X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fnios2-linux-tdep.c;h=345dfeb9235ed56bf52581df7cf001ffcd5f22cd;hb=bd920864f3dc2cad376989a642ab774aef6b2fce;hp=b2a3c3e20a336cc1f3e156f2e0706cf447404c3f;hpb=6d3d12ebef6fa7dd6bc8c34fbc5e440ac8d0a8c6;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/nios2-linux-tdep.c b/gdb/nios2-linux-tdep.c index b2a3c3e20a..345dfeb923 100644 --- a/gdb/nios2-linux-tdep.c +++ b/gdb/nios2-linux-tdep.c @@ -1,5 +1,5 @@ /* Target-dependent code for GNU/Linux on Nios II. - Copyright (C) 2012-2014 Free Software Foundation, Inc. + Copyright (C) 2012-2020 Free Software Foundation, Inc. Contributed by Mentor Graphics, Inc. This file is part of GDB. @@ -29,8 +29,7 @@ #include "linux-tdep.h" #include "glibc-tdep.h" #include "nios2-tdep.h" - -#include "features/nios2-linux.c" +#include "gdbarch.h" /* Core file and register set support. */ @@ -49,6 +48,11 @@ static const int reg_offsets[NIOS2_NUM_REGS] = -1, -1, -1, -1, -1, -1, -1, -1 }; +/* General register set size. Should match sizeof (struct pt_regs) + + sizeof (struct switch_stack) from the NIOS2 Linux kernel patch. */ + +#define NIOS2_GREGS_SIZE (4 * 34) + /* Implement the supply_regset hook for core files. */ static void @@ -56,7 +60,7 @@ nios2_supply_gregset (const struct regset *regset, struct regcache *regcache, int regnum, const void *gregs_buf, size_t len) { - const gdb_byte *gregs = gregs_buf; + const gdb_byte *gregs = (const gdb_byte *) gregs_buf; int regno; static const gdb_byte zero_buf[4] = {0, 0, 0, 0}; @@ -64,10 +68,27 @@ nios2_supply_gregset (const struct regset *regset, if (regnum == -1 || regnum == regno) { if (reg_offsets[regno] != -1) - regcache_raw_supply (regcache, regno, - gregs + 4 * reg_offsets[regno]); + regcache->raw_supply (regno, gregs + 4 * reg_offsets[regno]); else - regcache_raw_supply (regcache, regno, zero_buf); + regcache->raw_supply (regno, zero_buf); + } +} + +/* Implement the collect_regset hook for core files. */ + +static void +nios2_collect_gregset (const struct regset *regset, + const struct regcache *regcache, + int regnum, void *gregs_buf, size_t len) +{ + gdb_byte *gregs = (gdb_byte *) gregs_buf; + int regno; + + for (regno = NIOS2_Z_REGNUM; regno <= NIOS2_MPUACC_REGNUM; regno++) + if (regnum == -1 || regnum == regno) + { + if (reg_offsets[regno] != -1) + regcache->raw_collect (regno, gregs + 4 * reg_offsets[regno]); } } @@ -75,23 +96,41 @@ static const struct regset nios2_core_regset = { NULL, nios2_supply_gregset, - NULL, + nios2_collect_gregset }; -/* Implement the regset_from_core_section gdbarch method. */ +/* Iterate over core file register note sections. */ -static const struct regset * -nios2_regset_from_core_section (struct gdbarch *gdbarch, - const char *sect_name, size_t sect_size) +static void +nios2_iterate_over_regset_sections (struct gdbarch *gdbarch, + iterate_over_regset_sections_cb *cb, + void *cb_data, + const struct regcache *regcache) { - if (strcmp (sect_name, ".reg") == 0) - return &nios2_core_regset; - - return NULL; + cb (".reg", NIOS2_GREGS_SIZE, NIOS2_GREGS_SIZE, &nios2_core_regset, NULL, + cb_data); } /* Initialize a trad-frame cache corresponding to the tramp-frame. - FUNC is the address of the instruction TRAMP[0] in memory. */ + FUNC is the address of the instruction TRAMP[0] in memory. + + This ABI is not documented. It corresponds to rt_setup_ucontext in + the kernel arch/nios2/kernel/signal.c file. + + The key points are: + - The kernel creates a trampoline at the hard-wired address 0x1044. + - The stack pointer points to an object of type struct rt_sigframe. + The definition of this structure is not exported from the kernel. + The register save area is located at offset 152 bytes (as determined + by inspection of the stack contents in the debugger), and the + registers are saved as r1-r23, ra, fp, gp, ea, sp. + + This interface was implemented with kernel version 3.19 (the first + official mainline kernel). Older unofficial kernel versions used + incompatible conventions; we do not support those here. */ + +#define NIOS2_SIGRETURN_TRAMP_ADDR 