp_magic != SFRAME_MAGIC)
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|| (hp->sfh_preamble.sfp_version != SFRAME_VERSION_2)
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|| ((hp->sfh_preamble.sfp_flags | all_flags) != all_flags))
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return false;
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/* Check offsets are valid. */
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if (hp->sfh_fdeoff > hp->sfh_freoff)
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return false;
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return true;
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}
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/* Get the FRE start address size. */
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static size_t
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sframe_fre_start_addr_size (uint32_t fre_type)
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{
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size_t addr_size = 0;
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switch (fre_type)
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{
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case SFRAME_FRE_TYPE_ADDR1:
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addr_size = 1;
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break;
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case SFRAME_FRE_TYPE_ADDR2:
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addr_size = 2;
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break;
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case SFRAME_FRE_TYPE_ADDR4:
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addr_size = 4;
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break;
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default:
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break;
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}
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return addr_size;
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}
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/* Check if the FREP has valid data. */
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static bool
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sframe_fre_sanity_check_p (sframe_frame_row_entry *frep)
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{
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uint8_t offset_size, offset_cnt;
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uint8_t fre_info;
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if (frep == NULL)
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return false;
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fre_info = frep->fre_info;
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offset_size = sframe_fre_get_offset_size (fre_info);
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if (offset_size != SFRAME_FRE_OFFSET_1B
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&& offset_size != SFRAME_FRE_OFFSET_2B
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&& offset_size != SFRAME_FRE_OFFSET_4B)
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return false;
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offset_cnt = sframe_fre_get_offset_count (fre_info);
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if (offset_cnt > MAX_NUM_STACK_OFFSETS)
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return false;
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return true;
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}
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/* Get FRE_INFO's offset size in bytes. */
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static size_t
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sframe_fre_offset_bytes_size (uint8_t fre_info)
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{
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uint8_t offset_size, offset_cnt;
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offset_size = sframe_fre_get_offset_size (fre_info);
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offset_cnt = sframe_fre_get_offset_count (fre_info);
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if (offset_size == SFRAME_FRE_OFFSET_2B
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|| offset_size == SFRAME_FRE_OFFSET_4B) /* 2 or 4 bytes. */
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return (offset_cnt * (offset_size * 2));
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return (offset_cnt);
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}
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/* Get total size in bytes to represent FREP in the binary format. This
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includes the starting address, FRE info, and all the offsets. */
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static size_t
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sframe_fre_entry_size (sframe_frame_row_entry *frep, size_t addr_size)
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{
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if (frep == NULL)
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return 0;
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uint8_t fre_info = frep->fre_info;
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return (addr_size + sizeof (frep->fre_info)
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+ sframe_fre_offset_bytes_size (fre_info));
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}
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/* Check whether for the given FDEP, the SFrame Frame Row Entry identified via
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the START_IP_OFFSET and the END_IP_OFFSET, provides the stack trace
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information for the PC. */
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static bool
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sframe_fre_check_range_p (sframe_func_desc_entry *fdep,
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uint32_t start_ip_offset, uint32_t end_ip_offset,
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int32_t pc)
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{
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int32_t func_start_addr;
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uint8_t rep_block_size;
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uint32_t fde_type;
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uint32_t pc_offset;
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bool mask_p;
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if (fdep == NULL)
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return false;
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func_start_addr = fdep->sfde_func_start_address;
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fde_type = sframe_get_fde_type (fdep);
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mask_p = (fde_type == SFRAME_FDE_TYPE_PCMASK);
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rep_block_size = fdep->sfde_func_rep_size;
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if (func_start_addr > pc)
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return false;
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/* Given func_start_addr <= pc, pc - func_start_addr must be positive. */
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pc_offset = pc - func_start_addr;
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/* For SFrame FDEs encoding information for repetitive pattern of insns,
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masking with the rep_block_size is necessary to find the matching FRE. */
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if (mask_p)
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pc_offset = pc_offset % rep_block_size;
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return (start_ip_offset <= pc_offset) && (end_ip_offset >= pc_offset);
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}
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/* The SFrame Decoder. */
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/* Get SFrame header from the given decoder context DCTX. */
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static inline sframe_header *
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sframe_decoder_get_header (sframe_decoder_ctx *dctx)
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{
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sframe_header *hp = NULL;
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if (dctx != NULL)
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hp = &dctx->sfd_header;
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return hp;
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}
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/* Get IDX'th offset from FRE. Set ERRP as applicable. */
