sys-devel/gdb: fix runtime debugging on sparc

Closes: https://bugs.gentoo.org/907906
Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 439 insertions, 0 deletions

diff --git a/sys-devel/gdb/files/gdb-13.2-fix-sparc-debugging.patch b/sys-devel/gdb/files/gdb-13.2-fix-sparc-debugging.patch
new file mode 100644
index 000000000000..3d5201cd94e3
--- /dev/null
+++ b/sys-devel/gdb/files/gdb-13.2-fix-sparc-debugging.patch
@@ -0,0 +1,126 @@
+https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=31a56a22c45d76df4c597439f337e3f75ac3065c
+https://sourceware.org/bugzilla/show_bug.cgi?id=30525
+https://bugs.gentoo.org/907906
+
+From 31a56a22c45d76df4c597439f337e3f75ac3065c Mon Sep 17 00:00:00 2001
+From: Pedro Alves <pedro@palves.net>
+Date: Wed, 7 Jun 2023 10:38:14 +0100
+Subject: [PATCH] Linux: Avoid pread64/pwrite64 for high memory addresses (PR
+ gdb/30525)
+
+Since commit 05c06f318fd9 ("Linux: Access memory even if threads are
+running"), GDB prefers pread64/pwrite64 to access inferior memory
+instead of ptrace.  That change broke reading shared libraries on
+SPARC64 Linux, as reported by PR gdb/30525 ("gdb cannot read shared
+libraries on SPARC64").
+
+On SPARC64 Linux, surprisingly (to me), userspace shared libraries are
+mapped at high 64-bit addresses:
+
+   (gdb) info sharedlibrary
+   Cannot access memory at address 0xfff80001002011e0
+   Cannot access memory at address 0xfff80001002011d8
+   Cannot access memory at address 0xfff80001002011d8
+   From                To                  Syms Read   Shared Object Library
+   0xfff80001000010a0  0xfff8000100021f80  Yes (*)     /lib64/ld-linux.so.2
+   (*): Shared library is missing debugging information.
+
+Those addresses are 64-bit addresses with the high bits set.  When
+interpreted as signed, they're negative.
+
+The Linux kernel rejects pread64/pwrite64 if the offset argument of
+type off_t (a signed type) is negative, which happens if the memory
+address we're accessing has its high bit set.  See
+linux/fs/read_write.c sys_pread64 and sys_pwrite64 in Linux.
+
+Thankfully, lseek does not fail in that situation.  So the fix is to
+use the 'lseek + read|write' path if the offset would be negative.
+
+Fix this in both native GDB and GDBserver.
+
+Tested on a SPARC64 GNU/Linux and x86-64 GNU/Linux.
+
+Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30525
+Change-Id: I79c724f918037ea67b7396fadb521bc9d1b10dc5
+--- a/gdb/linux-nat.c
++++ b/gdb/linux-nat.c
+@@ -3909,18 +3909,26 @@ linux_proc_xfer_memory_partial_fd (int fd, int pid,
+ 
+   gdb_assert (fd != -1);
+ 
+-  /* Use pread64/pwrite64 if available, since they save a syscall and can
+-     handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
+-     debugging a SPARC64 application).  */
++  /* Use pread64/pwrite64 if available, since they save a syscall and
++     can handle 64-bit offsets even on 32-bit platforms (for instance,
++     SPARC debugging a SPARC64 application).  But only use them if the
++     offset isn't so high that when cast to off_t it'd be negative, as
++     seen on SPARC64.  pread64/pwrite64 outright reject such offsets.
