Re: [PATCH v4 13/13] arm64: debug: remove debug exception registration infrastructure
From: Will Deacon <will@kernel.org>
Date: 2025-06-27 17:07:27
On Fri, Jun 20, 2025 at 10:12:07PM +0100, Ada Couprie Diaz wrote:
Now that debug exceptions are handled individually and without the need for dynamic registration, remove the unused registration infrastructure. This removes the external caller for `debug_exception_enter()` and `debug_exception_exit()`. Make them static again and remove them from the header. Remove `early_brk64()` as it has been made redundant by (arm64: debug: split brk64 exception entry) and is not used anymore. Note : in `early_brk64()` `bug_brk_handler()` is called unconditionally as a fall-through, but now `call_break_hook()` only calls it if the immediate matches. This does not change the behaviour in early boot, as if `bug_brk_handler()` was called on a non-BUG immediate it would return DBG_HOOK_ERROR anyway, which `call_break_hook()` will do if no immediate matches. Signed-off-by: Ada Couprie Diaz <redacted> Tested-by: Luis Claudio R. Goncalves <redacted> --- arch/arm64/include/asm/debug-monitors.h | 2 - arch/arm64/include/asm/exception.h | 6 --- arch/arm64/include/asm/system_misc.h | 4 -- arch/arm64/kernel/debug-monitors.c | 3 -- arch/arm64/kernel/entry-common.c | 4 +- arch/arm64/kernel/traps.c | 26 +----------- arch/arm64/mm/fault.c | 53 ------------------------- 7 files changed, 3 insertions(+), 95 deletions(-)
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quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 654c8ea46ec6..d6c5268e6947 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c@@ -1101,29 +1101,5 @@ int ubsan_brk_handler(struct pt_regs *regs, unsigned long esr) } #endif -/* - * Initial handler for AArch64 BRK exceptions - * This handler only used until debug_traps_init(). - */ -int __init early_brk64(unsigned long addr, unsigned long esr, - struct pt_regs *regs) -{ -#ifdef CONFIG_CFI_CLANG - if (esr_is_cfi_brk(esr)) - return cfi_brk_handler(regs, esr) != DBG_HOOK_HANDLED; -#endif -#ifdef CONFIG_KASAN_SW_TAGS - if ((esr_brk_comment(esr) & ~KASAN_BRK_MASK) == KASAN_BRK_IMM) - return kasan_brk_handler(regs, esr) != DBG_HOOK_HANDLED; -#endif -#ifdef CONFIG_UBSAN_TRAP - if (esr_is_ubsan_brk(esr)) - return ubsan_brk_handler(regs, esr) != DBG_HOOK_HANDLED; -#endif - return bug_brk_handler(regs, esr) != DBG_HOOK_HANDLED; -} - void __init trap_init(void) -{ - debug_traps_init(); -} +{}
nit: I think you can actually just remove trap_init() entirely as there's a weak definition in init/main.c With that: Reviewed-by: Will Deacon <will@kernel.org> Will