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static int32_t
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sframe_get_fre_offset (sframe_frame_row_entry *fre,
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int idx,
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_Unwind_Reason_Code *errp)
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{
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uint8_t offset_cnt, offset_size;
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if (!sframe_fre_sanity_check_p (fre))
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{
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*errp = _URC_END_OF_STACK;
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return 0;
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}
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offset_cnt = sframe_fre_get_offset_count (fre->fre_info);
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offset_size = sframe_fre_get_offset_size (fre->fre_info);
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if (offset_cnt < (idx + 1))
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{
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*errp = _URC_END_OF_STACK;
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return 0;
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}
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*errp = _URC_NO_REASON;
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if (offset_size == SFRAME_FRE_OFFSET_1B)
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{
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int8_t *sp = (int8_t *)fre->fre_offsets;
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return sp[idx];
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}
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else if (offset_size == SFRAME_FRE_OFFSET_2B)
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{
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int16_t *sp = (int16_t *)fre->fre_offsets;
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return sp[idx];
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}
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else
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{
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int32_t *ip = (int32_t *)fre->fre_offsets;
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return ip[idx];
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}
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}
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/* Decode the SFrame FRE start address offset value from FRE_BUF in on-disk
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binary format, given the FRE_TYPE. Updates the FRE_START_ADDR. */
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static void
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sframe_decode_fre_start_address (const char *fre_buf,
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uint32_t *fre_start_addr,
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uint32_t fre_type)
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{
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uint32_t saddr = 0;
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if (fre_type == SFRAME_FRE_TYPE_ADDR1)
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{
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uint8_t *uc = (uint8_t *)fre_buf;
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saddr = (uint32_t)*uc;
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}
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else if (fre_type == SFRAME_FRE_TYPE_ADDR2)
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{
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uint16_t *ust = (uint16_t *)fre_buf;
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saddr = (uint32_t)*ust;
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}
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else if (fre_type == SFRAME_FRE_TYPE_ADDR4)
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{
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uint32_t *uit = (uint32_t *)fre_buf;
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saddr = (uint32_t)*uit;
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}
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else
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return;
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*fre_start_addr = saddr;
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}
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/* Find the function descriptor entry starting which contains the specified
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address ADDR. */
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static sframe_func_desc_entry *
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sframe_get_funcdesc_with_addr_internal (sframe_decoder_ctx *ctx, int32_t addr,
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int *errp)
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{
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sframe_header *dhp;
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sframe_func_desc_entry *fdp;
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int low, high;
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if (ctx == NULL)
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return NULL;
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dhp = sframe_decoder_get_header (ctx);
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if (dhp == NULL || dhp->sfh_num_fdes == 0 || ctx->sfd_funcdesc == NULL)
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return NULL;
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/* If the FDE sub-section is not sorted on PCs, skip the lookup because
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binary search cannot be used. */
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if ((dhp->sfh_preamble.sfp_flags & SFRAME_F_FDE_SORTED) == 0)
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return NULL;
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/* Do the binary search. */
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fdp = (sframe_func_desc_entry *) ctx->sfd_funcdesc;
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low = 0;
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high = dhp->sfh_num_fdes;
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while (low <= high)
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{
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int mid = low + (high - low) / 2;
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/* Given sfde_func_start_address <= addr,
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addr - sfde_func_start_address must be positive. */
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if (fdp[mid].sfde_func_start_address <= addr
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&& ((uint32_t)(addr - fdp[mid].sfde_func_start_address)
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< fdp[mid].sfde_func_size))
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return fdp + mid;
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if (fdp[mid].sfde_func_start_address < addr)
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low = mid + 1;
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else
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high = mid - 1;
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}
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return NULL;
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}
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/* Get the end IP offset for the FRE at index i in the FDEP. The buffer FRES
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is the starting location for the FRE. */
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static uint32_t
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sframe_fre_get_end_ip_offset (sframe_func_desc_entry *fdep, unsigned int i,
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const char *fres)
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{
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uint32_t end_ip_offset = 0;
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uint32_t fre_type;
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fre_type = sframe_get_fre_type (fdep);
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/* Get the start address of the next FRE in sequence. */
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if (i < fdep->sfde_func_num_fres - 1)
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{
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sframe_decode_fre_start_address (fres, &end_ip_offset, fre_type);
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end_ip_offset -= 1;
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}
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else
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/* The end IP offset for the FRE needs to be deduced from the function
