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2024-07-09include: sframe: update code comments around SFrame FRE stack offsetsIndu Bhagat1-10/+12
This also amends the incorrect comment: offset3 (intrepreted as FP = CFA + offset2) If RA tracking is enabled, the offset to recover FP is at the third index. The SFrame format (V2) has assumption that if FP is saved on stack, RA must have been saved as well. This is true for the currently supported arch Aarch64. For AMD64, RA tracking per SFrame FRE is not necessary. In future, when extending support for more architectures, this will likely need to be revisited. include/ * sframe.h: Make the comments clearer by enumerating what happens per-ABI.
2024-01-04Update year range in copyright notice of binutils filesAlan Modra1-1/+1
Adds two new external authors to etc/update-copyright.py to cover bfd/ax_tls.m4, and adds gprofng to dirs handled automatically, then updates copyright messages as follows: 1) Update cgen/utils.scm emitted copyrights. 2) Run "etc/update-copyright.py --this-year" with an extra external author I haven't committed, 'Kalray SA.', to cover gas testsuite files (which should have their copyright message removed). 3) Build with --enable-maintainer-mode --enable-cgen-maint=yes. 4) Check out */po/*.pot which we don't update frequently.
2023-06-29sframe: bfd: gas: ld: format bump to SFrame version 2Indu Bhagat1-1/+6
SFrame version 2 encodes the size of repetitive insn block explicitly in the format. Add information in the SFrame FDE to convey the size of the block of repeating instructions. This information is used only for SFrame FDEs of type SFRAME_FDE_TYPE_PCMASK. Introduce two extra bytes for padding: this ensures that the memory accesses to the members of the SFrame Frame Descriptor Entry (FDE) are naturally aligned. gas generates SFrame section with version SFRAME_VERSION_2 by default. libsframe provides two new APIs to: - get an SFrame FDE data from the decoder context, and - add an SFrame FDE to the encoder context. The additional argument (for rep_block_size) is useful for SFrame FDEs where FDE type is SFRAME_FDE_TYPE_PCMASK. The linker will generate the output SFrame sections in the SFRAME_VERSION_2 format. If the input sections offered to the linker are not all in the SFRAME_VERSION_2 format, the linker issues an error to the user. objdump/readelf will show the following message to the user if .sframe section in SFRAME_VERSION_1 format is seen: "No further information can be displayed. SFrame version not supported." In other words, like the rest of the binutils, only the current SFrame format version, i.e., SFRAME_VERSION_2 is supported by the textual dump facilities. bfd/ * elf-sframe.c (_bfd_elf_merge_section_sframe): Generate an output SFrame section with version SFRAME_VERSION_2. Also, error out if the SFrame sections do not all have SFRAME_VERSION_2. * elfxx-x86.c (_bfd_x86_elf_create_sframe_plt): Generate SFrame section for plt entries with version SFRAME_VERSION_2. gas/ * gen-sframe.c (sframe_set_version): Update to SFRAME_VERSION_2. (output_sframe): Likewise. gas/testsuite/ * gas/cfi-sframe/cfi-sframe-aarch64-1.d: Use SFRAME_VERSION_2. * gas/cfi-sframe/cfi-sframe-aarch64-2.d: Likewise. * gas/cfi-sframe/cfi-sframe-aarch64-pac-ab-key-1.d: Likewise. * gas/cfi-sframe/cfi-sframe-common-1.d: Likewise. * gas/cfi-sframe/cfi-sframe-common-2.d: Likewise. * gas/cfi-sframe/cfi-sframe-common-3.d: Likewise. * gas/cfi-sframe/cfi-sframe-common-4.d: Likewise. * gas/cfi-sframe/cfi-sframe-common-5.d: Likewise. * gas/cfi-sframe/cfi-sframe-common-6.d: Likewise. * gas/cfi-sframe/cfi-sframe-common-7.d: Likewise. * gas/cfi-sframe/cfi-sframe-common-8.d: Likewise. * gas/cfi-sframe/cfi-sframe-x86_64-1.d: Likewise. * gas/cfi-sframe/common-empty-1.d: Likewise. * gas/cfi-sframe/common-empty-2.d: Likewise. * gas/cfi-sframe/common-empty-3.d: Likewise. ld/testsuite/ * ld-aarch64/sframe-simple-1.d: Adjust for SFRAME_VERSION_2. * ld-x86-64/sframe-plt-1.d: Likewise. * ld-x86-64/sframe-simple-1.d: Likewise. libsframe/ * libsframe.ver: Add the new APIs. * sframe.c (sframe_decoder_get_funcdesc_v2): New definition. (sframe_encoder_add_funcdesc_v2): Likewise. (sframe_header_sanity_check_p): Include SFRAME_VERSION_2. (sframe_fre_check_range_p): Get rep_block_size info from SFrame FDE. * sframe-dump.c (dump_sframe_header): Add support for SFRAME_VERSION_2. (dump_sframe): Inform user if SFrame section in SFRAME_VERSION_1 format is seen. libsframe/testsuite/ * libsframe.decode/DATA-BE: Regenerated data file. * libsframe.decode/DATA1: Likewise. * libsframe.decode/DATA2: Likewise. * libsframe.find/plt-findfre-1.c: Use new API in the testcase. include/ * sframe.h: Add member to encode size of the code block of repeating instructions. Add 2 bytes of padding. * sframe-api.h (sframe_decoder_get_funcdesc_v2): New declaration. (sframe_encoder_add_funcdesc_v2): Likewise.
