arch_uprobe_pre_xol needs to emulate a branch if a branch instruction
has been replaced with a breakpoint, but in fact an uninitialised local
variable was passed to the emulator routine instead of the original
instruction
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 40e084a506 ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14300/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Generic kernel code implements a weak version of set_orig_insn that
moves cached 'insn' from arch_uprobe to the original code location when
the trap is removed.
MIPS variant used arch_uprobe->orig_inst which was never initialised
properly, so this code only inserted a nop instead of the original
instruction. With that change orig_inst can also be safely removed.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 40e084a506 ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14299/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
arch_uretprobe_hijack_return_addr should replace the return address for
a call with a trampoline address.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 40e084a506 ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14298/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When a uprobe-replacement breakpoint instruction is handled, a notifier
is called with DIE_UPROBE argument, but a corresponding exception notify
handler for MIPS attempts to handle DIE_BREAK instead. As a result
the breakpoint instruction isn't handled by the uprobe code and the probed
application terminates with SIGTRAP.
Fix this by changing arch_uprobe_exception_notify code to handle
DIE_UPROBE as a pre-singlestep condition instead of DIE_BREAK.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13884/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