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size. */
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end_ip_offset = fdep->sfde_func_size - 1;
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return end_ip_offset;
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}
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/* Get the SFrame's fixed FP offset given the decoder context CTX. */
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static int8_t
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sframe_decoder_get_fixed_fp_offset (sframe_decoder_ctx *ctx)
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{
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sframe_header *dhp;
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dhp = sframe_decoder_get_header (ctx);
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return dhp->sfh_cfa_fixed_fp_offset;
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}
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/* Get the SFrame's fixed RA offset given the decoder context CTX. */
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static int8_t
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sframe_decoder_get_fixed_ra_offset (sframe_decoder_ctx *ctx)
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{
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sframe_header *dhp;
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dhp = sframe_decoder_get_header (ctx);
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return dhp->sfh_cfa_fixed_ra_offset;
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}
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/* Get the base reg id from the FRE info. Set errp if failure. */
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uint8_t
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__sframe_fre_get_base_reg_id (sframe_frame_row_entry *fre)
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{
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uint8_t fre_info = fre->fre_info;
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return SFRAME_V1_FRE_CFA_BASE_REG_ID (fre_info);
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}
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|
||||
/* Get the CFA offset from the FRE. If the offset is unavailable,
|
||||
sets errp. */
|
||||
|
||||
int32_t
|
||||
__sframe_fre_get_cfa_offset (sframe_decoder_ctx *dctx __attribute__ ((__unused__)),
|
||||
sframe_frame_row_entry *fre,
|
||||
_Unwind_Reason_Code *errp)
|
||||
{
|
||||
return sframe_get_fre_offset (fre, SFRAME_FRE_CFA_OFFSET_IDX, errp);
|
||||
}
|
||||
|
||||
/* Get the FP offset from the FRE. If the offset is unavailable, sets
|
||||
errp. */
|
||||
|
||||
int32_t
|
||||
__sframe_fre_get_fp_offset (sframe_decoder_ctx *dctx,
|
||||
sframe_frame_row_entry *fre,
|
||||
_Unwind_Reason_Code *errp)
|
||||
{
|
||||
uint32_t fp_offset_idx = 0;
|
||||
int8_t fp_offset = sframe_decoder_get_fixed_fp_offset (dctx);
|
||||
|
||||
*errp = _URC_NO_REASON;
|
||||
/* If the FP offset is not being tracked, return the fixed FP offset
|
||||
from the SFrame header. */
|
||||
if (fp_offset != SFRAME_CFA_FIXED_FP_INVALID)
|
||||
return fp_offset;
|
||||
|
||||
/* In some ABIs, the stack offset to recover RA (using the CFA) from is
|
||||
fixed (like AMD64). In such cases, the stack offset to recover FP will
|
||||
appear at the second index. */
|
||||
fp_offset_idx = ((sframe_decoder_get_fixed_ra_offset (dctx)
|
||||
!= SFRAME_CFA_FIXED_RA_INVALID)
|
||||
? SFRAME_FRE_RA_OFFSET_IDX
|
||||
: SFRAME_FRE_FP_OFFSET_IDX);
|
||||
return sframe_get_fre_offset (fre, fp_offset_idx, errp);
|
||||
}
|
||||
|
||||
/* Get the RA offset from the FRE. If the offset is unavailable, sets
|
||||
errp. */
|
||||
|
||||
int32_t
|
||||
__sframe_fre_get_ra_offset (sframe_decoder_ctx *dctx,
|
||||
sframe_frame_row_entry *fre,
|
||||
_Unwind_Reason_Code *errp)
|
||||
{
|
||||
int8_t ra_offset = sframe_decoder_get_fixed_ra_offset (dctx);
|
||||
*errp = _URC_NO_REASON;
|
||||
|
||||
/* If the RA offset was not being tracked, return the fixed RA offset
|
||||
from the SFrame header. */
|
||||
if (ra_offset != SFRAME_CFA_FIXED_RA_INVALID)
|
||||
return ra_offset;
|
||||
|
||||
/* Otherwise, get the RA offset from the FRE. */
|
||||
return sframe_get_fre_offset (fre, SFRAME_FRE_RA_OFFSET_IDX, errp);
|
||||
}
|
||||
|
||||
/* Decode the specified SFrame buffer SF_BUF and return the new SFrame
|
||||
decoder context. */
|
||||
|
||||
_Unwind_Reason_Code
|
||||
__sframe_decode (sframe_decoder_ctx *dctx, const char *sf_buf)
|
||||
{
|
||||
const sframe_preamble *sfp;
|
||||
size_t hdrsz;
|
||||
sframe_header *sfheaderp;
|
||||
char *frame_buf;
|
||||
|
||||
int fidx_size;
|
||||
uint32_t fre_bytes;
|
||||
|
||||
if (sf_buf == NULL)
|
||||
return _URC_END_OF_STACK;
|
||||
|
||||
sfp = (const sframe_preamble *) sf_buf;
|
||||
|
||||
/* Check for foreign endianness. */
|
||||
if (sfp->sfp_magic != SFRAME_MAGIC)
|
||||
return _URC_END_OF_STACK;
|
||||
|
||||
frame_buf = (char *)sf_buf;
|
||||
|
||||
/* Handle the SFrame header. */
|
||||
dctx->sfd_header = *(sframe_header *) frame_buf;
|
||||
|
||||
/* Validate the contents of SFrame header. */
|
||||
sfheaderp = &dctx->sfd_header;
|
||||
if (!sframe_header_sanity_check_p (sfheaderp))
|
||||
return _URC_END_OF_STACK;
|
||||
|
||||
hdrsz = sframe_get_hdr_size (sfheaderp);
|
||||
frame_buf += hdrsz;
|
||||
|
||||
/* Handle the SFrame Function Descriptor Entry section. */
|
||||
fidx_size
|
||||
= sfheaderp->sfh_num_fdes * sizeof (sframe_func_desc_entry);
|
||||
dctx->sfd_funcdesc = (sframe_func_desc_entry *)frame_buf;
|
||||
frame_buf += (fidx_size);
|
||||
|
||||
dctx->sfd_fres = frame_buf;
|
||||
fre_bytes = sfheaderp->sfh_fre_len;
|
||||
dctx->sfd_fre_nbytes = fre_bytes;
|
||||
|
||||
return _URC_NO_REASON;
|
||||
}
|
||||
|
||||
/* Find the SFrame Row Entry which contains the PC. Returns
|
||||
_URC_END_OF_STACK if failure. */
|
||||
|
||||
_Unwind_Reason_Code
|
||||
__sframe_find_fre (sframe_decoder_ctx *ctx, int32_t pc,
|
||||
sframe_frame_row_entry *frep)
|
||||
{
|
||||
sframe_func_desc_entry *fdep;
|
||||
uint32_t fre_type, i;
|
||||
uint32_t start_ip_offset;
|
||||
int32_t func_start_addr;
|
||||
uint32_t end_ip_offset;
|
||||
const char *fres;
|
||||
size_t size = 0;
|
||||
int err = 0;
|
||||
|
||||
if ((ctx == NULL) || (frep == NULL))
|
||||
return _URC_END_OF_STACK;
|
||||
|
||||
/* Find the FDE which contains the PC, then scan its fre entries. */
|
||||
fdep = sframe_get_funcdesc_with_addr_internal (ctx, pc, &err);
|
||||
if (fdep == NULL || ctx->sfd_fres == NULL)
|
||||
return _URC_END_OF_STACK;
|
||||
|
||||
fre_type = sframe_get_fre_type (fdep);
|
||||
|
||||
fres = ctx->sfd_fres + fdep->sfde_func_start_fre_off;
|
||||
func_start_addr = fdep->sfde_func_start_address;
|
||||
|
||||
for (i = 0; i < fdep->sfde_func_num_fres; i++)
|
||||
{
|
||||
size_t addr_size;
|
||||
|
||||
/* Partially decode the FRE. */
|
||||
sframe_decode_fre_start_address (fres, &frep->fre_start_addr, fre_type);
|
||||
|
||||
addr_size = sframe_fre_start_addr_size (fre_type);
|
||||
if (addr_size == 0)
|
||||
return _URC_END_OF_STACK;
|
||||
|
||||
frep->fre_info = *(uint8_t *)(fres + addr_size);
|
||||
size = sframe_fre_entry_size (frep, addr_size);
|
||||
|
||||
start_ip_offset = frep->fre_start_addr;
|
||||
end_ip_offset = sframe_fre_get_end_ip_offset (fdep, i, fres + size);
|
||||
|
||||
/* Stop search if FRE's start_ip is greater than pc. Given
|
||||
func_start_addr <= pc, pc - func_start_addr must be positive. */
|
||||
if (start_ip_offset > (uint32_t) (pc - func_start_addr))
|
||||
return _URC_END_OF_STACK;
|
||||
|
||||
if (sframe_fre_check_range_p (fdep, start_ip_offset, end_ip_offset, pc))
|
||||
{
|
||||
/* Decode last FRE bits: offsets size. */
|
||||
frep->fre_offsets = fres + addr_size + sizeof (frep->fre_info);
|
||||
return _URC_NO_REASON;
|
||||
}
|
||||
|
||||
fres += size;
|
||||
}
|
||||
return _URC_END_OF_STACK;
|
||||
}
|
||||
|
|
@ -0,0 +1,106 @@
|
|||
/* Copyright (C) 2025 Free Software Foundation, Inc.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
The GNU C Library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the GNU Lesser General Public License as
|
||||
published by the Free Software Foundation; either version 2.1 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
The GNU C Library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||||
|
||||
#ifndef _SFRAME_API_H
|
||||
#define _SFRAME_API_H
|
||||
|
||||
#include <sframe.h>
|
||||
#include <stdbool.h>
|
||||
#include <unwind.h>
|
||||
|
||||
#ifdef __cplusplus
|
||||
extern "C"
|
||||
{
|
||||
#endif
|
||||
|
||||
typedef struct sframe_decoder_ctx
|
||||
{
|
||||
|
||||
sframe_header sfd_header;
|
||||
|
||||
sframe_func_desc_entry *sfd_funcdesc;
|
||||
/* SFrame FRE table. */
|
||||
char *sfd_fres;
|
||||
/* Number of bytes needed for SFrame FREs. */
|
||||
int sfd_fre_nbytes;
|
||||
} sframe_decoder_ctx;
|
||||
|
||||
#define MAX_NUM_STACK_OFFSETS 3
|
||||
|
||||
/* User interfacing SFrame Row Entry.
