| From bfee93403b46ae4f050282b7721ba39073905c69 Mon Sep 17 00:00:00 2001 |
| From: Anton Kolesov <Anton.Kolesov@synopsys.com> |
| Date: Mon, 22 Aug 2016 19:39:46 +0300 |
| Subject: [PATCH 1/4] arc: Add support for signal handlers |
| |
| This patch adds the necessary infrastructure to handle signal frames for |
| ARC architecture. It is fairly similar to what any other architecture |
| would have. Linux specific parts will be in a separate patch. |
| |
| v2 [1]: |
| - Make the logic of "arc_sigtramp_frame_sniffer ()" simpler. |
| |
| [1] Tom's remark for the first version |
| https://sourceware.org/pipermail/gdb-patches/2020-November/173221.html |
| |
| gdb/ChangeLog: |
| |
| * arc-tdep.c (arc_make_sigtramp_frame_cache): New function. |
| (arc_sigtramp_frame_this_id): Likewise. |
| (arc_sigtramp_frame_prev_register): Likewise. |
| (arc_sigtramp_frame_sniffer): Likewise. |
| (arc_siftramp_frame_unwind): New global variable. |
| (arc_gdbarch_init): Use sigtramp capabilities. |
| (arc_dump_tdep): Print sigtramp fields. |
| * arc-tdep.h (gdbarch_tdep): Add sigtramp fields. |
| |
| Upstream-Status: Backport [https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=b4e3cd0440109d0a5552d3313ccbd35c8103335b] |
| |
| Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com> |
| Signed-off-by: Shahab Vahedi <shahab@synopsys.com> |
| Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> |
| --- |
| gdb/arc-tdep.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| gdb/arc-tdep.h | 13 ++++++ |
| 2 files changed, 136 insertions(+) |
| |
| diff --git a/gdb/arc-tdep.c b/gdb/arc-tdep.c |
| index 93e2fd88a9a..3356252525d 100644 |
| --- a/gdb/arc-tdep.c |
| +++ b/gdb/arc-tdep.c |
| @@ -1843,6 +1843,104 @@ arc_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum, |
| reg->how = DWARF2_FRAME_REG_CFA; |
| } |
| |
| +/* Signal trampoline frame unwinder. Allows frame unwinding to happen |
| + from within signal handlers. */ |
| + |
| +static struct arc_frame_cache * |
| +arc_make_sigtramp_frame_cache (struct frame_info *this_frame) |
| +{ |
| + if (arc_debug) |
| + debug_printf ("arc: sigtramp_frame_cache\n"); |
| + |
| + struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); |
| + |
| + /* Allocate new frame cache instance and space for saved register info. */ |
| + struct arc_frame_cache *cache = FRAME_OBSTACK_ZALLOC (struct arc_frame_cache); |
| + cache->saved_regs = trad_frame_alloc_saved_regs (this_frame); |
| + |
| + /* Get the stack pointer and use it as the frame base. */ |
| + cache->prev_sp = arc_frame_base_address (this_frame, NULL); |
| + |
| + /* If the ARC-private target-dependent info doesn't have a table of |
| + offsets of saved register contents within an OS signal context |
| + structure, then there is nothing to analyze. */ |
| + if (tdep->sc_reg_offset == NULL) |
| + return cache; |
| + |
| + /* Find the address of the sigcontext structure. */ |
| + CORE_ADDR addr = tdep->sigcontext_addr (this_frame); |
| + |
| + /* For each register, if its contents have been saved within the |
| + sigcontext structure, determine the address of those contents. */ |
| + gdb_assert (tdep->sc_num_regs <= (ARC_LAST_REGNUM + 1)); |
| + for (int i = 0; i < tdep->sc_num_regs; i++) |
| + { |
| + if (tdep->sc_reg_offset[i] != ARC_OFFSET_NO_REGISTER) |
| + cache->saved_regs[i].addr = addr + tdep->sc_reg_offset[i]; |
| + } |
| + |
| + return cache; |
| +} |
| + |
| +/* Implement the "this_id" frame_unwind method for signal trampoline |
| + frames. */ |
| + |
| +static void |
| +arc_sigtramp_frame_this_id (struct frame_info *this_frame, |
| + void **this_cache, struct frame_id *this_id) |
| +{ |
| + if (arc_debug) |
| + debug_printf ("arc: sigtramp_frame_this_id\n"); |
| + |
| + if (*this_cache == NULL) |
| + *this_cache = arc_make_sigtramp_frame_cache (this_frame); |
| + |
| + struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| + struct arc_frame_cache *cache = (struct arc_frame_cache *) *this_cache; |
| + CORE_ADDR stack_addr = cache->prev_sp; |
| + CORE_ADDR code_addr |
| + = get_frame_register_unsigned (this_frame, gdbarch_pc_regnum (gdbarch)); |
| + *this_id = frame_id_build (stack_addr, code_addr); |
| +} |
| + |