++     lseek does not.  */
+ #ifdef HAVE_PREAD64
+-  ret = (readbuf ? pread64 (fd, readbuf, len, offset)
+-	 : pwrite64 (fd, writebuf, len, offset));
+-#else
+-  ret = lseek (fd, offset, SEEK_SET);
+-  if (ret != -1)
+-    ret = (readbuf ? read (fd, readbuf, len)
+-	   : write (fd, writebuf, len));
++  if ((off_t) offset >= 0)
++    ret = (readbuf != nullptr
++	   ? pread64 (fd, readbuf, len, offset)
++	   : pwrite64 (fd, writebuf, len, offset));
++  else
+ #endif
++    {
++      ret = lseek (fd, offset, SEEK_SET);
++      if (ret != -1)
++	ret = (readbuf != nullptr
++	       ? read (fd, readbuf, len)
++	       : write (fd, writebuf, len));
++    }
+ 
+   if (ret == -1)
+     {
+--- a/gdbserver/linux-low.cc
++++ b/gdbserver/linux-low.cc
+@@ -5377,21 +5377,26 @@ proc_xfer_memory (CORE_ADDR memaddr, unsigned char *readbuf,
+     {
+       int bytes;
+ 
+-      /* If pread64 is available, use it.  It's faster if the kernel
+-	 supports it (only one syscall), and it's 64-bit safe even on
+-	 32-bit platforms (for instance, SPARC debugging a SPARC64
+-	 application).  */
++      /* Use pread64/pwrite64 if available, since they save a syscall
++	 and can handle 64-bit offsets even on 32-bit platforms (for
++	 instance, SPARC debugging a SPARC64 application).  But only
++	 use them if the offset isn't so high that when cast to off_t
++	 it'd be negative, as seen on SPARC64.  pread64/pwrite64
++	 outright reject such offsets.  lseek does not.  */
+ #ifdef HAVE_PREAD64
+-      bytes = (readbuf != nullptr
+-	       ? pread64 (fd, readbuf, len, memaddr)
+-	       : pwrite64 (fd, writebuf, len, memaddr));
+-#else
+-      bytes = -1;
+-      if (lseek (fd, memaddr, SEEK_SET) != -1)
++      if ((off_t) memaddr >= 0)
+ 	bytes = (readbuf != nullptr
+-		 ? read (fd, readbuf, len)
+-		 : write (fd, writebuf, len));
++		 ? pread64 (fd, readbuf, len, memaddr)
++		 : pwrite64 (fd, writebuf, len, memaddr));
++      else
+ #endif
++	{
++	  bytes = -1;
++	  if (lseek (fd, memaddr, SEEK_SET) != -1)
++	    bytes = (readbuf != nullptr
++		     ? read (fd, readbuf, len)
++		     : write (fd, writebuf, len));
++	}
+ 
+       if (bytes < 0)
+ 	return errno;
+-- 
+2.39.3
diff --git a/sys-devel/gdb/gdb-13.2-r1.ebuild b/sys-devel/gdb/gdb-13.2-r1.ebuild
new file mode 100644
index 000000000000..09dfedaf1ee1
--- /dev/null
+++ b/sys-devel/gdb/gdb-13.2-r1.ebuild
@@ -0,0 +1,313 @@
+# Copyright 1999-2023 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# See https://sourceware.org/gdb/wiki/DistroAdvice for general packaging
+# tips & notes.
+
+PYTHON_COMPAT=( python3_{10..11} )
+inherit flag-o-matic python-single-r1 strip-linguas toolchain-funcs
+
+export CTARGET=${CTARGET:-${CHOST}}
+
+if [[ ${CTARGET} == ${CHOST} ]] ; then
+	if [[ ${CATEGORY} == cross-* ]] ; then
+		export CTARGET=${CATEGORY#cross-}
+	fi
+fi
+
+is_cross() { [[ ${CHOST} != ${CTARGET} ]] ; }
+
+case ${PV} in
+	9999*)
+		# live git tree
+		EGIT_REPO_URI="https://sourceware.org/git/binutils-gdb.git"
+		inherit git-r3
+		SRC_URI=""
+		;;
+	*.*.50_p2???????|*.*.90_p2???????)
+		# Weekly snapshots
+		MY_PV="${PV/_p/.}"
+		SRC_URI="
+			https://sourceware.org/pub/gdb/snapshots/branch/gdb-weekly-${MY_PV}.tar.xz
+			https://sourceware.org/pub/gdb/snapshots/current/gdb-weekly-${MY_PV}.tar.xz
+			https://dev.gentoo.org/~sam/distfiles/${CATEGORY}/${PN}/gdb-weekly-${MY_PV}.tar.xz
+		"
+		S="${WORKDIR}/${PN}-${MY_PV}"
+
+		# e.g. 13.1.90_p20230325 is a snapshot on the stable branch, so it's fine
+		if [[ ${PV} == *.[123456789].9?_p2??????? ]] ; then
+			REGULAR_RELEASE=1
+		fi
+		;;
+	*.*.9?)