|
||||
An abstraction provided by libsframe so the consumer is decoupled from
|
||||
the binary format representation of the same.
|
||||
|
||||
The members are best ordered such that they are aligned at their natural
|
||||
boundaries. This helps avoid usage of undesirable misaligned memory
|
||||
accesses. See PR libsframe/29856. */
|
||||
|
||||
typedef struct sframe_frame_row_entry
|
||||
{
|
||||
uint32_t fre_start_addr;
|
||||
const char *fre_offsets;
|
||||
unsigned char fre_info;
|
||||
} sframe_frame_row_entry;
|
||||
|
||||
/* The SFrame Decoder. */
|
||||
|
||||
/* Decode the specified SFrame buffer CF_BUF and return the new SFrame
|
||||
decoder context. */
|
||||
|
||||
extern _Unwind_Reason_Code
|
||||
__sframe_decode (sframe_decoder_ctx *dctx, const char *cf_buf);
|
||||
|
||||
/* Find the SFrame Frame Row Entry which contains the PC. Returns
|
||||
_URC_END_OF_STACK if failure. */
|
||||
|
||||
extern _Unwind_Reason_Code
|
||||
__sframe_find_fre (sframe_decoder_ctx *ctx, int32_t pc,
|
||||
sframe_frame_row_entry *frep);
|
||||
|
||||
/* Get the base reg id from the FRE info. */
|
||||
|
||||
extern uint8_t
|
||||
__sframe_fre_get_base_reg_id (sframe_frame_row_entry *fre);
|
||||
|
||||
/* Get the CFA offset from the FRE. Sets ERRP if an error is
|
||||
detected. */
|
||||
|
||||
extern int32_t
|
||||
__sframe_fre_get_cfa_offset (sframe_decoder_ctx *dtcx,
|
||||
sframe_frame_row_entry *fre,
|
||||
_Unwind_Reason_Code *errp);
|
||||
|
||||
/* Get the FP offset from the FRE. If the offset is unavailable, sets
|
||||
ERRP. */
|
||||
|
||||
extern int32_t
|
||||
__sframe_fre_get_fp_offset (sframe_decoder_ctx *dctx,
|
||||
sframe_frame_row_entry *fre,
|
||||
_Unwind_Reason_Code *errp);
|
||||
|
||||
/* Get the RA offset from the FRE. Sets ERRP if ra offset is
|
||||
unavailable. */
|
||||
|
||||
extern int32_t
|
||||
__sframe_fre_get_ra_offset (sframe_decoder_ctx *dctx,
|
||||
sframe_frame_row_entry *fre,
|
||||
_Unwind_Reason_Code *errp);
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif /* _SFRAME_API_H */
|
||||
|
|
@ -0,0 +1,187 @@
|
|||
/* Copyright (C) 2025 Free Software Foundation, Inc.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
The GNU C Library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the GNU Lesser General Public License as
|
||||
published by the Free Software Foundation; either version 2.1 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
The GNU C Library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||||
|
||||
#include <sframe-read.h>
|
||||
#include <stdlib.h>
|
||||
#include <dlfcn.h>
|
||||
#include <unwind.h>
|
||||
#include <uw-sigframe.h>
|
||||
#include <ldsodefs.h>
|
||||
|
||||
/* Some arches like s390x needs an offset to correct the value where
|
||||
SP is located in relation to CFA. */
|
||||
#ifndef SFRAME_SP_VAL_OFFSET
|
||||
#define SFRAME_SP_VAL_OFFSET 0
|
||||
#endif
|
||||
|
||||
static inline _Unwind_Ptr
|
||||
read_stack_value (_Unwind_Ptr loc)
|
||||
{
|
||||
_Unwind_Ptr value = *((_Unwind_Ptr *) loc);
|
||||
return value;
|
||||
}
|
||||
|
||||
/* Helper to avoid PLT call in libc. Fixes elf/check-localplt
|
||||
errors. */
|
||||
|
||||
static int
|
||||
_dl_find_object_helper (void *address, struct dl_find_object *result)
|
||||
{
|
||||
return GLRO (dl_find_object) (address, result);
|
||||
}
|
||||
|
||||
/* Backtrace the stack and collect the stacktrace given SFrame info.
|
||||
If successful, store the return addresses in RA_LST. The SIZE
|
||||
argument specifies the maximum number of return addresses that can
|
||||
be stored in RA_LST and contains the number of the addresses
|
||||
collected. */
|
||||
|
||||
int
|
||||
__stacktrace_sframe (void **ra_lst, int count, frame *frame)
|
||||
{
|
||||
_Unwind_Ptr sframe_vma, cfa, return_addr, ra_stack_loc, fp_stack_loc, pc,
|
||||
frame_ptr;
|
||||
int cfa_offset, fp_offset, ra_offset, i;
|
||||
sframe_frame_row_entry fred, *frep = &fred;
|
||||
|
||||
if (!ra_lst || !count)
|
||||
return 0;
|
||||
|
||||
for (i = 0; i < count; i++)
|
||||
{
|
||||
_Unwind_Reason_Code err;
|
||||
struct dl_find_object data;
|
||||
sframe_decoder_ctx decoder_context, *dctx = &decoder_context;
|
||||
|
||||
/* Clean decoder context. */
|
||||
memset (dctx, 0, sizeof (sframe_decoder_ctx));
|
||||
|
||||
/* Load and set up the SFrame stack trace info for pc. */
|
||||
if (_dl_find_object_helper ((void *) frame->pc, &data) < 0)
|
||||
/* Force fallback to DWARF stacktracer. */
|
||||
return 0;
|
||||
|
||||
sframe_vma = (_Unwind_Ptr) data.dlfo_sframe;
|
||||
if (!sframe_vma || !(data.dlfo_flags & DLFO_FLAG_SFRAME))
|
||||
{
|
||||
#ifdef MD_DECODE_SIGNAL_FRAME
|
||||
/* If there is no valid SFrame section or SFrame section is
|
||||
corrupted then check if it is a signal frame. */
|
||||
if (MD_DECODE_SIGNAL_FRAME (frame) == _URC_NO_REASON)
|
||||
{
|
||||
ra_lst[i] = (void *) frame->pc;
|
||||
continue;
|
||||
}
|
||||
#endif
|
||||
/* Force fallback to DWARF stacktracer. */