0x1044 +#define NIOS2_SIGRETURN_REGSAVE_OFFSET 152 static void nios2_linux_rt_sigreturn_init (const struct tramp_frame *self, @@ -99,7 +138,8 @@ nios2_linux_rt_sigreturn_init (const struct tramp_frame *self, struct trad_frame_cache *this_cache, CORE_ADDR func) { - CORE_ADDR base = func + 41 * 4; + CORE_ADDR sp = get_frame_register_unsigned (next_frame, NIOS2_SP_REGNUM); + CORE_ADDR base = sp + NIOS2_SIGRETURN_REGSAVE_OFFSET; int i; for (i = 0; i < 23; i++) @@ -114,13 +154,30 @@ nios2_linux_rt_sigreturn_init (const struct tramp_frame *self, trad_frame_set_id (this_cache, frame_id_build (base, func)); } -static struct tramp_frame nios2_linux_rt_sigreturn_tramp_frame = +/* Trampoline for sigreturn. This has the form + movi r2, __NR_rt_sigreturn + trap 0 + appropriately encoded for R1 or R2. */ + +static struct tramp_frame nios2_r1_linux_rt_sigreturn_tramp_frame = { SIGTRAMP_FRAME, 4, { - { 0x00800004 | (139 << 6), -1 }, /* movi r2,__NR_rt_sigreturn */ - { 0x003b683a, -1 }, /* trap */ + { MATCH_R1_MOVI | SET_IW_I_B (2) | SET_IW_I_IMM16 (139), ULONGEST_MAX }, + { MATCH_R1_TRAP | SET_IW_R_IMM5 (0), ULONGEST_MAX}, + { TRAMP_SENTINEL_INSN } + }, + nios2_linux_rt_sigreturn_init +}; + +static struct tramp_frame nios2_r2_linux_rt_sigreturn_tramp_frame = +{ + SIGTRAMP_FRAME, + 4, + { + { MATCH_R2_MOVI | SET_IW_F2I16_B (2) | SET_IW_F2I16_IMM16 (139), ULONGEST_MAX }, + { MATCH_R2_TRAP | SET_IW_X2L5_IMM5 (0), ULONGEST_MAX}, { TRAMP_SENTINEL_INSN } }, nios2_linux_rt_sigreturn_init @@ -130,7 +187,8 @@ static struct tramp_frame nios2_linux_rt_sigreturn_tramp_frame = instruction to be executed. */ static CORE_ADDR -nios2_linux_syscall_next_pc (struct frame_info *frame) +nios2_linux_syscall_next_pc (struct frame_info *frame, + const struct nios2_opcode *op) { CORE_ADDR pc = get_frame_pc (frame); ULONGEST syscall_nr = get_frame_register_unsigned (frame, NIOS2_R2_REGNUM); @@ -140,7 +198,18 @@ nios2_linux_syscall_next_pc (struct frame_info *frame) if (syscall_nr == 139 /* rt_sigreturn */) return frame_unwind_caller_pc (frame); - return pc + NIOS2_OPCODE_SIZE; + return pc + op->size; +} + +/* Return true if PC is a kernel helper, a function mapped by the kernel + into user space on an unwritable page. Currently the only such function + is __kuser_cmpxchg at 0x1004. See arch/nios2/kernel/entry.S in the Linux + kernel sources and sysdeps/unix/sysv/linux/nios2/atomic-machine.h in + GLIBC. */ +static bool +nios2_linux_is_kernel_helper (CORE_ADDR pc) +{ + return pc == 0x1004; } /* Hook function for gdbarch_register_osabi. */ @@ -162,27 +231,33 @@ nios2_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) set_gdbarch_fetch_tls_load_module_address (gdbarch, svr4_fetch_objfile_link_map); /* Core file support. */ - set_gdbarch_regset_from_core_section (gdbarch, - nios2_regset_from_core_section); + set_gdbarch_iterate_over_regset_sections + (gdbarch, nios2_iterate_over_regset_sections); /* Linux signal frame unwinders. */ - tramp_frame_prepend_unwinder (gdbarch, - &nios2_linux_rt_sigreturn_tramp_frame); + if (gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_nios2r2) + tramp_frame_prepend_unwinder (gdbarch, + &nios2_r2_linux_rt_sigreturn_tramp_frame); + else + tramp_frame_prepend_unwinder (gdbarch, + &nios2_r1_linux_rt_sigreturn_tramp_frame); tdep->syscall_next_pc = nios2_linux_syscall_next_pc; + tdep->is_kernel_helper = nios2_linux_is_kernel_helper; /* Index of target address word in glibc jmp_buf. */ tdep->jb_pc = 10; } -/* Provide a prototype to silence -Wmissing-prototypes. */ - -extern initialize_file_ftype _initialize_nios2_linux_tdep; - +void _initialize_nios2_linux_tdep (); void -_initialize_nios2_linux_tdep (void) +_initialize_nios2_linux_tdep () { - gdbarch_register_osabi (bfd_arch_nios2, 0, GDB_OSABI_LINUX, - nios2_linux_init_abi); - initialize_tdesc_nios2_linux (); + const struct bfd_arch_info *arch_info; + + for (arch_info = bfd_lookup_arch (bfd_arch_nios2, 0); + arch_info != NULL; + arch_info = arch_info->next) + gdbarch_register_osabi (bfd_arch_nios2, arch_info->mach, + GDB_OSABI_LINUX, nios2_linux_init_abi); }