2023-06-29libsframe: fix sframe_find_fre for pltN entriesIndu Bhagat1-2/+2
For a toy application on x86_64, for example, following is the SFrame stack trace information for the 3 pltN entries of 16 bytes each: func idx [1]: pc = 0x401030, size = 48 bytes STARTPC[m] CFA FP RA 0000000000000000 sp+8 u u 000000000000000b sp+16 u u The data in first column is the start_ip_offset. Also note that the FDE is of type SFRAME_FDE_TYPE_PCMASK (denoted by the [m] on LHS). Where each pltN (note: excluding plt0 entry) entry looks like: 401030: jmp *0x2fca(%rip) 401036: push $0x0 40103b: jmp 401020<_init+0x20> 401040: jmp *0x2fc2(%rip) 401046: push $0x1 40104b: jmp 401020<_init+0x20> 401050: jmp *0x2fba(%rip) 401056: push $0x2 40105b: jmp 401020<_init+0x20> Now, to find SFrame stack trace information from an FDE of type SFRAME_FDE_TYPE_PCMASK, sframe_find_fre () was doing an operation like, (start_ip_offset & 0xf) >= (pc & 0xf) This works for pltN entry of size, say, less than 16 bytes. But if the pltN entries or similar code stubs (for which SFrame FDE of type SFRAME_FDE_TYPE_PCMASK may be used), evolve to be of size > 16 bytes, this will cease to work. To match the range covered by the SFrame FRE, one should instead perform a modulo operation. The constant for the modulo operation must be the size of the pltN entry. Further, this constant should ideally be encoded in the format, as it may be different for each ABI. In SFrame Version 2 of the format, we will move towards encoding it explicitly in the SFrame FDE. For now, fix up the logic to at least move towards modulo operation. libsframe/ * sframe.c (sframe_fre_check_range_p): New definition. (sframe_find_fre): Refactor a bit and use the new definition above. include/ * sframe.h (SFRAME_FDE_TYPE_PCMASK): Update comment. libsframe/doc/ * sframe-spec.texi: Fix the text for SFRAME_FDE_TYPE_PCMASK FDE type.
2023-04-19sframe: correct some typosIndu Bhagat1-2/+2
include/ * sframe.h: Correct a typo. libsframe/ * sframe.c: Likewise.
2023-02-02sframe: use "stack trace" instead of "unwind" for SFrameIndu Bhagat1-14/+14
SFrame format is meant for generating stack traces only. include/ * sframe.h: Fix comments in the header file.
2023-01-06sframe: fix the defined SFRAME_FRE_TYPE_*_LIMIT constantsIndu Bhagat1-3/+6
An earlier commit 3f107464 defined the SFRAME_FRE_TYPE_*_LIMIT constants. These constants are used (by gas and libsframe) to pick an SFrame FRE type based on the function size. Those constants, however, were buggy, causing the generated SFrame sections to be bloated as SFRAME_FRE_TYPE_ADDR2/SFRAME_FRE_TYPE_ADDR4 got chosen more often than necessary. gas/ * sframe-opt.c (sframe_estimate_size_before_relax): Use typecast. (sframe_convert_frag): Likewise. libsframe/ * sframe.c (sframe_calc_fre_type): Use a more appropriate type for argument. Adjust the check for SFRAME_FRE_TYPE_ADDR4_LIMIT to keep it warning-free but meaningful. include/ * sframe-api.h (sframe_calc_fre_type): Use a more appropriate type for the argument. * sframe.h (SFRAME_FRE_TYPE_ADDR1_LIMIT): Correct the constant. (SFRAME_FRE_TYPE_ADDR2_LIMIT): Likewise. (SFRAME_FRE_TYPE_ADDR4_LIMIT): Likewise.