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Decode the specified SFrame buffer populate sframe's decoder
|
||||
context. */
|
||||
if (__sframe_decode (dctx, (char *) data.dlfo_sframe) != _URC_NO_REASON)
|
||||
/* Force fallback to DWARF stacktracer. */
|
||||
return 0;
|
||||
|
||||
pc = frame->pc - sframe_vma;
|
||||
/* Find the SFrame Row Entry which contains the PC. */
|
||||
if (__sframe_find_fre (dctx, pc, frep) == _URC_END_OF_STACK)
|
||||
{
|
||||
#ifdef MD_DECODE_SIGNAL_FRAME
|
||||
/* If there are no valid FREs, check if it is a signal
|
||||
frame, and if so decode it. */
|
||||
if (MD_DECODE_SIGNAL_FRAME (frame) == _URC_NO_REASON)
|
||||
{
|
||||
ra_lst[i] = (void *) frame->pc;
|
||||
continue;
|
||||
}
|
||||
#endif
|
||||
#ifdef MD_DETECT_OUTERMOST_FRAME
|
||||
if (MD_DETECT_OUTERMOST_FRAME (frame) == _URC_END_OF_STACK)
|
||||
return i;
|
||||
#endif
|
||||
/* Force fallback to DWARF stacktracer. */
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Get the CFA offset from the FRE. If offset is unavailable,
|
||||
sets err. */
|
||||
cfa_offset = __sframe_fre_get_cfa_offset (dctx, frep, &err);
|
||||
if (err != _URC_NO_REASON)
|
||||
/* Force fallback to DWARF stacktracer. */
|
||||
return 0;
|
||||
|
||||
/* Get CFA using base reg id from the FRE info. */
|
||||
cfa = ((__sframe_fre_get_base_reg_id (frep)
|
||||
== SFRAME_BASE_REG_SP) ? frame->sp : frame->fp) + cfa_offset;
|
||||
|
||||
/* Get the RA offset from the FRE. If the offset is
|
||||
unavailable, sets err. */
|
||||
ra_offset = __sframe_fre_get_ra_offset (dctx, frep, &err);
|
||||
if (err != _URC_NO_REASON)
|
||||
/* Force fallback to DWARF stacktracer. */
|
||||
return 0;
|
||||
|
||||
/* RA offset is available, get the value stored in the stack
|
||||
location. */
|
||||
ra_stack_loc = cfa + ra_offset;
|
||||
return_addr = read_stack_value (ra_stack_loc);
|
||||
|
||||
ra_lst[i] = (void *) return_addr;
|
||||
|
||||
/* Get the FP offset from the FRE. If the offset is
|
||||
unavailable, sets err. */
|
||||
fp_offset = __sframe_fre_get_fp_offset (dctx, frep, &err);
|
||||
frame_ptr = frame->fp;
|
||||
if (err == _URC_NO_REASON)
|
||||
{
|
||||
/* FP offset is available, get the value stored in the stack
|
||||
location. */
|
||||
fp_stack_loc = cfa + fp_offset;
|
||||
frame_ptr = read_stack_value (fp_stack_loc);
|
||||
}
|
||||
|
||||
/* Set up for the next frame. */
|
||||
frame->fp = frame_ptr;
|
||||
frame->sp = cfa + SFRAME_SP_VAL_OFFSET;
|
||||
frame->pc = return_addr;
|
||||
}
|
||||
return i;
|
||||
}
|
||||
|
||||
libc_hidden_def (__stacktrace_sframe);
|
||||
|
||||
/* A noinline helper used to obtain the caller's current PC. */
|
||||
|
||||
_Unwind_Ptr __attribute__ ((noinline))
|
||||
__getPC (void)
|
||||
{
|
||||
return (_Unwind_Ptr)
|
||||
__builtin_extract_return_addr (__builtin_return_address (0));
|
||||
}
|
||||
|
||||
libc_hidden_def (__getPC);
|
||||
|
||||
/* A noinline helper used to obtain the caller's current SP. It
|
||||
mimics gcc14's __builtin_stack_address() functionality. */
|
||||
|
||||
_Unwind_Ptr __attribute__ ((noinline))
|
||||
__getSP (void)
|
||||
{
|
||||
return (_Unwind_Ptr) __builtin_dwarf_cfa() + SFRAME_SP_VAL_OFFSET;
|
||||
}
|
||||
|
||||
libc_hidden_def (__getSP);
|
||||
|
|
@ -0,0 +1,367 @@
|
|||
/* SFrame format description.
|
||||
Copyright (C) 2022-2025 Free Software Foundation, Inc.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
The GNU C Library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the GNU Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 of the License, or (at your option) any later version.
|
||||
|
||||
The GNU C Library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program; see the file COPYING. If not see
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
#ifndef _SFRAME_H
|
||||
#define _SFRAME_H
|
||||
|
||||
#include <sys/types.h>
|
||||
#include <limits.h>
|
||||
#include <stdint.h>
|
||||
#include <unwind.h>
|
||||
|
||||
#ifdef __cplusplus
|
||||
extern "C"
|
||||
{
|
||||
#endif
|
||||
|
||||
/* SFrame format.
|
||||
|
||||
SFrame format is a simple format to represent the information needed
|
||||
for generating vanilla backtraces. SFrame format keeps track of the
|
||||
minimal necessary information needed for stack tracing:
|
||||
- Canonical Frame Address (CFA)
|
||||
- Frame Pointer (FP)
|
||||
- Return Address (RA)
|
||||
|
||||
The SFrame section itself has the following structure:
|
||||
|
||||
+--------+------------+---------+
|
||||
| file | function | frame |
|
||||
| header | descriptor | row |
|
||||
| | entries | entries |
|
||||
+--------+------------+---------+
|
||||
|
||||
The file header stores a magic number and version information, flags, and
|
||||
the byte offset of each of the sections relative to the end of the header
|
||||
itself. The file header also specifies the total number of Function
|
||||
Descriptor Entries, Frame Row Entries and length of the FRE sub-section.
|
||||
|
||||
Following the header is a list of Function Descriptor Entries (FDEs).
