Document a limitation of the DW_CFA_AARCH64_negate_ra_state.#129
Merged
stuij merged 1 commit intoARM-software:mainfrom Mar 14, 2022
Merged
Conversation
nsz-arm
reviewed
Feb 10, 2022
aadwarf64/aadwarf64.rst
Outdated
|
|
||
| The ``DW_CFA_AARCH64_negate_ra_state`` operation negates bit[0] of the | ||
| RA_SIGN_STATE pseudo-register. It does not take any operands. | ||
| The ``DW_CFA_AARCH64_negate_ra_state`` shall not be mixed with other DWARF operations on the |
Contributor
There was a problem hiding this comment.
i think we should use the "Register Rule Instruction" terminology from 6.4.2.3 of https://www.dwarfstd.org/doc/DWARF5.pdf
because we want to allow "Row State Instructions" from 6.4.2.4. to be mixed with negate_ra_state.
Contributor
There was a problem hiding this comment.
either that or we should call out DW_CFA_remember_state/restore_state explicitly.
DanielKristofKiss
force-pushed
the
DW_CFA_AARRCH64_negate_ra_state
branch
from
8f68214 to
424fff7
Compare
walkerkd
reviewed
Feb 24, 2022
Contributor
walkerkd
left a comment
walkerkd
left a comment
There was a problem hiding this comment.
In general this looks OK to me.
Minor wording nit-pick. The DWARF standard does not use "shall not", instead it uses "must not". Suggest we do the same here.
DW_CFA_AARCH64_negate_ra_state depends on the previous state of the RA_SIGN_STATE register which makes complex to handle in cases when the register is set by DWARF expressions because expression are lasily evaulated in runtime.
DanielKristofKiss
force-pushed
the
DW_CFA_AARRCH64_negate_ra_state
branch
from
424fff7 to
81a633f
Compare
Contributor
Author
|
@walkerkd Thanks, done. |
walkerkd
approved these changes
Mar 7, 2022
|
Looks good to me |
DanielKristofKiss
added a commit
to llvm/llvm-project
that referenced
this pull request
May 13, 2022
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692
DanielKristofKiss
added a commit
to llvm/llvm-project
that referenced
this pull request
May 18, 2022
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 Reland: test moved because it depends on exceptions.
mem-frob
pushed a commit
to draperlaboratory/hope-llvm-project
that referenced
this pull request
Oct 7, 2022
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692
mem-frob
pushed a commit
to draperlaboratory/hope-llvm-project
that referenced
this pull request
Oct 7, 2022
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 Reland: test moved because it depends on exceptions.
arichardson
pushed a commit
to CTSRD-CHERI/libunwind
that referenced
this pull request
Sep 12, 2023
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692
arichardson
pushed a commit
to CTSRD-CHERI/libunwind
that referenced
this pull request
Sep 12, 2023
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 Reland: test moved because it depends on exceptions.
liujinye-sys
pushed a commit
to open-vela/nuttx_libs_libxx_libcxxabi
that referenced
this pull request
Nov 25, 2024
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 Reland: test moved because it depends on exceptions.
oneseer
pushed a commit
to oneseer/libcxxabi
that referenced
this pull request
Mar 26, 2025
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 Reland: test moved because it depends on exceptions. NOKEYCHECK=True GitOrigin-RevId: c218fd3d7d3764eb123c8429bbcd33bacfe2e633
oneseer
pushed a commit
to oneseer/libunwind
that referenced
this pull request
Mar 26, 2025
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 NOKEYCHECK=True GitOrigin-RevId: f6366ef7f4f3cf1182fd70e0c50a9fa54374b612
oneseer
pushed a commit
to oneseer/libunwind
that referenced
this pull request
Mar 26, 2025
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 Reland: test moved because it depends on exceptions. NOKEYCHECK=True GitOrigin-RevId: c218fd3d7d3764eb123c8429bbcd33bacfe2e633
openvela-robot
pushed a commit
to open-vela/nuttx_libs_libxx_libcxxabi
that referenced
this pull request
Jul 23, 2025
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 Reland: test moved because it depends on exceptions.
liujinye-sys
pushed a commit
to open-vela/nuttx_libs_libxx_libcxxabi
that referenced
this pull request
Dec 16, 2025
Program may set the RA_SIGN_STATE pseudo register by expressions. Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value of the register which leads to runtime errors on PAC enabled systems. In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions. [1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1 [2] ARM-software/abi-aa#129 Reviewed By: #libunwind, MaskRay Differential Revision: https://reviews.llvm.org/D123692 Reland: test moved because it depends on exceptions.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
5 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
DW_CFA_AARCH64_negate_ra_state depends on the previous state of the RA_SIGN_STATE
register which makes complex to handle in cases when the register is set by
DWARF expressions because expression are lasily evaulated in runtime.