Xfer:siginfo:read query is received, usually, when GDB catches a signal and needs additional info about it, like the si_code and the si_addr, so GDB can show the user interesting info about the signal. This query can also be received when an user explicitly asks for more information via printing GBD's special purpose variable '$_siginfo'.
This series adds the stub to handle Xfer:siginfo:read queries. To achieve this, it is first necessary to stash the target-specific siginfo in the gdbstub server state struct when handling a signal, so it requires modifying the gdb_handlesig function to accept the target's siginfo struct and its length. Later, when replying to a Xfer:siginfo:read query (i.e., after a signal is caught), the query handler utilizes the stashed siginfo to form the packet for replying to the query. Finally, a test is added to check if the stub correctly responds to the query when a simple binary causes a SIGSEGV. Since the si_addr must be available in the case of a SIGSEGV, the value of si_addr is checked against the expected faulting address, corresponding to the dereferenced pointer value in the binary. v1: https://lists.gnu.org/archive/html/qemu-devel/2024-03/msg00423.html v2: https://lists.gnu.org/archive/html/qemu-devel/2024-03/msg01858.html Cheers, Gustavo Gustavo Romero (5): gdbstub: Rename back gdb_handlesig linux-user: Move tswap_siginfo out of target code gdbstub: Save target's siginfo gdbstub: Add Xfer:siginfo:read stub tests/tcg: Add multiarch test for Xfer:siginfo:read stub bsd-user/main.c | 2 +- bsd-user/signal.c | 5 +- gdbstub/gdbstub.c | 8 ++++ gdbstub/internals.h | 1 + gdbstub/user.c | 46 +++++++++++++++++-- include/gdbstub/user.h | 19 +++----- linux-user/aarch64/signal.c | 2 +- linux-user/alpha/signal.c | 2 +- linux-user/arm/signal.c | 2 +- linux-user/hexagon/signal.c | 2 +- linux-user/hppa/signal.c | 2 +- linux-user/i386/signal.c | 6 +-- linux-user/loongarch64/signal.c | 2 +- linux-user/m68k/signal.c | 4 +- linux-user/main.c | 2 +- linux-user/microblaze/signal.c | 2 +- linux-user/mips/signal.c | 4 +- linux-user/nios2/signal.c | 2 +- linux-user/openrisc/signal.c | 2 +- linux-user/ppc/signal.c | 4 +- linux-user/riscv/signal.c | 2 +- linux-user/s390x/signal.c | 2 +- linux-user/sh4/signal.c | 2 +- linux-user/signal-common.h | 2 - linux-user/signal.c | 15 ++++-- linux-user/sparc/signal.c | 2 +- linux-user/xtensa/signal.c | 2 +- tests/tcg/multiarch/Makefile.target | 10 +++- .../gdbstub/test-qxfer-siginfo-read.py | 26 +++++++++++ tests/tcg/multiarch/segfault.c | 14 ++++++ 30 files changed, 147 insertions(+), 49 deletions(-) create mode 100644 tests/tcg/multiarch/gdbstub/test-qxfer-siginfo-read.py create mode 100644 tests/tcg/multiarch/segfault.c -- 2.34.1