|
||||
This list may be sorted if the flags in the file header indicate it to be
|
||||
so. The sort order, if applicable, is the order of functions in the
|
||||
.text.* sections in the resulting binary artifact. Each Function
|
||||
Descriptor Entry specifies the start PC of a function, the size in bytes
|
||||
of the function and an offset to its first Frame Row Entry (FRE). Each FDE
|
||||
additionally also specifies the type of FRE it uses to encode the stack
|
||||
trace information.
|
||||
|
||||
Next, the SFrame Frame Row Entry sub-section is a list of variable size
|
||||
records. Each entry represents stack trace information for a set of PCs
|
||||
of the function. A singular Frame Row Entry is a self-sufficient record
|
||||
which contains information on how to generate stack trace from the
|
||||
applicable set of PCs.
|
||||
|
||||
*/
|
||||
|
||||
|
||||
/* SFrame format versions. */
|
||||
#define SFRAME_VERSION_1 1
|
||||
#define SFRAME_VERSION_2 2
|
||||
/* SFrame magic number. */
|
||||
#define SFRAME_MAGIC 0xdee2
|
||||
/* Current version of SFrame format. */
|
||||
#define SFRAME_VERSION SFRAME_VERSION_2
|
||||
|
||||
/* Various flags for SFrame. */
|
||||
|
||||
/* Function Descriptor Entries are sorted on PC. */
|
||||
#define SFRAME_F_FDE_SORTED 0x1
|
||||
/* Functions preserve frame pointer. */
|
||||
#define SFRAME_F_FRAME_POINTER 0x2
|
||||
|
||||
#define SFRAME_CFA_FIXED_FP_INVALID 0
|
||||
#define SFRAME_CFA_FIXED_RA_INVALID 0
|
||||
|
||||
/* Supported ABIs/Arch. */
|
||||
#define SFRAME_ABI_AARCH64_ENDIAN_BIG 1 /* AARCH64 big endian. */
|
||||
#define SFRAME_ABI_AARCH64_ENDIAN_LITTLE 2 /* AARCH64 little endian. */
|
||||
#define SFRAME_ABI_AMD64_ENDIAN_LITTLE 3 /* AMD64 little endian. */
|
||||
|
||||
/* SFrame FRE types. */
|
||||
#define SFRAME_FRE_TYPE_ADDR1 0
|
||||
#define SFRAME_FRE_TYPE_ADDR2 1
|
||||
#define SFRAME_FRE_TYPE_ADDR4 2
|
||||
|
||||
/* SFrame Function Descriptor Entry types.
|
||||
|
||||
The SFrame format has two possible representations for functions. The
|
||||
choice of which type to use is made according to the instruction patterns
|
||||
in the relevant program stub.
|
||||
|
||||
An SFrame FDE of type SFRAME_FDE_TYPE_PCINC is an indication
|
||||
that the PCs in the FREs should be treated as increments in bytes. This is
|
||||
used for a bulk of the executable code of a program, which contains
|
||||
instructions with no specific pattern.
|
||||
|
||||
An SFrame FDE of type SFRAME_FDE_TYPE_PCMASK is an indication
|
||||
that the PCs in the FREs should be treated as masks. This type is useful
|
||||
for the cases when a small pattern of instructions in a program stub is
|
||||
repeatedly to cover a specific functionality. Typical usescases are pltN
|
||||
entries, trampolines etc. */
|
||||
|
||||
/* Unwinders perform a (PC >= FRE_START_ADDR) to look up a matching FRE. */
|
||||
#define SFRAME_FDE_TYPE_PCINC 0
|
||||
/* Unwinders perform a (PC % REP_BLOCK_SIZE >= FRE_START_ADDR) to look up a
|
||||
matching FRE. */
|
||||
#define SFRAME_FDE_TYPE_PCMASK 1
|
||||
|
||||
typedef struct sframe_preamble
|
||||
{
|
||||
uint16_t sfp_magic; /* Magic number (SFRAME_MAGIC). */
|
||||
uint8_t sfp_version; /* Data format version number (SFRAME_VERSION). */
|
||||
uint8_t sfp_flags; /* Flags. */
|
||||
} __attribute__ ((packed)) sframe_preamble;
|
||||
|
||||
typedef struct sframe_header
|
||||
{
|
||||
sframe_preamble sfh_preamble;
|
||||
/* Information about the arch (endianness) and ABI. */
|
||||
uint8_t sfh_abi_arch;
|
||||
/* Offset for the Frame Pointer (FP) from CFA may be fixed for some
|
||||
ABIs (e.g, in AMD64 when -fno-omit-frame-pointer is used). When fixed,
|
||||
this field specifies the fixed stack frame offset and the individual
|
||||
FREs do not need to track it. When not fixed, it is set to
|
||||
SFRAME_CFA_FIXED_FP_INVALID, and the individual FREs may provide
|
||||
the applicable stack frame offset, if any. */
|
||||
int8_t sfh_cfa_fixed_fp_offset;
|
||||
/* Offset for the Return Address from CFA is fixed for some ABIs
|
||||
(e.g., AMD64 has it as CFA-8). When fixed, the header specifies the
|
||||
fixed stack frame offset and the individual FREs do not track it. When
|
||||
not fixed, it is set to SFRAME_CFA_FIXED_RA_INVALID, and individual
|
||||
FREs provide the applicable stack frame offset, if any. */
|
||||
int8_t sfh_cfa_fixed_ra_offset;
|
||||
/* Number of bytes making up the auxiliary header, if any.
