Add an appendix to provide a rough outline to show how to generate stack
traces using the SFrame format. Such content should hopefully aid the
reader assimmilate the information in the specification.
libsframe/
* doc/sframe-spec.texi: Add new appendix.
The recipe to interpret the SFrame FRE stack offsets is
ABI/arch-specific.
Although, there is other information in the specification that is
ABI-specific (like pauth_key usage in AArch64), those pieces of
information are now assimmilated in the SFrame specification in a way
that it is fairly difficult to carve then out into a ABI/arch-specific
section without confusing the readers.
For future though, the specification must strive to keep the generic
parts and ABI/arch-specific parts clearly laid out in separate sections.
libsframe/
* doc/sframe-spec.texi: Reorder and adapt the contents.
Update some of the content to make the specification document hopefully
clearer:
- Fix some typos.
- Use Title case consistently for headings.
- Update text around detection of foreign endianness.
- Split the structure field "Name" in each table to two separate
colunms for additional attention: "Type" and "Name".
- Rename "SFrame endianness" section to "SFrame magic number and
endianness"
- Update text around provisions for extending SFrame for future
ABIs/architectures. Make it clear by tagging all provisions with an
explicit index item "Provisions for future ABIs".
- Add a paragraph on sort order of SFrame FDEs.
- Add a statement for SFRAME_F_FRAME_POINTER flag.
- Add a statement to assert that SFrame version 1 is now obsolete and
should not be used.
libsframe/
* doc/sframe-spec.texi: Small improvements for readability.
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.
Add details for the changes made from Version 1 to Version 2 of the format.
Also add details about alignment in the SFrame format. A portion of the
SFrame stack trace format has an unaligned on-disk representation. Add
description at relevant points in the specificatin to clarify the
alignment related details.
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.
'make pdf' in libsframe shows some warnings, some of which (especially
the Overfull warnings) are causing undesirable effects on the rendered
output. Few examples of the warnings:
Underfull \hbox (badness 10000) in paragraph at lines 406--407
@texttt pauth_
Underfull \hbox (badness 10000) in paragraph at lines 407--410
@textrm Specify which key is used for signing the return
...
Overfull \hbox (2.0987pt too wide) in paragraph at lines 412--413
@texttt fdetype[]|
...
Overfull \hbox (28.87212pt too wide) in paragraph at lines 446--447
@textrm SFRAME[]FDE[]TYPE[]PCMASK|
...
This patch adjusts column widths of the affected cells to fix a subset
of these warnings. For the rest of the warnings, use explicit newline
command to fix them.
libsframe/
* doc/sframe-spec.texi: Fix various underfull and overfull
warnings.
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.
xrefautomaticsectiontitle appears to be available from texinfo 5.0 or
greater. As such, it is not worthwhile to add requirement for a minimum
necessary makeinfo version. So remove the usage of it.
Also align node name with section title where possible.
ChangeLog:
* libsframe/doc/sframe-spec.texi: Remove usage of
xrefautomaticsectiontitle.
ChangeLog:
* libsframe/Makefile.am: Add info-in-builddir to
AUTOMAKE_OPTIONS. Include doc/local.mk.
* libsframe/Makefile.in: Regenerated.
* libsframe/configure: Likewise.
* libsframe/configure.ac: Check for makeinfo and set BUILD_INFO.
* libsframe/doc/local.mk: New file.
* libsframe/doc/sframe-spec.texi: Likewise.
