This change:
commit b775012e84
Author: Luis Machado <luisgpm@br.ibm.com>
Date: Fri Feb 24 15:10:59 2012 +0000
2012-02-24 Luis Machado <lgustavo@codesourcery.com>
* remote.c (remote_supports_cond_breakpoints): New forward
declaration.
[...]
changed the way breakpoints are inserted and removed such that
`insert_bp_location' can now be called with the breakpoint being handled
already in place, while previously the call was only ever made for
breakpoints that have not been put in place. This in turn caused an
issue for software breakpoints and targets for which a breakpoint's
`placed_address' may not be the same as the original requested address.
The issue is `insert_bp_location' overwrites the previously adjusted
value in `placed_address' with the original address, that is only
replaced back with the correct adjusted address later on when
`gdbarch_breakpoint_from_pc' is called. Meanwhile there's a window
where the value in `placed_address' does not correspond to data stored
in `shadow_contents', leading to incorrect instruction bytes being
supplied when `one_breakpoint_xfer_memory' is called to supply the
instruction overlaid by the breakpoint.
And this is exactly what happens on the MIPS target with software
breakpoints placed in microMIPS code. In this case not only
`placed_address' is not the original address because of the ISA bit, but
`mips_breakpoint_from_pc' has to read the original instruction to
determine which one of the two software breakpoint instruction encodings
to choose as well. The 16-bit encoding is used to replace 16-bit
instructions and similarly the 32-bit one is used with 32-bit
instructions, to satisfy branch delay slot size requirements.
The mismatch between `placed_address' and the address data in
`shadow_contents' has been obtained from leads to the wrong encoding
being used in some cases, which in the case of a 32-bit software
breakpoint instruction replacing a 16-bit instruction causes corruption
to the adjacent following instruction and leads the debug session astray
if execution reaches there e.g. with a jump.
To address this problem I made the change below, that adds a
`reqstd_address' field to `struct bp_target_info' and leaves
`placed_address' unchanged once it has been set. This ensures data in
`shadow_contents' is always consistent with `placed_address'.
This approach also has this good side effect that all the places that
examine the breakpoint's address see a consistent value, either
`reqstd_address' or `placed_address', as required. Currently some
places see either the original or the adjusted address in
`placed_address', depending on whether they have been called before
`gdbarch_remote_breakpoint_from_pc' or afterwards. This is in
particular true for subsequent calls to
`gdbarch_remote_breakpoint_from_pc' itself, e.g. from
`one_breakpoint_xfer_memory'. This is also important for places like
`find_single_step_breakpoint' where a breakpoint's address is compared
to the raw value of $pc.
* breakpoint.h (bp_target_info): Add `reqstd_address' member,
update comments.
* breakpoint.c (one_breakpoint_xfer_memory): Use `reqstd_address'
for the breakpoint's address. Don't preinitialize `placed_size'.
(insert_bp_location): Set `reqstd_address' rather than
`placed_address'.
(bp_target_info_copy_insertion_state): Also copy `placed_address'.
(bkpt_insert_location): Use `reqstd_address' for the breakpoint's
address.
(bkpt_remove_location): Likewise.
(deprecated_insert_raw_breakpoint): Likewise.
(deprecated_remove_raw_breakpoint): Likewise.
(find_single_step_breakpoint): Likewise.
* mem-break.c (default_memory_insert_breakpoint): Use
`reqstd_address' for the breakpoint's address. Don't set
`placed_address' or `placed_size' if breakpoint contents couldn't
have been determined.
* remote.c (remote_insert_breakpoint): Use `reqstd_address' for
the breakpoint's address.
(remote_insert_hw_breakpoint): Likewise. Don't set
`placed_address' or `placed_size' if breakpoint couldn't have been
set.
* aarch64-linux-nat.c (aarch64_linux_insert_hw_breakpoint): Use
`reqstd_address' for the breakpoint's address.
* arm-linux-nat.c (arm_linux_hw_breakpoint_initialize): Likewise.
* ia64-tdep.c (ia64_memory_insert_breakpoint): Likewise.
* m32r-tdep.c (m32r_memory_insert_breakpoint): Likewise.
* microblaze-linux-tdep.c
(microblaze_linux_memory_remove_breakpoint): Likewise.
* monitor.c (monitor_insert_breakpoint): Likewise.
* nto-procfs.c (procfs_insert_breakpoint): Likewise.
(procfs_insert_hw_breakpoint): Likewise.
* ppc-linux-nat.c (ppc_linux_insert_hw_breakpoint): Likewise.
* ppc-linux-tdep.c (ppc_linux_memory_remove_breakpoint): Likewise.
* remote-m32r-sdi.c (m32r_insert_breakpoint): Likewise.