|
||||
Some ABI/arch, in the future, may use this space for extending the
|
||||
information in SFrame header. Auxiliary header is contained in
|
||||
bytes sequentially following the sframe_header. */
|
||||
uint8_t sfh_auxhdr_len;
|
||||
/* Number of SFrame FDEs in this SFrame section. */
|
||||
uint32_t sfh_num_fdes;
|
||||
/* Number of SFrame Frame Row Entries. */
|
||||
uint32_t sfh_num_fres;
|
||||
/* Number of bytes in the SFrame Frame Row Entry section. */
|
||||
uint32_t sfh_fre_len;
|
||||
/* Offset of SFrame Function Descriptor Entry section. */
|
||||
uint32_t sfh_fdeoff;
|
||||
/* Offset of SFrame Frame Row Entry section. */
|
||||
uint32_t sfh_freoff;
|
||||
} __attribute__ ((packed)) sframe_header;
|
||||
|
||||
#define SFRAME_V1_HDR_SIZE(sframe_hdr) \
|
||||
((sizeof (sframe_header) + (sframe_hdr).sfh_auxhdr_len))
|
||||
|
||||
/* Two possible keys for executable (instruction) pointers signing. */
|
||||
#define SFRAME_AARCH64_PAUTH_KEY_A 0 /* Key A. */
|
||||
#define SFRAME_AARCH64_PAUTH_KEY_B 1 /* Key B. */
|
||||
|
||||
typedef struct sframe_func_desc_entry
|
||||
{
|
||||
/* Function start address. Encoded as a signed offset, relative to the
|
||||
beginning of the current FDE. */
|
||||
int32_t sfde_func_start_address;
|
||||
/* Size of the function in bytes. */
|
||||
uint32_t sfde_func_size;
|
||||
/* Offset of the first SFrame Frame Row Entry of the function, relative to the
|
||||
beginning of the SFrame Frame Row Entry sub-section. */
|
||||
uint32_t sfde_func_start_fre_off;
|
||||
/* Number of frame row entries for the function. */
|
||||
uint32_t sfde_func_num_fres;
|
||||
/* Additional information for stack tracing from the function:
|
||||
- 4-bits: Identify the FRE type used for the function.
|
||||
- 1-bit: Identify the FDE type of the function - mask or inc.
|
||||
- 1-bit: PAC authorization A/B key (aarch64).
|
||||
- 2-bits: Unused.
|
||||
------------------------------------------------------------------------
|
||||
| Unused | PAC auth A/B key (aarch64) | FDE type | FRE type |
|
||||
| | Unused (amd64) | | |
|
||||
------------------------------------------------------------------------
|
||||
8 6 5 4 0 */
|
||||
uint8_t sfde_func_info;
|
||||
/* Size of the block of repeating insns. Used for SFrame FDEs of type
|
||||
SFRAME_FDE_TYPE_PCMASK. */
|
||||
uint8_t sfde_func_rep_size;
|
||||
uint16_t sfde_func_padding2;
|
||||
} __attribute__ ((packed)) sframe_func_desc_entry;
|
||||
|
||||
/* Macros to compose and decompose function info in FDE. */
|
||||
|
||||
/* Note: Set PAC auth key to SFRAME_AARCH64_PAUTH_KEY_A by default. */
|
||||
#define SFRAME_V1_FUNC_INFO(fde_type, fre_enc_type) \
|
||||
(((SFRAME_AARCH64_PAUTH_KEY_A & 0x1) << 5) | \
|
||||
(((fde_type) & 0x1) << 4) | ((fre_enc_type) & 0xf))
|
||||
|
||||
#define SFRAME_V1_FUNC_FRE_TYPE(data) ((data) & 0xf)
|
||||
#define SFRAME_V1_FUNC_FDE_TYPE(data) (((data) >> 4) & 0x1)
|
||||
#define SFRAME_V1_FUNC_PAUTH_KEY(data) (((data) >> 5) & 0x1)
|
||||
|
||||
/* Set the pauth key as indicated. */
|
||||
#define SFRAME_V1_FUNC_INFO_UPDATE_PAUTH_KEY(pauth_key, fde_info) \
|
||||
((((pauth_key) & 0x1) << 5) | ((fde_info) & 0xdf))
|
||||
|
||||
/* Size of stack frame offsets in an SFrame Frame Row Entry. A single
|
||||
SFrame FRE has all offsets of the same size. Offset size may vary
|
||||
across frame row entries. */
|
||||
#define SFRAME_FRE_OFFSET_1B 0
|
||||
#define SFRAME_FRE_OFFSET_2B 1
|
||||
#define SFRAME_FRE_OFFSET_4B 2
|
||||
|
||||
/* An SFrame Frame Row Entry can be SP or FP based. */
|
||||
#define SFRAME_BASE_REG_FP 0
|
||||
#define SFRAME_BASE_REG_SP 1
|
||||
|
||||
/* The index at which a specific offset is presented in the variable length
|
||||
bytes of an FRE. */
|
||||
#define SFRAME_FRE_CFA_OFFSET_IDX 0
|
||||
/* The RA stack offset, if present, will always be at index 1 in the variable
|
||||
length bytes of the FRE. */
|
||||
#define SFRAME_FRE_RA_OFFSET_IDX 1
|
||||
/* The FP stack offset may appear at offset 1 or 2, depending on the ABI as RA
|
||||
may or may not be tracked. */
|
||||
#define SFRAME_FRE_FP_OFFSET_IDX 2
|
||||
|
||||
typedef struct sframe_fre_info
|
||||
{
|
||||
/* Information about
|
||||
- 1 bit: base reg for CFA
|
||||
- 4 bits: Number of offsets (N). A value of upto 3 is allowed to track
|
||||
all three of CFA, FP and RA (fixed implicit order).
|
||||
- 2 bits: information about size of the offsets (S) in bytes.
|
||||
Valid values are SFRAME_FRE_OFFSET_1B, SFRAME_FRE_OFFSET_2B,
|
||||
SFRAME_FRE_OFFSET_4B
|
||||
- 1 bit: Mangled RA state bit (aarch64 only).
|
||||
----------------------------------------------------------------------------------
|
||||
| Mangled-RA (aarch64) | Size of offsets | Number of offsets | base_reg |
|
||||
| Unused (amd64) | | | |
|
||||
----------------------------------------------------------------------------------
|
||||
8 7 5 1 0
|
||||
|
||||
*/
|
||||
uint8_t fre_info;
|
||||
} sframe_fre_info;
|
||||
|
||||
/* Macros to compose and decompose FRE info. */
|
||||
|
||||
/* Note: Set mangled_ra_p to zero by default. */
|
||||
#define SFRAME_V1_FRE_INFO(base_reg_id, offset_num, offset_size) \
|
||||
(((0 & 0x1) << 7) | (((offset_size) & 0x3) << 5) | \
|
||||
(((offset_num) & 0xf) << 1) | ((base_reg_id) & 0x1))
|
||||
|
||||
/* Set the mangled_ra_p bit as indicated. */
|
||||
#define SFRAME_V1_FRE_INFO_UPDATE_MANGLED_RA_P(mangled_ra_p, fre_info) \
|
||||
((((mangled_ra_p) & 0x1) << 7) | ((fre_info) & 0x7f))
|
||||
|
||||
#define SFRAME_V1_FRE_CFA_BASE_REG_ID(data) ((data) & 0x1)
|
||||
#define SFRAME_V1_FRE_OFFSET_COUNT(data) (((data) >> 1) & 0xf)
|
||||
#define SFRAME_V1_FRE_OFFSET_SIZE(data) (((data) >> 5) & 0x3)
|
||||
#define SFRAME_V1_FRE_MANGLED_RA_P(data) (((data) >> 7) & 0x1)
|
||||
|
||||
/* SFrame Frame Row Entry definitions.
