• Will Deacon's avatar
    ARM: 6356/1: hw-breakpoint: add ARM backend for the hw-breakpoint framework · f81ef4a9
    Will Deacon authored
    The hw-breakpoint framework in the kernel requires architecture-specific
    support in order to install, remove, validate and manage hardware
    breakpoints.
    
    This patch adds initial support for this framework to the ARM architecture,
    but restricts the number of watchpoints to a single resource to get around
    the fact that the Data Fault Address Register is unknown when a watchpoint
    debug exception is taken.
    
    On cores with v7 debug, the Kernel can handle breakpoint and watchpoint
    exceptions occuring from userspace. Older cores require clients to handle
    the exception themselves by registering an appropriate overflow handler
    or, in the case of ptrace, handling the raised SIGTRAP.
    
    The memory-mapped extended debug interface is unsupported due to its
    unreliability in real implementations.
    
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: S. Karthikeyan <informkarthik@gmail.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
    f81ef4a9
hw_breakpoint.h 3.12 KB