+		# Prereleases
+		MY_PV="${PV/_p/.}"
+		SRC_URI="
+			https://sourceware.org/pub/gdb/snapshots/branch/gdb-${MY_PV}.tar.xz
+			https://dev.gentoo.org/~sam/distfiles/${CATEGORY}/${PN}/gdb-${MY_PV}.tar.xz
+		"
+		S="${WORKDIR}/${PN}-${MY_PV}"
+		;;
+	*)
+		# Normal upstream release
+		SRC_URI="
+			mirror://gnu/gdb/${P}.tar.xz
+			https://sourceware.org/pub/gdb/releases/${P}.tar.xz
+		"
+
+		REGULAR_RELEASE=1
+esac
+
+PATCH_DEV=""
+PATCH_VER=""
+DESCRIPTION="GNU debugger"
+HOMEPAGE="https://sourceware.org/gdb/"
+SRC_URI="
+	${SRC_URI}
+	${PATCH_DEV:+https://dev.gentoo.org/~${PATCH_DEV}/distfiles/${CATEGORY}/${PN}/${P}-patches-${PATCH_VER}.tar.xz}
+	${PATCH_VER:+mirror://gentoo/${P}-patches-${PATCH_VER}.tar.xz}
+"
+
+LICENSE="GPL-3+ LGPL-2.1+"
+SLOT="0"
+IUSE="cet guile lzma multitarget nls +python +server sim source-highlight test vanilla xml xxhash zstd"
+if [[ -n ${REGULAR_RELEASE} ]] ; then
+	KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~x64-macos ~x64-solaris"
+fi
+REQUIRED_USE="python? ( ${PYTHON_REQUIRED_USE} )"
+RESTRICT="!test? ( test )"
+
+RDEPEND="
+	dev-libs/mpfr:=
+	dev-libs/gmp:=
+	>=sys-libs/ncurses-5.2-r2:=
+	>=sys-libs/readline-7:=
+	sys-libs/zlib
+	elibc_glibc? ( net-libs/libnsl:= )
+	lzma? ( app-arch/xz-utils )
+	python? ( ${PYTHON_DEPS} )
+	guile? ( >=dev-scheme/guile-2.0 )
+	xml? ( dev-libs/expat )
+	source-highlight? (
+		dev-util/source-highlight
+	)
+	xxhash? (
+		dev-libs/xxhash
+	)
+	zstd? ( app-arch/zstd:= )
+"
+DEPEND="${RDEPEND}"
+BDEPEND="
+	app-arch/xz-utils
+	sys-apps/texinfo
+	app-alternatives/yacc
+	nls? ( sys-devel/gettext )
+	source-highlight? ( virtual/pkgconfig )
+	test? ( dev-util/dejagnu )
+"
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-8.3.1-verbose-build.patch
+	"${FILESDIR}"/${P}-fix-sparc-debugging.patch
+)
+
+pkg_setup() {
+	use python && python-single-r1_pkg_setup
+}
+
+src_prepare() {
+	default
+
+	strip-linguas -u bfd/po opcodes/po
+
+	# Avoid using ancient termcap from host on Prefix systems
+	sed -i -e 's/termcap tinfow/tinfow/g' \
+		gdb/configure{.ac,} || die
+}
+
+gdb_branding() {
+	printf "Gentoo ${PV} "
+
+	if ! use vanilla && [[ -n ${PATCH_VER} ]] ; then
+		printf "p${PATCH_VER}"
+	else
+		printf "vanilla"
+	fi
+
+	[[ -n ${EGIT_COMMIT} ]] && printf " ${EGIT_COMMIT}"
+}
+
+src_configure() {
+	strip-unsupported-flags
+
+	# See https://www.gnu.org/software/make/manual/html_node/Parallel-Output.html
+	# Avoid really confusing logs from subconfigure spam, makes logs far
+	# more legible.
+	MAKEOPTS="--output-sync=line ${MAKEOPTS}"
+
+	local myconf=(
+		# portage's econf() does not detect presence of --d-d-t
+		# because it greps only top-level ./configure. But not
+		# gnulib's or gdb's configure.
+		--disable-dependency-tracking
+
+		--with-pkgversion="$(gdb_branding)"
+		--with-bugurl='https://bugs.gentoo.org/'
+		--disable-werror
+		# Disable modules that are in a combined binutils/gdb tree. bug #490566
+		--disable-{binutils,etc,gas,gold,gprof,gprofng,ld}
+
+		# avoid automagic dependency on (currently prefix) systems
+		# systems with debuginfod library, bug #754753
+		--without-debuginfod
+
+		$(use_enable test unit-tests)
+
+		# Allow user to opt into CET for host libraries.
+		# Ideally we would like automagic-or-disabled here.
+		# But the check does not quite work on i686: bug #760926.
+		$(use_enable cet)
+
+		# Helps when cross-compiling. Not to be confused with --with-sysroot.
+		--with-build-sysroot="${ESYSROOT}"
+	)
+
+	is_cross && myconf+=(
+		--with-sysroot="\${prefix}/${CTARGET}"
+		--includedir="\${prefix}/include/${CTARGET}"
+		--with-gdb-datadir="\${datadir}/gdb/${CTARGET}"
+	)
+
+	# gdbserver only works for native targets (CHOST==CTARGET).
+	# it also doesn't support all targets, so rather than duplicate
+	# the target list (which changes between versions), use the
+	# "auto" value when things are turned on, which is triggered
+	# whenever no --enable or --disable is given
+	if is_cross || use !server ; then
+		myconf+=( --disable-gdbserver )
+	fi
+
+	myconf+=(
+		--enable-64-bit-bfd
+		--disable-install-libbfd
+		--disable-install-libiberty
+		--enable-obsolete
+		# This only disables building in the readline subdir.