|
||||
|
||||
Used for both AMD64 and AARCH64.
|
||||
|
||||
An SFrame Frame Row Entry is a self-sufficient record which contains
|
||||
information on how to generate the stack trace for the specified range of
|
||||
PCs. Each SFrame Frame Row Entry is followed by S*N bytes, where:
|
||||
S is the size of the stack frame offset for the FRE, and
|
||||
N is the number of stack frame offsets in the FRE
|
||||
|
||||
The interpretation of FRE stack offsets is ABI-specific:
|
||||
|
||||
AMD64:
|
||||
offset1 (interpreted as CFA = BASE_REG + offset1)
|
||||
if FP is being tracked
|
||||
offset2 (intrepreted as FP = CFA + offset2)
|
||||
fi
|
||||
|
||||
AARCH64:
|
||||
offset1 (interpreted as CFA = BASE_REG + offset1)
|
||||
if FP is being tracked (in other words, if frame record created)
|
||||
offset2 (interpreted as RA = CFA + offset2)
|
||||
offset3 (intrepreted as FP = CFA + offset3)
|
||||
fi
|
||||
Note that in AAPCS64, a frame record, if created, will save both FP and
|
||||
LR on stack.
|
||||
*/
|
||||
|
||||
/* Used when SFRAME_FRE_TYPE_ADDR1 is specified as FRE type. */
|
||||
typedef struct sframe_frame_row_entry_addr1
|
||||
{
|
||||
/* Start address of the frame row entry. Encoded as an 1-byte unsigned
|
||||
offset, relative to the start address of the function. */
|
||||
uint8_t sfre_start_address;
|
||||
sframe_fre_info sfre_info;
|
||||
} __attribute__ ((packed)) sframe_frame_row_entry_addr1;
|
||||
|
||||
/* Upper limit of start address in sframe_frame_row_entry_addr1
|
||||
is 0x100 (not inclusive). */
|
||||
#define SFRAME_FRE_TYPE_ADDR1_LIMIT \
|
||||
(1ULL << ((SFRAME_FRE_TYPE_ADDR1 + 1) * 8))
|
||||
|
||||
/* Used when SFRAME_FRE_TYPE_ADDR2 is specified as FRE type. */
|
||||
typedef struct sframe_frame_row_entry_addr2
|
||||
{
|
||||
/* Start address of the frame row entry. Encoded as an 2-byte unsigned
|
||||
offset, relative to the start address of the function. */
|
||||
uint16_t sfre_start_address;
|
||||
sframe_fre_info sfre_info;
|
||||
} __attribute__ ((packed)) sframe_frame_row_entry_addr2;
|
||||
|
||||
/* Upper limit of start address in sframe_frame_row_entry_addr2
|
||||
is 0x10000 (not inclusive). */
|
||||
#define SFRAME_FRE_TYPE_ADDR2_LIMIT \
|
||||
(1ULL << ((SFRAME_FRE_TYPE_ADDR2 * 2) * 8))
|
||||
|
||||
/* Used when SFRAME_FRE_TYPE_ADDR4 is specified as FRE type. */
|
||||
typedef struct sframe_frame_row_entry_addr4
|
||||
{
|
||||
/* Start address of the frame row entry. Encoded as a 4-byte unsigned
|
||||
offset, relative to the start address of the function. */
|
||||
uint32_t sfre_start_address;
|
||||
sframe_fre_info sfre_info;
|
||||
} __attribute__ ((packed)) sframe_frame_row_entry_addr4;
|
||||
|
||||
/* Upper limit of start address in sframe_frame_row_entry_addr2
|
||||
is 0x100000000 (not inclusive). */
|
||||
#define SFRAME_FRE_TYPE_ADDR4_LIMIT \
|
||||
(1ULL << ((SFRAME_FRE_TYPE_ADDR4 * 2) * 8))
|
||||
|
||||
/* Used to pass frame information to stack trace routine. */
|
||||
typedef struct cframe
|
||||
{
|
||||
_Unwind_Ptr pc;
|
||||
_Unwind_Ptr sp;
|
||||
_Unwind_Ptr fp;
|
||||
} frame;
|
||||
|
||||
/* SFrame stack tracing support. */
|
||||
int __stacktrace_sframe (void **, int, frame *);
|
||||
libc_hidden_proto (__stacktrace_sframe);
|
||||
|
||||
/* Helper used by SFrame tracing algorithm. */
|
||||
_Unwind_Ptr __getPC (void);
|
||||
libc_hidden_proto (__getPC);
|
||||
|
||||
/* Helper used by SFrame tracing algorithm. */
|
||||
_Unwind_Ptr __getSP (void);
|
||||
libc_hidden_proto (__getSP);
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif /* _SFRAME_H */
|
||||
|
|
@ -0,0 +1,31 @@
|
|||
/* Internal header file for handling signal frames. Generic version.
|
||||
Copyright (C) 2025 Free Software Foundation, Inc.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
The GNU C Library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the GNU Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 of the License, or (at your option) any later version.
|
||||
|
||||
The GNU C Library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with the GNU C Library; if not, see
|
||||
<https://www.gnu.org/licenses/>. */
|
||||
|
||||
/* Each architecture that supports SFrame may need to define several
|
||||
macros to handle exceptional cases during stack backtracing.
|
||||
|
||||
MD_DECODE_SIGNAL_FRAME(frame) should recover frame information when
|
||||
a signal-related exception occurs. The input frame must contain a
|
||||
valid program counter (PC) field. On success, the macro should
|
||||
return _URC_NO_REASON.
|
||||
|
||||
MD_DETECT_OUTERMOST_FRAME(frame) is used to detect the outermost
|
||||
stack frame. It returns _URC_NO_REASON upon successful
|
||||
detection.
|
||||
|
||||
The FRAME structure is defined in sysdeps/generic/sframe.h */
|
||||
Loading…
Reference in New Issue