| +/* Get a register from a signal handler frame. */ |
| + |
| +static struct value * |
| +arc_sigtramp_frame_prev_register (struct frame_info *this_frame, |
| + void **this_cache, int regnum) |
| +{ |
| + if (arc_debug) |
| + debug_printf ("arc: sigtramp_frame_prev_register (regnum = %d)\n", regnum); |
| + |
| + /* Make sure we've initialized the cache. */ |
| + if (*this_cache == NULL) |
| + *this_cache = arc_make_sigtramp_frame_cache (this_frame); |
| + |
| + struct arc_frame_cache *cache = (struct arc_frame_cache *) *this_cache; |
| + return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); |
| +} |
| + |
| +/* Frame sniffer for signal handler frame. Only recognize a frame if we |
| + have a sigcontext_addr handler in the target dependency. */ |
| + |
| +static int |
| +arc_sigtramp_frame_sniffer (const struct frame_unwind *self, |
| + struct frame_info *this_frame, |
| + void **this_cache) |
| +{ |
| + struct gdbarch_tdep *tdep; |
| + |
| + if (arc_debug) |
| + debug_printf ("arc: sigtramp_frame_sniffer\n"); |
| + |
| + tdep = gdbarch_tdep (get_frame_arch (this_frame)); |
| + |
| + /* If we have a sigcontext_addr handler, then just return 1 (same as the |
| + "default_frame_sniffer ()"). */ |
| + return (tdep->sigcontext_addr != NULL && tdep->is_sigtramp != NULL |
| + && tdep->is_sigtramp (this_frame)); |
| +} |
| + |
| /* Structure defining the ARC ordinary frame unwind functions. Since we are |
| the fallback unwinder, we use the default frame sniffer, which always |
| accepts the frame. */ |
| @@ -1858,6 +1956,21 @@ static const struct frame_unwind arc_frame_unwind = { |
| NULL |
| }; |
| |
| +/* Structure defining the ARC signal frame unwind functions. Custom |
| + sniffer is used, because this frame must be accepted only in the right |
| + context. */ |
| + |
| +static const struct frame_unwind arc_sigtramp_frame_unwind = { |
| + SIGTRAMP_FRAME, |
| + default_frame_unwind_stop_reason, |
| + arc_sigtramp_frame_this_id, |
| + arc_sigtramp_frame_prev_register, |
| + NULL, |
| + arc_sigtramp_frame_sniffer, |
| + NULL, |
| + NULL |
| +}; |
| + |
| |
| static const struct frame_base arc_normal_base = { |
| &arc_frame_unwind, |
| @@ -2272,6 +2385,7 @@ arc_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| /* Frame unwinders and sniffers. */ |
| dwarf2_frame_set_init_reg (gdbarch, arc_dwarf2_frame_init_reg); |
| dwarf2_append_unwinders (gdbarch); |
| + frame_unwind_append_unwinder (gdbarch, &arc_sigtramp_frame_unwind); |
| frame_unwind_append_unwinder (gdbarch, &arc_frame_unwind); |
| frame_base_set_default (gdbarch, &arc_normal_base); |
| |
| @@ -2350,6 +2464,15 @@ arc_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file) |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| fprintf_unfiltered (file, "arc_dump_tdep: jb_pc = %i\n", tdep->jb_pc); |
| + |
| + fprintf_unfiltered (file, "arc_dump_tdep: is_sigtramp = <%s>\n", |
| + host_address_to_string (tdep->is_sigtramp)); |
| + fprintf_unfiltered (file, "arc_dump_tdep: sigcontext_addr = <%s>\n", |
| + host_address_to_string (tdep->sigcontext_addr)); |
| + fprintf_unfiltered (file, "arc_dump_tdep: sc_reg_offset = <%s>\n", |
| + host_address_to_string (tdep->sc_reg_offset)); |
| + fprintf_unfiltered (file, "arc_dump_tdep: sc_num_regs = %d\n", |
| + tdep->sc_num_regs); |
| } |
| |
| /* This command accepts single argument - address of instruction to |
| diff --git a/gdb/arc-tdep.h b/gdb/arc-tdep.h |
| index 50b14905134..70fc3d95c48 100644 |
| --- a/gdb/arc-tdep.h |
| +++ b/gdb/arc-tdep.h |
| @@ -124,6 +124,19 @@ struct gdbarch_tdep |
| |
| /* Whether target has hardware (aka zero-delay) loops. */ |
| bool has_hw_loops; |
| + |
| + /* Detect sigtramp. */ |
| + bool (*is_sigtramp) (struct frame_info *); |
| + |
| + /* Get address of sigcontext for sigtramp. */ |
| + CORE_ADDR (*sigcontext_addr) (struct frame_info *); |
| + |
| + /* Offset of registers in `struct sigcontext'. */ |
| + const int *sc_reg_offset; |
| + |
| + /* Number of registers in sc_reg_offsets. Most likely a ARC_LAST_REGNUM, |
| + but in theory it could be less, so it is kept separate. */ |
| + int sc_num_regs; |
| }; |
| |
| /* Utility functions used by other ARC-specific modules. */ |
| -- |
| 2.16.2 |
| |