From 3437254d7b5bc57d3a298df8640ae2f55bdbff2a Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Fri, 10 Oct 2014 15:57:13 +0100 Subject: [PATCH] Split vDSO range lookup to a gdbarch hook We have a case in solib-svr4.c where we could reuse symfile-mem.c's vDSO range lookup. Since symfile-mem.c is not present in all configurations solib-svr4.c is, move that lookup to a gdbarch hook. This has the minor (good) side effect that we stop even trying the target_auxv_search lookup against targets that don't have a concept of a vDSO, in case symfile-mem.c happens to be linked in the build (--enable-targets=all). Tested on x86_64 Fedora 20. gdb/ 2014-10-10 Pedro Alves * arch-utils.c (default_vsyscall_range): New function. * arch-utils.h (default_vsyscall_range): New declaration. * gdbarch.sh (vsyscall_range): New hook. * gdbarch.h, gdbarch.c: Regenerate. * linux-tdep.c (linux_vsyscall_range): New function. (linux_init_abi): Install linux_vsyscall_range as vsyscall_range gdbarch hook. * memrange.c (address_in_mem_range): New function. * memrange.h (address_in_mem_range): New declaration. * symfile-mem.c (find_vdso_size): Delete function. (add_vsyscall_page): Use gdbarch_vsyscall_range. --- gdb/ChangeLog | 14 ++++++++++++++ gdb/arch-utils.c | 8 ++++++++ gdb/arch-utils.h | 4 ++++ gdb/gdbarch.c | 23 +++++++++++++++++++++++ gdb/gdbarch.h | 10 ++++++++++ gdb/gdbarch.sh | 7 +++++++ gdb/linux-tdep.c | 35 +++++++++++++++++++++++++++++++++++ gdb/memrange.c | 9 +++++++++ gdb/memrange.h | 5 +++++ gdb/symfile-mem.c | 31 +++++-------------------------- 10 files changed, 120 insertions(+), 26 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 8d5b1ee97c5..89236986d76 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,17 @@ +2014-10-10 Pedro Alves + + * arch-utils.c (default_vsyscall_range): New function. + * arch-utils.h (default_vsyscall_range): New declaration. + * gdbarch.sh (vsyscall_range): New hook. + * gdbarch.h, gdbarch.c: Regenerate. + * linux-tdep.c (linux_vsyscall_range): New function. + (linux_init_abi): Install linux_vsyscall_range as + vsyscall_range gdbarch hook. + * memrange.c (address_in_mem_range): New function. + * memrange.h (address_in_mem_range): New declaration. + * symfile-mem.c (find_vdso_size): Delete function. + (add_vsyscall_page): Use gdbarch_vsyscall_range. + 2014-10-10 Pedro Alves * infrun.c (normal_stop): Fix typo in comment. diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c index 5ae9fb35588..41cf8280f8e 100644 --- a/gdb/arch-utils.c +++ b/gdb/arch-utils.c @@ -243,6 +243,14 @@ default_remote_register_number (struct gdbarch *gdbarch, return regno; } +/* See arch-utils.h. */ + +int +default_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range) +{ + return 0; +} + /* Functions to manipulate the endianness of the target. */ diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h index 46d157302b5..a60966288a9 100644 --- a/gdb/arch-utils.h +++ b/gdb/arch-utils.h @@ -174,4 +174,8 @@ extern int default_return_in_first_hidden_param_p (struct gdbarch *, extern int default_insn_is_call (struct gdbarch *, CORE_ADDR); extern int default_insn_is_ret (struct gdbarch *, CORE_ADDR); extern int default_insn_is_jump (struct gdbarch *, CORE_ADDR); + +/* Do-nothing version of vsyscall_range. Returns false. */ + +extern int default_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range); #endif diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c index e96d651970f..298435804b5 100644 --- a/gdb/gdbarch.c +++ b/gdb/gdbarch.c @@ -315,6 +315,7 @@ struct gdbarch gdbarch_insn_is_ret_ftype *insn_is_ret; gdbarch_insn_is_jump_ftype *insn_is_jump; gdbarch_auxv_parse_ftype *auxv_parse; + gdbarch_vsyscall_range_ftype *vsyscall_range; }; /* Create a new ``struct gdbarch'' based on information provided by @@ -407,6 +408,7 @@ gdbarch_alloc (const struct gdbarch_info *info, gdbarch->insn_is_call = default_insn_is_call; gdbarch->insn_is_ret = default_insn_is_ret; gdbarch->insn_is_jump = default_insn_is_jump; + gdbarch->vsyscall_range = default_vsyscall_range; /* gdbarch_alloc() */ return gdbarch; @@ -626,6 +628,7 @@ verify_gdbarch (struct gdbarch *gdbarch) /* Skip verify of insn_is_ret, invalid_p == 0 */ /* Skip verify of insn_is_jump, invalid_p == 0 */ /* Skip verify of auxv_parse, has predicate. */ + /* Skip verify of vsyscall_range, invalid_p == 0 */ buf = ui_file_xstrdup (log, &length); make_cleanup (xfree, buf); if (length > 0) @@ -1291,6 +1294,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file) fprintf_unfiltered (file, "gdbarch_dump: virtual_frame_pointer = <%s>\n", host_address_to_string (gdbarch->virtual_frame_pointer)); + fprintf_unfiltered (file, + "gdbarch_dump: vsyscall_range = <%s>\n", + host_address_to_string (gdbarch->vsyscall_range)); fprintf_unfiltered (file, "gdbarch_dump: vtable_function_descriptors = %s\n", plongest (gdbarch->vtable_function_descriptors)); @@ -4383,6 +4389,23 @@ set_gdbarch_auxv_parse (struct gdbarch *gdbarch, gdbarch->auxv_parse = auxv_parse; } +int +gdbarch_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range) +{ + gdb_assert (gdbarch != NULL); + gdb_assert (gdbarch->vsyscall_range != NULL); + if (gdbarch_debug >= 2) + fprintf_unfiltered (gdb_stdlog, "gdbarch_vsyscall_range called\n"); + return gdbarch->vsyscall_range (gdbarch, range); +} + +void +set_gdbarch_vsyscall_range (struct gdbarch *gdbarch, + gdbarch_vsyscall_range_ftype vsyscall_range) +{ + gdbarch->vsyscall_range = vsyscall_range; +} + /* Keep a registry of per-architecture data-pointers required by GDB modules. */ diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h index 6e840040331..f5330c21c85 100644 --- a/gdb/gdbarch.h +++ b/gdb/gdbarch.h @@ -59,6 +59,7 @@ struct axs_value; struct stap_parse_info; struct ravenscar_arch_ops; struct elf_internal_linux_prpsinfo; +struct mem_range; /* The architecture associated with the inferior through the connection to the target. @@ -1320,6 +1321,15 @@ typedef int (gdbarch_auxv_parse_ftype) (struct gdbarch *gdbarch, gdb_byte **read extern int gdbarch_auxv_parse (struct gdbarch *gdbarch, gdb_byte **readptr, gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp); extern void set_gdbarch_auxv_parse (struct gdbarch *gdbarch, gdbarch_auxv_parse_ftype *auxv_parse); +/* Find the address range of the current inferior's vsyscall/vDSO, and + write it to *RANGE. If the vsyscall's length can't be determined, a + range with zero length is returned. Returns true if the vsyscall is + found, false otherwise. */ + +typedef int (gdbarch_vsyscall_range_ftype) (struct gdbarch *gdbarch, struct mem_range *range); +extern int gdbarch_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range); +extern void set_gdbarch_vsyscall_range (struct gdbarch *gdbarch, gdbarch_vsyscall_range_ftype *vsyscall_range); + /* Definition for an unknown syscall, used basically in error-cases. */ #define UNKNOWN_SYSCALL (-1) diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh index c7858875cba..5442799b8cb 100755 --- a/gdb/gdbarch.sh +++ b/gdb/gdbarch.sh @@ -1030,6 +1030,12 @@ m:int:insn_is_jump:CORE_ADDR addr:addr::default_insn_is_jump::0 # Return -1 if there is insufficient buffer for a whole entry. # Return 1 if an entry was read into *TYPEP and *VALP. M:int:auxv_parse:gdb_byte **readptr, gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp:readptr, endptr, typep, valp + +# Find the address range of the current inferior's vsyscall/vDSO, and +# write it to *RANGE. If the vsyscall's length can't be determined, a +# range with zero length is returned. Returns true if the vsyscall is +# found, false otherwise. +m:int:vsyscall_range:struct mem_range *range:range::default_vsyscall_range::0 EOF } @@ -1149,6 +1155,7 @@ struct axs_value; struct stap_parse_info; struct ravenscar_arch_ops; struct elf_internal_linux_prpsinfo; +struct mem_range; /* The architecture associated with the inferior through the connection to the target. diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c index 7a766707994..2ffd992f9f4 100644 --- a/gdb/linux-tdep.c +++ b/gdb/linux-tdep.c @@ -1796,6 +1796,40 @@ linux_gdb_signal_to_target (struct gdbarch *gdbarch, return -1; } +/* Rummage through mappings to find a mapping's size. */ + +static int +find_mapping_size (CORE_ADDR vaddr, unsigned long size, + int read, int write, int exec, int modified, + void *data) +{ + struct mem_range *range = data; + + if (vaddr == range->start) + { + range->length = size; + return 1; + } + return 0; +} + +/* Implementation of the "vsyscall_range" gdbarch hook. */ + +static int +linux_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range) +{ + if (target_auxv_search (¤t_target, AT_SYSINFO_EHDR, &range->start) <= 0) + return 0; + + /* This is installed by linux_init_abi below, so should always be + available. */ + gdb_assert (gdbarch_find_memory_regions_p (target_gdbarch ())); + + range->length = 0; + gdbarch_find_memory_regions (gdbarch, find_mapping_size, range); + return 1; +} + /* To be called from the various GDB_OSABI_LINUX handlers for the various GNU/Linux architectures and machine types. */ @@ -1813,6 +1847,7 @@ linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) linux_gdb_signal_from_target); set_gdbarch_gdb_signal_to_target (gdbarch, linux_gdb_signal_to_target); + set_gdbarch_vsyscall_range (gdbarch, linux_vsyscall_range); } /* Provide a prototype to silence -Wmissing-prototypes. */ diff --git a/gdb/memrange.c b/gdb/memrange.c index 2895ff2df1f..485550b29b0 100644 --- a/gdb/memrange.c +++ b/gdb/memrange.c @@ -31,6 +31,15 @@ mem_ranges_overlap (CORE_ADDR start1, int len1, return (l < h); } +/* See memrange.h. */ + +int +address_in_mem_range (CORE_ADDR address, const struct mem_range *r) +{ + return (r->start <= address + && (address - r->start) < r->length); +} + /* qsort comparison function, that compares mem_ranges. Ranges are sorted in ascending START order. */ diff --git a/gdb/memrange.h b/gdb/memrange.h index 8c25d0adae3..2591789ad33 100644 --- a/gdb/memrange.h +++ b/gdb/memrange.h @@ -43,6 +43,11 @@ DEF_VEC_O(mem_range_s); extern int mem_ranges_overlap (CORE_ADDR start1, int len1, CORE_ADDR start2, int len2); +/* Returns true if ADDR is in RANGE. */ + +extern int address_in_mem_range (CORE_ADDR addr, + const struct mem_range *range); + /* Sort ranges by start address, then coalesce contiguous or overlapping ranges. */ diff --git a/gdb/symfile-mem.c b/gdb/symfile-mem.c index b6986b0ec72..eea97fd88b4 100644 --- a/gdb/symfile-mem.c +++ b/gdb/symfile-mem.c @@ -187,33 +187,15 @@ symbol_file_add_from_memory_wrapper (struct ui_out *uiout, void *data) return 0; } -/* Rummage through mappings to find the vsyscall page size. */ - -static int -find_vdso_size (CORE_ADDR vaddr, unsigned long size, - int read, int write, int exec, int modified, - void *data) -{ - struct symbol_file_add_from_memory_args *args = data; - - if (vaddr == args->sysinfo_ehdr) - { - args->size = size; - return 1; - } - return 0; -} - /* Try to add the symbols for the vsyscall page, if there is one. This function is called via the inferior_created observer. */ static void add_vsyscall_page (struct target_ops *target, int from_tty) { - CORE_ADDR sysinfo_ehdr; + struct mem_range vsyscall_range; - if (target_auxv_search (target, AT_SYSINFO_EHDR, &sysinfo_ehdr) > 0 - && sysinfo_ehdr != (CORE_ADDR) 0) + if (gdbarch_vsyscall_range (target_gdbarch (), &vsyscall_range)) { struct bfd *bfd; struct symbol_file_add_from_memory_args args; @@ -236,14 +218,11 @@ add_vsyscall_page (struct target_ops *target, int from_tty) return; } args.bfd = bfd; - args.sysinfo_ehdr = sysinfo_ehdr; - args.size = 0; - if (gdbarch_find_memory_regions_p (target_gdbarch ())) - (void) gdbarch_find_memory_regions (target_gdbarch (), - find_vdso_size, &args); + args.sysinfo_ehdr = vsyscall_range.start; + args.size = vsyscall_range.length; args.name = xstrprintf ("system-supplied DSO at %s", - paddress (target_gdbarch (), sysinfo_ehdr)); + paddress (target_gdbarch (), vsyscall_range.start)); /* Pass zero for FROM_TTY, because the action of loading the vsyscall DSO was not triggered by the user, even if the user typed "run" at the TTY. */ -- 2.30.2