xtensa: implement NPTL helpers
Commit Message
These changes allow debugging multithreaded NPTL xtensa applications.
2015-08-20 Max Filippov <jcmvbkbc@gmail.com>
gdb/
* xtensa-linux-nat.c (gdb_proc_service.h): New #include.
(ps_get_thread_area): New function.
* xtensa-linux-tdep.c (xtensa_linux_init_abi): Add call to
set_gdbarch_fetch_tls_load_module_address to enable TLS support.
* xtensa-tdep.c (xtensa_gdbarch_init): Call gdbarch_init_osabi
to register xtensa-specific hooks.
* xtensa-tdep.h (struct xtensa_elf_gregset_t): Add threadptr
member.
---
gdb/xtensa-linux-nat.c | 19 +++++++++++++++++++
gdb/xtensa-linux-tdep.c | 4 ++++
gdb/xtensa-tdep.c | 3 +++
gdb/xtensa-tdep.h | 3 ++-
4 files changed, 28 insertions(+), 1 deletion(-)
Comments
On 08/20/2015 08:18 AM, Max Filippov wrote:
> These changes allow debugging multithreaded NPTL xtensa applications.
>
> 2015-08-20 Max Filippov <jcmvbkbc@gmail.com>
> gdb/
> * xtensa-linux-nat.c (gdb_proc_service.h): New #include.
> (ps_get_thread_area): New function.
> * xtensa-linux-tdep.c (xtensa_linux_init_abi): Add call to
> set_gdbarch_fetch_tls_load_module_address to enable TLS support.
> * xtensa-tdep.c (xtensa_gdbarch_init): Call gdbarch_init_osabi
> to register xtensa-specific hooks.
> * xtensa-tdep.h (struct xtensa_elf_gregset_t): Add threadptr
> member.
LGTM. Looks like gdbserver's linux-xtensa-low.c is also missing
the ps_get_thread_area implementation.
Thanks,
Pedro Alves
@@ -37,6 +37,9 @@
#include "gregset.h"
#include "xtensa-tdep.h"
+/* Defines ps_err_e, struct ps_prochandle. */
+#include "gdb_proc_service.h"
+
/* Extended register set depends on hardware configs.
Keeping these definitions separately allows to introduce
hardware-specific overlays. */
@@ -280,6 +283,22 @@ xtensa_linux_store_inferior_registers (struct target_ops *ops,
store_xtregs (regcache, regnum);
}
+ps_err_e
+ps_get_thread_area (const struct ps_prochandle *ph,
+ lwpid_t lwpid, int idx, void **base)
+{
+ xtensa_elf_gregset_t regs;
+ if (ptrace (PTRACE_GETREGS, lwpid, NULL, ®s) != 0)
+ return PS_ERR;
+
+ /* IDX is the bias from the thread pointer to the beginning of the
+ thread descriptor. It has to be subtracted due to implementation
+ quirks in libthread_db. */
+ *base = (void *) ((char *)regs.threadptr - idx);
+
+ return PS_OK;
+}
+
void _initialize_xtensa_linux_nat (void);
void
@@ -106,6 +106,10 @@ xtensa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
xtensa_linux_gdb_signal_from_target);
set_gdbarch_gdb_signal_to_target (gdbarch,
xtensa_linux_gdb_signal_to_target);
+
+ /* Enable TLS support. */
+ set_gdbarch_fetch_tls_load_module_address (gdbarch,
+ svr4_fetch_objfile_link_map);
}
/* Provide a prototype to silence -Wmissing-prototypes. */
@@ -3273,6 +3273,9 @@ xtensa_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_ilp32_fetch_link_map_offsets);
+ /* Hook in the ABI-specific overrides, if they have been registered. */
+ gdbarch_init_osabi (info, gdbarch);
+
return gdbarch;
}
@@ -96,7 +96,8 @@ typedef struct
xtensa_elf_greg_t sar;
xtensa_elf_greg_t windowstart;
xtensa_elf_greg_t windowbase;
- xtensa_elf_greg_t reserved[8+48];
+ xtensa_elf_greg_t threadptr;
+ xtensa_elf_greg_t reserved[7+48];
xtensa_elf_greg_t ar[64];
} xtensa_elf_gregset_t;