* remote-mips.c (mips_insert_breakpoint): Likewise.
* x86-nat.c (x86_insert_hw_breakpoint): Likewise.
This commit adds a new global flag show_debug_regs to common-debug.h
to replace the flag debug_hw_points used by gdbserver and by the
Linux x86 and AArch64 ports, and to replace the flag maint_show_dr
used by the Linux MIPS port.
Note that some debug printing in the AArch64 port was enabled only if
debug_hw_points > 1 but no way to set debug_hw_points to values other
than 0 and 1 was provided; that code was effectively dead. This
commit enables all debug printing if show_debug_regs is nonzero, so
the AArch64 output will be more verbose than previously.
gdb/ChangeLog:
* common/common-debug.h (show_debug_regs): Declare.
* common/common-debug.c (show_debug_regs): Define.
* aarch64-linux-nat.c (debug_hw_points): Don't define. Replace
all uses with show_debug_regs. Replace all uses that considered
debug_hw_points as a multi-value integer with straight boolean
uses.
* x86-nat.c (debug_hw_points): Don't define. Replace all uses
with show_debug_regs.
* nat/x86-dregs.c (debug_hw_points): Don't declare. Replace
all uses with show_debug_regs.
* mips-linux-nat.c (maint_show_dr): Don't define. Replace all
uses with show_debug_regs.
gdb/gdbserver/ChangeLog:
* server.h (debug_hw_points): Don't declare.
* server.c (debug_hw_points): Don't define. Replace all uses
with show_debug_regs.
* linux-aarch64-low.c (debug_hw_points): Don't define. Replace
all uses with show_debug_regs.
Recent gdb code refactor changes LONGEST from a macro to a typedef,
thus the use of it in aarch64-linux-nat.c is no longer valid.
2014-08-21 Bin Cheng <bin.cheng@arm.com>
* aarch64-linux-nat.c (dr_changed_t): Change the type from
unsigned LONGEST to ULONGEST.
In order to provide 'collect_regset' support, the generic function
regcache_collect_regset is exploited. Since this requires writing
appropriate register maps, these can be used for supply_regset as
well.
A recent change to glibc removed asm/ptrace.h from user.h for
AArch64. This meant that cross-native builds of gdb using trunk
glibc broke because aarch64-linux-nat.c because user_hwdebug_state
couldn't be found.
Fixed by including asm/ptrace.h like other ports.
2014-05-22 Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>
* aarch64-linux-nat.c (asm/ptrace.h): Include.
* aarch64-linux-nat.c (aarch64_linux_set_debug_regs): Set
iov.iov_len with the real length in use.
gdb/gdbserver/
* linux-aarch64-low.c (aarch64_linux_set_debug_regs): Set
iov.iov_len with the real length in use.
Yufeng Zhang <yufeng.zhang@arm.com>
* aarch64-linux-nat.c (aarch64_init_debug_reg_state): Delete.
(aarch64_inferior_data, struct aarch64_inferior_data):
Delete.
(struct aarch64_process_info): New.
(aarch64_process_list): New global.
(aarch64_find_process_pid, aarch64_add_process)
(aarch64_process_info_get): New functions.
(aarch64_inferior_data_get): Delete.
(aarch64_process_info_get): New function.
(aarch64_forget_process): New function.
(aarch64_get_debug_reg_state): New parameter 'pid'. Reimplement.
(aarch64_linux_prepare_to_resume): Pass the lwp's pid to
aarch64_get_debug_reg_state.
(aarch64_notify_debug_reg_change): Use iterate_over_lwps
instead of linux_nat_iterate_watchpoint_lwps.
(aarch64_linux_new_fork): New function.
(aarch64_linux_child_post_startup_inferior): Use
aarch64_forget_process instead of aarch64_init_debug_reg_state.
(aarch64_handle_breakpoint, aarch64_linux_insert_hw_breakpoint)
(aarch64_linux_remove_hw_breakpoint)
(aarch64_handle_aligned_watchpoint)
(aarch64_handle_unaligned_watchpoint)
(aarch64_linux_insert_watchpoint)
(aarch64_linux_remove_watchpoint)
(aarch64_linux_stopped_data_address): Adjust to pass the current
process id to aarch64_debug_reg_state.
(_initialize_aarch64_linux_nat): Install aarch64_linux_new_fork as
linux_nat_new_fork hook, and aarch64_forget_process as
linux_nat_forget_process hook; remove the call to
register_inferior_data_with_cleanup.
2013-02-13 Marcus Shawcroft <marcus.shawcroft@arm.com>
* aarch64-linux-nat.c (debug_reg_change_callback)
(aarch64_linux_get_debug_reg_capacity): ARI fix: Replace %llx with
%s and phex().