+		# For gdb itself, it'll use the system version.
+		--disable-readline
+		--with-system-readline
+		# This only disables building in the zlib subdir.
+		# For gdb itself, it'll use the system version.
+		--without-zlib
+		--with-system-zlib
+		--with-separate-debug-dir="${EPREFIX}"/usr/lib/debug
+		$(use_with xml expat)
+		$(use_with lzma)
+		$(use_enable nls)
+		$(use_enable sim)
+		$(use_enable source-highlight)
+		$(use multitarget && echo --enable-targets=all)
+		$(use_with python python "${EPYTHON}")
+		$(use_with xxhash)
+		$(use_with guile)
+		$(use_with zstd)
+
+		# Find libraries using the toolchain sysroot rather than the configured
+		# prefix. Needed when cross-compiling.
+		#
+		# Check which libraries to apply this to with:
+		# "${S}"/gdb/configure --help | grep without-lib | sort
+		--without-lib{babeltrace,expat,gmp,iconv,ipt,lzma,mpfr,xxhash}-prefix
+	)
+
+	# source-highlight is detected with pkg-config: bug #716558
+	export ac_cv_path_pkg_config_prog_path="$(tc-getPKG_CONFIG)"
+
+	export CC_FOR_BUILD="$(tc-getBUILD_CC)"
+
+	# ensure proper compiler is detected for Clang builds: bug #831202
+	export GCC_FOR_TARGET="${CC_FOR_TARGET:-$(tc-getCC)}"
+
+	econf "${myconf[@]}"
+}
+
+src_compile() {
+	emake V=1
+}
+
+src_test() {
+	# Run the unittests (nabbed invocation from Fedora's spec file) at least
+	emake -k -C gdb run GDBFLAGS='-batch -ex "maintenance selftest"'
+
+	# Too many failures
+	# In fact, gdb's test suite needs some work to get passing.
+	# See e.g. https://sourceware.org/gdb/wiki/TestingGDB.
+	# As of 11.2, on amd64: "# of unexpected failures    8600"
+	# Also, ia64 kernel crashes when gdb testsuite is running.
+	#emake -k check
+}
+
+src_install() {
+	emake V=1 DESTDIR="${D}" install
+
+	find "${ED}"/usr -name libiberty.a -delete || die
+
+	# Delete translations that conflict with binutils-libs. bug #528088
+	# Note: Should figure out how to store these in an internal gdb dir.
+	if use nls ; then
+		find "${ED}" \
+			-regextype posix-extended -regex '.*/(bfd|opcodes)[.]g?mo$' \
+			-delete || die
+	fi
+
+	# Don't install docs when building a cross-gdb
+	if [[ ${CTARGET} != ${CHOST} ]] ; then
+		rm -rf "${ED}"/usr/share/{doc,info,locale} || die
+		local f
+		for f in "${ED}"/usr/share/man/*/* ; do
+			if [[ ${f##*/} != ${CTARGET}-* ]] ; then
+				mv "${f}" "${f%/*}/${CTARGET}-${f##*/}" || die
+			fi
+		done
+		return 0
+	fi
+
+	# Install it by hand for now:
+	# https://sourceware.org/ml/gdb-patches/2011-12/msg00915.html
+	# Only install if it exists due to the twisted behavior (see
+	# notes in src_configure above).
+	[[ -e gdbserver/gdbreplay ]] && dobin gdbserver/gdbreplay
+
+	docinto gdb
+	dodoc gdb/CONTRIBUTE gdb/README gdb/MAINTAINERS \
+		gdb/NEWS gdb/PROBLEMS
+	docinto sim
+	dodoc sim/{MAINTAINERS,README-HACKING}
+
+	if use server ; then
+		docinto gdbserver
+		dodoc gdbserver/README
+	fi
+
+	# Remove shared info pages
+	rm -f "${ED}"/usr/share/info/{annotate,bfd,configure,ctf-spec,standards}.info*
+
+	if use python ; then
+		python_optimize "${ED}"/usr/share/gdb/python/gdb
+	fi
+}
+
+pkg_postinst() {
+	# Portage doesn't unmerge files in /etc
+	rm -vf "${EROOT}"/etc/skel/.gdbinit
+
+	if use prefix && [[ ${CHOST} == *-darwin* ]] ; then
+		ewarn "gdb is unable to get a mach task port when installed by Prefix"
+		ewarn "Portage, unprivileged.  To make gdb fully functional you'll"
+		ewarn "have to perform the following steps:"
+		ewarn "  % sudo chgrp procmod ${EPREFIX}/usr/bin/gdb"
+		ewarn "  % sudo chmod g+s ${EPREFIX}/usr/bin/gdb"
+	fi
+}