X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Fi386-linux-tdep.c;h=7b69aab3a161a024389cd11a56e0883e63603213;hb=0002ad5f4575ad8f85bac2989ce4e1e8b99c905b;hp=673dbfdbce84366d3a0eca11da0d78cf51fb4fcc;hpb=7b6bb8daaceb9ecf3f42dea57ae82733d6a3b2f6;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c index 673dbfdbce..7b69aab3a1 100644 --- a/gdb/i386-linux-tdep.c +++ b/gdb/i386-linux-tdep.c @@ -1,7 +1,6 @@ /* Target-dependent code for GNU/Linux i386. - Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, - 2011 Free Software Foundation, Inc. + Copyright (C) 2000-2013 Free Software Foundation, Inc. This file is part of GDB. @@ -45,7 +44,7 @@ /* The syscall's XML filename for i386. */ #define XML_SYSCALL_FILENAME_I386 "syscalls/i386-linux.xml" -#include "record.h" +#include "record-full.h" #include "linux-record.h" #include @@ -255,7 +254,7 @@ static int i386_linux_sigtramp_p (struct frame_info *this_frame) { CORE_ADDR pc = get_frame_pc (this_frame); - char *name; + const char *name; find_pc_partial_function (pc, &name, NULL, NULL); @@ -280,7 +279,7 @@ i386_linux_dwarf_signal_frame_p (struct gdbarch *gdbarch, struct frame_info *this_frame) { CORE_ADDR pc = get_frame_pc (this_frame); - char *name; + const char *name; find_pc_partial_function (pc, &name, NULL, NULL); @@ -371,23 +370,23 @@ i386_linux_write_pc (struct regcache *regcache, CORE_ADDR pc) static int i386_all_but_ip_registers_record (struct regcache *regcache) { - if (record_arch_list_add_reg (regcache, I386_EAX_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_EAX_REGNUM)) return -1; - if (record_arch_list_add_reg (regcache, I386_ECX_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_ECX_REGNUM)) return -1; - if (record_arch_list_add_reg (regcache, I386_EDX_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_EDX_REGNUM)) return -1; - if (record_arch_list_add_reg (regcache, I386_EBX_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_EBX_REGNUM)) return -1; - if (record_arch_list_add_reg (regcache, I386_ESP_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_ESP_REGNUM)) return -1; - if (record_arch_list_add_reg (regcache, I386_EBP_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_EBP_REGNUM)) return -1; - if (record_arch_list_add_reg (regcache, I386_ESI_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_ESI_REGNUM)) return -1; - if (record_arch_list_add_reg (regcache, I386_EDI_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_EDI_REGNUM)) return -1; - if (record_arch_list_add_reg (regcache, I386_EFLAGS_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_EFLAGS_REGNUM)) return -1; return 0; @@ -419,7 +418,7 @@ i386_canonicalize_syscall (int syscall) static struct linux_record_tdep i386_linux_record_tdep; static int -i386_linux_intx80_sysenter_record (struct regcache *regcache) +i386_linux_intx80_sysenter_syscall_record (struct regcache *regcache) { int ret; LONGEST syscall_native; @@ -451,7 +450,7 @@ i386_linux_intx80_sysenter_record (struct regcache *regcache) return ret; /* Record the return value of the system call. */ - if (record_arch_list_add_reg (regcache, I386_EAX_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_EAX_REGNUM)) return -1; return 0; @@ -460,17 +459,17 @@ i386_linux_intx80_sysenter_record (struct regcache *regcache) #define I386_LINUX_xstate 270 #define I386_LINUX_frame_size 732 -int +static int i386_linux_record_signal (struct gdbarch *gdbarch, struct regcache *regcache, - enum target_signal signal) + enum gdb_signal signal) { ULONGEST esp; if (i386_all_but_ip_registers_record (regcache)) return -1; - if (record_arch_list_add_reg (regcache, I386_EIP_REGNUM)) + if (record_full_arch_list_add_reg (regcache, I386_EIP_REGNUM)) return -1; /* Record the change in the stack. */ @@ -481,22 +480,28 @@ i386_linux_record_signal (struct gdbarch *gdbarch, /* This is for frame_size. sp -= sizeof (struct rt_sigframe); */ esp -= I386_LINUX_frame_size; - if (record_arch_list_add_mem (esp, - I386_LINUX_xstate + I386_LINUX_frame_size)) + if (record_full_arch_list_add_mem (esp, + I386_LINUX_xstate + I386_LINUX_frame_size)) return -1; - if (record_arch_list_add_end ()) + if (record_full_arch_list_add_end ()) return -1; return 0; } +/* Core of the implementation for gdbarch get_syscall_number. Get pending + syscall number from REGCACHE. If there is no pending syscall -1 will be + returned. Pending syscall means ptrace has stepped into the syscall but + another ptrace call will step out. PC is right after the int $0x80 + / syscall / sysenter instruction in both cases, PC does not change during + the second ptrace step. */ + static LONGEST -i386_linux_get_syscall_number (struct gdbarch *gdbarch, - ptid_t ptid) +i386_linux_get_syscall_number_from_regcache (struct regcache *regcache) { - struct regcache *regcache = get_thread_regcache (ptid); + struct gdbarch *gdbarch = get_regcache_arch (regcache); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); /* The content of a register. */ gdb_byte buf[4]; @@ -513,6 +518,18 @@ i386_linux_get_syscall_number (struct gdbarch *gdbarch, return ret; } +/* Wrapper for i386_linux_get_syscall_number_from_regcache to make it + compatible with gdbarch get_syscall_number method prototype. */ + +static LONGEST +i386_linux_get_syscall_number (struct gdbarch *gdbarch, + ptid_t ptid) +{ + struct regcache *regcache = get_thread_regcache (ptid); + + return i386_linux_get_syscall_number_from_regcache (regcache); +} + /* The register sets used in GNU/Linux ELF core-dumps are identical to the register sets in `struct user' that are used for a.out core-dumps. These are also used by ptrace(2). The corresponding @@ -582,8 +599,7 @@ static int i386_linux_sc_reg_offset[] = /* Get XSAVE extended state xcr0 from core dump. */ uint64_t -i386_linux_core_read_xcr0 (struct gdbarch *gdbarch, - struct target_ops *target, bfd *abfd) +i386_linux_core_read_xcr0 (bfd *abfd) { asection *xstate = bfd_get_section_by_name (abfd, ".reg-xstate"); uint64_t xcr0; @@ -603,7 +619,8 @@ i386_linux_core_read_xcr0 (struct gdbarch *gdbarch, I386_LINUX_XSAVE_XCR0_OFFSET, 8)) { - warning (_("Couldn't read `xcr0' bytes from `.reg-xstate' section in core file.")); + warning (_("Couldn't read `xcr0' bytes from " + "`.reg-xstate' section in core file.")); return 0; } @@ -624,7 +641,7 @@ i386_linux_core_read_description (struct gdbarch *gdbarch, bfd *abfd) { /* Linux/i386. */ - uint64_t xcr0 = i386_linux_core_read_xcr0 (gdbarch, target, abfd); + uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd); switch ((xcr0 & I386_XSTATE_AVX_MASK)) { case I386_XSTATE_AVX_MASK: @@ -643,6 +660,49 @@ i386_linux_core_read_description (struct gdbarch *gdbarch, return tdesc_i386_mmx_linux; } +/* Linux kernel shows PC value after the 'int $0x80' instruction even if + inferior is still inside the syscall. On next PTRACE_SINGLESTEP it will + finish the syscall but PC will not change. + + Some vDSOs contain 'int $0x80; ret' and during stepping out of the syscall + i386_displaced_step_fixup would keep PC at the displaced pad location. + As PC is pointing to the 'ret' instruction before the step + i386_displaced_step_fixup would expect inferior has just executed that 'ret' + and PC should not be adjusted. In reality it finished syscall instead and + PC should get relocated back to its vDSO address. Hide the 'ret' + instruction by 'nop' so that i386_displaced_step_fixup is not confused. + + It is not fully correct as the bytes in struct displaced_step_closure will + not match the inferior code. But we would need some new flag in + displaced_step_closure otherwise to keep the state that syscall is finishing + for the later i386_displaced_step_fixup execution as the syscall execution + is already no longer detectable there. The new flag field would mean + i386-linux-tdep.c needs to wrap all the displacement methods of i386-tdep.c + which does not seem worth it. The same effect is achieved by patching that + 'nop' instruction there instead. */ + +static struct displaced_step_closure * +i386_linux_displaced_step_copy_insn (struct gdbarch *gdbarch, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs) +{ + struct displaced_step_closure *closure; + + closure = i386_displaced_step_copy_insn (gdbarch, from, to, regs); + + if (i386_linux_get_syscall_number_from_regcache (regs) != -1) + { + /* Since we use simple_displaced_step_copy_insn, our closure is a + copy of the instruction. */ + gdb_byte *insn = (gdb_byte *) closure; + + /* Fake nop. */ + insn[0] = 0x90; + } + + return closure; +} + static void i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { @@ -856,11 +916,12 @@ i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) i386_linux_record_tdep.arg5 = I386_EDI_REGNUM; i386_linux_record_tdep.arg6 = I386_EBP_REGNUM; - tdep->i386_intx80_record = i386_linux_intx80_sysenter_record; - tdep->i386_sysenter_record = i386_linux_intx80_sysenter_record; + tdep->i386_intx80_record = i386_linux_intx80_sysenter_syscall_record; + tdep->i386_sysenter_record = i386_linux_intx80_sysenter_syscall_record; + tdep->i386_syscall_record = i386_linux_intx80_sysenter_syscall_record; /* N_FUN symbols in shared libaries have 0 for their values and need - to be relocated. */ + to be relocated. */ set_gdbarch_sofun_address_maybe_missing (gdbarch, 1); /* GNU/Linux uses SVR4-style shared libraries. */ @@ -890,7 +951,7 @@ i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) /* Displaced stepping. */ set_gdbarch_displaced_step_copy_insn (gdbarch, - i386_displaced_step_copy_insn); + i386_linux_displaced_step_copy_insn); set_gdbarch_displaced_step_fixup (gdbarch, i386_displaced_step_fixup); set_gdbarch_displaced_step_free_closure (gdbarch, simple_displaced_step_free_closure); @@ -914,7 +975,7 @@ _initialize_i386_linux_tdep (void) gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_LINUX, i386_linux_init_abi); - /* Initialize the Linux target description */ + /* Initialize the Linux target description. */ initialize_tdesc_i386_linux (); initialize_tdesc_i386_mmx_linux (); initialize_tdesc_i386_avx_linux ();