Merge tag 'pull-lu-20241105' of https://gitlab.com/rth7680/qemu into staging

tests/tcg: Replace -mpower8-vector with -mcpu=power8
linux-user: Fix GDB complaining about system-supplied DSO string tab

Merge tag 'pull-lu-20241105' of https://gitlab.com/rth7680/qemu into staging

tests/tcg: Replace -mpower8-vector with -mcpu=power8
linux-user: Fix GDB complaining about system-supplied DSO string table index
linux-user: Allow custom rt signal mappings

# -----BEGIN PGP SIGNATURE-----
#
# iQFRBAABCgA7FiEEekgeeIaLTbaoWgXAZN846K9+IV8FAmcqM2wdHHJpY2hhcmQu
# aGVuZGVyc29uQGxpbmFyby5vcmcACgkQZN846K9+IV86KQgAhR1OmVAhPYTJiYH6
# Bhp9s+PbdFw/UbxConf9+WFoa/vM1x/QvX1ybzNDl9aOeiH9RIX4hFWUH5WR8xu+
# gZrzplHDcsrUEs5Q7/GWGJaCbd92Rn6g5wcXyoVebMaVP1g/m+NJoxo2XOpZvY06
# G0BcNj4Ib/D0FgkgZrUJcf3DBWaW/9WCd17fBXLo1bpahdKvqV4PbmhhH+QZCVXr
# GHg03F+/35U85kNVnPcUg4PJARQHdK4ZmfE4etgGvVkTdS8r43qfO1nMT0ul8aOD
# uATdMQrbwKA0XLjWVOVxe4165c+luHpUweKNgiOie+s849YUM3TsFpunKoPBIEpQ
# Gu0ejw==
# =wipF
# -----END PGP SIGNATURE-----
# gpg: Signature made Tue 05 Nov 2024 15:02:04 GMT
# gpg: using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg: issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A 05C0 64DF 38E8 AF7E 215F

* tag 'pull-lu-20241105' of https://gitlab.com/rth7680/qemu:
tests/tcg: Add SIGRTMIN/SIGRTMAX test
linux-user: Allow custom rt signal mappings
linux-user: Fix GDB complaining about system-supplied DSO string table index
tests/tcg: Replace -mpower8-vector with -mcpu=power8

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

linux-user: Fix GDB complaining about system-supplied DSO string table index

When debugging qemu-user processes using gdbstub, the following warning
appears every time:

warning: BFD: warning: s

linux-user: Fix GDB complaining about system-supplied DSO string table index

When debugging qemu-user processes using gdbstub, the following warning
appears every time:

warning: BFD: warning: system-supplied DSO at 0x7f8253cc3000 has a corrupt string table index

The reason is that QEMU does not map the VDSO's section headers. The
VDSO's ELF header's e_shoff points to zeros, which GDB fails to parse.

The difference with the kernel's VDSO is that the latter is mapped as a
blob, ignoring program headers - which also don't cover the section
table. QEMU, on the other hand, loads it as an ELF file.

There appears to be no way to place section headers inside a section,
and, therefore, no way to refer to them from a linker script. Also, ld
hardcodes section headers to be non-loadable, see
_bfd_elf_assign_file_positions_for_non_load(). In theory ld could be
enhanced by implementing an "SHDRS" keyword in addition to the existing
"FILEHDR" and "PHDRS".

There are multiple ways to resolve the issue:

- Copy VDSO as a blob in load_elf_vdso(). This would require creating
specialized loader logic, that duplicates parts of load_elf_image().

- Fix up VDSO's PHDR size in load_elf_vdso(). This would require either
duplicating the parsing logic, or adding an ugly parameter to
load_elf_image().

- Fix up VDSO's PHDR size in gen-vdso. This is the simplest solution,
so do it.

There are two tricky parts:

- Byte-swaps need to be done either on local copies, or in-place and
then reverted in the end. To preserve the existing code structure, do
the former for Sym and Dyn, and the latter for Ehdr, Phdr, and Shdr.

- There must be no .bss, which is already the case - but having an
explicit check is helpful to ensure correctness.

To verify this change, I diffed the on-disk and the loaded VDSOs; the
result does not show anything unusual, except for what seems to be an
existing oversight (which should probably be fixed separately):

│ Symbol table '.dynsym' contains 8 entries:
│ Num: Value Size Type Bind Vis Ndx Name
│ - 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
│ - 6: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LINUX_2.6.29
│ + 0: 00007f61075bf000 0 NOTYPE LOCAL DEFAULT UND
│ + 6: 00007f61075bf000 0 OBJECT GLOBAL DEFAULT ABS LINUX_2.6.29

Fixes: 2fa536d10797 ("linux-user: Add gen-vdso tool")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20241023202850.55211-1-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

show more ...

Merge tag 'pull-lu-20231030' of https://gitlab.com/rth7680/qemu into staging

linux-user: Fix guest signal remapping after adjusting SIGABRT
linux-user: Implement VDSOs

* tag 'pull-lu-20231030' of h

Merge tag 'pull-lu-20231030' of https://gitlab.com/rth7680/qemu into staging

linux-user: Fix guest signal remapping after adjusting SIGABRT
linux-user: Implement VDSOs

* tag 'pull-lu-20231030' of https://gitlab.com/rth7680/qemu: (21 commits)
build: Add update-linux-vdso makefile rule
linux-user: Show vdso address in /proc/pid/maps
linux-user/s390x: Add vdso
linux-user/s390x: Rename __SIGNAL_FRAMESIZE to STACK_FRAME_OVERHEAD
linux-user/ppc: Add vdso
linux-user/loongarch64: Add vdso
linux-user/riscv: Add vdso
linux-user/hppa: Add vdso
linux-user/arm: Add vdso
linux-user/aarch64: Add vdso
linux-user/x86_64: Add vdso
linux-user/i386: Add vdso
linux-user: Add gen-vdso tool
linux-user: Load vdso image if available
linux-user: Replace bprm->fd with bprm->src.fd
linux-user: Use ImageSource in load_symbols
linux-user: Use ImageSource in load_elf_image
linux-user: Do not clobber bprm_buf swapping ehdr
linux-user: Tidy loader_exec
linux-user: Introduce imgsrc_read, imgsrc_read_alloc
...

Conflicts:
linux-user/arm/signal.c
Fix an #include context conflict.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

show more ...

linux-user: Add gen-vdso tool

This tool will be used for post-processing the linked vdso image,
turning it into something that is easy to include into elfload.c.

Reviewed-by: Philippe Mathieu-Daudé

linux-user: Add gen-vdso tool

This tool will be used for post-processing the linked vdso image,
turning it into something that is easy to include into elfload.c.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

show more ...