2023-01-01Update year range in copyright notice of binutils filesAlan Modra1-1/+1
The newer update-copyright.py fixes file encoding too, removing cr/lf on binutils/bfdtest2.c and ld/testsuite/ld-cygwin/exe-export.exp, and embedded cr in binutils/testsuite/binutils-all/ar.exp string match.
2022-12-22sframe.h: add support for .cfi_b_key_frameIndu Bhagat1-6/+19
ARM 8.3 provides five separate keys that can be used to authenticate pointers. There are two key for executable (instruction) pointers. The enum pointer_auth_key in gas/config/tc-aarch64.h currently holds two keys: enum pointer_auth_key { AARCH64_PAUTH_KEY_A, AARCH64_PAUTH_KEY_B }; Analogous to the above, in SFrame format V1, a bit is reserved in the SFrame FDE to indicate which key is used for signing the frame's return addresses: - SFRAME_AARCH64_PAUTH_KEY_A has a value of 0 - SFRAME_AARCH64_PAUTH_KEY_B has a value of 1 Note that the information in this bit will always be used along with the mangled_ra_p bit, the latter indicates whether the return addresses are mangled/contain PAC auth bits. include/ChangeLog: * sframe.h (SFRAME_AARCH64_PAUTH_KEY_A): New definition. (SFRAME_AARCH64_PAUTH_KEY_B): Likewise. (SFRAME_V1_FUNC_INFO): Adjust to accommodate pauth_key. (SFRAME_V1_FUNC_PAUTH_KEY): New macro. (SFRAME_V1_FUNC_INFO_UPDATE_PAUTH_KEY): Likewise.
2022-12-16sframe.h: add support for .cfi_negate_ra_stateIndu Bhagat1-8/+15
Use the last remaining bit in the 'SFrame FRE info' word to store whether the RA is signed/unsigned with PAC authorization code: this bit is named as the "mangled RA" bit. This bit is still unused for x86-64. The behaviour of the mangled-RA info bit in SFrame format closely follows the behaviour of DW_CFA_AARCH64_negate_ra_state in DWARF. During unwinding, whenever an SFrame FRE with non-zero "mangled RA" bit is encountered, it means the upper bits of the return address contain Pointer Authentication code. The unwinder, hence, must use appropriate means to restore LR correctly in such cases. include/ChangeLog: * sframe.h (SFRAME_V1_FRE_INFO_UPDATE_MANGLED_RA_P): New macro. (SFRAME_V1_FRE_MANGLED_RA_P): Likewise.
2022-12-09sframe: gas: libsframe: define constants and remove magic numbersIndu Bhagat1-0/+15
Define constants in sframe.h for the various limits associated with the range of offsets that can be encoded in the start address of an SFrame FRE. E.g., sframe_frame_row_entry_addr1 is used when start address offset can be encoded as 1-byte unsigned value. Update the code in gas to use these defined constants as it checks for these limits, and remove the usage of magic numbers. ChangeLog: * gas/sframe-opt.c (sframe_estimate_size_before_relax): (sframe_convert_frag): Do not use magic numbers. * libsframe/sframe.c (sframe_calc_fre_type): Likewise. include/ChangeLog: * sframe.h (SFRAME_FRE_TYPE_ADDR1_LIMIT): New constant. (SFRAME_FRE_TYPE_ADDR2_LIMIT): Likewise. (SFRAME_FRE_TYPE_ADDR4_LIMIT): Likewise.
2022-12-09sframe.h: make some macros more preciseIndu Bhagat1-3/+4
include/ChangeLog: * sframe.h (SFRAME_V1_FUNC_INFO): Use specific bits only. (SFRAME_V1_FRE_INFO): Likewise.
2022-11-15sframe.h: Add SFrame format definitionIndu Bhagat1-0/+303
The header sframe.h defines the SFrame format. The SFrame format is the Simple Frame format. It can be used to represent the minimal necessary unwind information required for backtracing. The current version supports AMD64 and AARCH64. More details of the SFrame format are included in the documentation of the header file in this patch. include/ChangeLog: * sframe.h: New file.
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