From be908bd6e7fdcf0b91b949b152a063b5791856b5 Mon Sep 17 00:00:00 2001 From: Tiezhu Yang Date: Wed, 31 Jan 2024 16:10:30 +0800 Subject: [PATCH] gdb: LoongArch: Implement the get_syscall_number gdbarch method In the current code, the feature 'catch syscall' is not supported on LoongArch, implement the "get_syscall_number" gdbarch method to get the system call number from the register a7. Without this patch: (gdb) catch syscall The feature 'catch syscall' is not supported on this architecture yet. Signed-off-by: Tiezhu Yang --- gdb/loongarch-linux-tdep.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/gdb/loongarch-linux-tdep.c b/gdb/loongarch-linux-tdep.c index 0e82c09b4ff..f1471d53ff4 100644 --- a/gdb/loongarch-linux-tdep.c +++ b/gdb/loongarch-linux-tdep.c @@ -534,6 +534,31 @@ loongarch_linux_syscall_next_pc (frame_info_ptr frame) return pc + 4; } +/* Implement the "get_syscall_number" gdbarch method. */ + +static LONGEST +loongarch_linux_get_syscall_number (struct gdbarch *gdbarch, thread_info *thread) +{ + struct regcache *regcache = get_thread_regcache (thread); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int regsize = register_size (gdbarch, LOONGARCH_A7_REGNUM); + /* The content of a register. */ + gdb_byte buf[8]; + /* The result. */ + LONGEST ret; + + gdb_assert (regsize <= sizeof (buf)); + + /* Getting the system call number from the register. + When dealing with the LoongArch architecture, this information + is stored at the a7 register. */ + regcache->cooked_read (LOONGARCH_A7_REGNUM, buf); + + ret = extract_signed_integer (buf, regsize, byte_order); + + return ret; +} + /* Initialize LoongArch Linux ABI info. */ static void @@ -564,6 +589,9 @@ loongarch_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) set_gdbarch_iterate_over_regset_sections (gdbarch, loongarch_iterate_over_regset_sections); tdep->syscall_next_pc = loongarch_linux_syscall_next_pc; + + /* Get the syscall number from the arch's register. */ + set_gdbarch_get_syscall_number (gdbarch, loongarch_linux_get_syscall_number); } /* Initialize LoongArch Linux target support. */ -- 2.39.5