From: Douglas Anderson <dianders@chromium.org>
To: jason.wessel@windriver.com, daniel.thompson@linaro.org,
gregkh@linuxfoundation.org
Cc: corbet@lwn.net, frowand.list@gmail.com,
bjorn.andersson@linaro.org, linux-serial@vger.kernel.org,
mingo@redhat.com, hpa@zytor.com, jslaby@suse.com,
kgdb-bugreport@lists.sourceforge.net, sumit.garg@linaro.org,
will@kernel.org, tglx@linutronix.de, agross@kernel.org,
catalin.marinas@arm.com, bp@alien8.de,
Douglas Anderson <dianders@chromium.org>,
Alexios Zavras <alexios.zavras@intel.com>,
Allison Randal <allison@lohutok.net>,
Dave Martin <Dave.Martin@arm.com>,
Enrico Weigelt <info@metux.net>,
"Eric W. Biederman" <ebiederm@xmission.com>,
James Morse <james.morse@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
jinho lim <jordan.lim@samsung.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v4 05/12] arm64: Add call_break_hook() to early_brk64() for early kgdb
Date: Thu, 7 May 2020 13:08:43 -0700 [thread overview]
Message-ID: <20200507130644.v4.5.I22067ad43e77ddfd4b64c2d49030628480f9e8d9@changeid> (raw)
In-Reply-To: <20200507200850.60646-1-dianders@chromium.org>
In order to make early kgdb work properly we need early_brk64() to be
able to call into it. This is as easy as adding a call into
call_break_hook() just like we do later in the normal brk_handler().
Once we do this we can let kgdb know that it can break into the
debugger a little earlier (specifically when parsing early_param's).
NOTE: without this patch it turns out that arm64 can't do breakpoints
even at dbg_late_init(), so if we decide something about this patch is
wrong we might need to move dbg_late_init() a little later.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
---
Changes in v4:
- Add "if KGDB" to "select ARCH_HAS_EARLY_DEBUG" in Kconfig.
Changes in v3:
- Change boolean weak function to KConfig.
Changes in v2: None
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/debug-monitors.h | 2 ++
arch/arm64/kernel/debug-monitors.c | 2 +-
arch/arm64/kernel/traps.c | 3 +++
4 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 40fb05d96c60..3d78f581269c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -13,6 +13,7 @@ config ARM64
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
+ select ARCH_HAS_EARLY_DEBUG if KGDB
select ARCH_HAS_FAST_MULTIPLIER
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
index 7619f473155f..2d82a0314d29 100644
--- a/arch/arm64/include/asm/debug-monitors.h
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -97,6 +97,8 @@ void unregister_user_break_hook(struct break_hook *hook);
void register_kernel_break_hook(struct break_hook *hook);
void unregister_kernel_break_hook(struct break_hook *hook);
+int call_break_hook(struct pt_regs *regs, unsigned int esr);
+
u8 debug_monitors_arch(void);
enum dbg_active_el {
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 48222a4760c2..59c353dfc8e9 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -297,7 +297,7 @@ void unregister_kernel_break_hook(struct break_hook *hook)
unregister_debug_hook(&hook->node);
}
-static int call_break_hook(struct pt_regs *regs, unsigned int esr)
+int call_break_hook(struct pt_regs *regs, unsigned int esr)
{
struct break_hook *hook;
struct list_head *list;
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index cf402be5c573..a8173f0c1774 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -1044,6 +1044,9 @@ int __init early_brk64(unsigned long addr, unsigned int esr,
if ((comment & ~KASAN_BRK_MASK) == KASAN_BRK_IMM)
return kasan_handler(regs, esr) != DBG_HOOK_HANDLED;
#endif
+ if (call_break_hook(regs, esr) == DBG_HOOK_HANDLED)
+ return 0;
+
return bug_handler(regs, esr) != DBG_HOOK_HANDLED;
}
--
2.26.2.645.ge9eca65c58-goog
next prev parent reply other threads:[~2020-05-07 20:09 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 20:08 [PATCH v4 00/12] kgdb: Support late serial drivers; enable early debug w/ boot consoles Douglas Anderson
2020-05-07 20:08 ` [PATCH v4 01/12] kgdb: Disable WARN_CONSOLE_UNLOCKED for all kgdb Douglas Anderson
2020-05-07 20:08 ` [PATCH v4 02/12] Revert "kgdboc: disable the console lock when in kgdb" Douglas Anderson
2020-05-07 20:08 ` [PATCH v4 03/12] kgdboc: Use a platform device to handle tty drivers showing up late Douglas Anderson
2020-05-18 16:46 ` Daniel Thompson
2020-05-07 20:08 ` [PATCH v4 04/12] kgdb: Delay "kgdbwait" to dbg_late_init() by default Douglas Anderson
2020-05-15 16:18 ` Daniel Thompson
2020-05-07 20:08 ` Douglas Anderson [this message]
2020-05-13 23:12 ` [PATCH v4 05/12] arm64: Add call_break_hook() to early_brk64() for early kgdb Doug Anderson
2020-05-07 20:08 ` [PATCH v4 06/12] kgdb: Prevent infinite recursive entries to the debugger Douglas Anderson
2020-05-07 20:08 ` [PATCH v4 07/12] kgdboc: Remove useless #ifdef CONFIG_KGDB_SERIAL_CONSOLE in kgdboc Douglas Anderson
2020-05-11 16:02 ` Daniel Thompson
2020-05-07 20:08 ` [PATCH v4 08/12] kgdboc: Add kgdboc_earlycon to support early kgdb using boot consoles Douglas Anderson
2020-05-07 20:08 ` [PATCH v4 09/12] Documentation: kgdboc: Document new kgdboc_earlycon parameter Douglas Anderson
2020-05-07 20:08 ` [PATCH v4 10/12] serial: qcom_geni_serial: Support kgdboc_earlycon Douglas Anderson
2020-05-07 20:08 ` [PATCH v4 11/12] serial: 8250_early: " Douglas Anderson
2020-05-07 20:08 ` [PATCH v4 12/12] serial: amba-pl011: " Douglas Anderson
2020-05-14 16:21 ` [PATCH v4 00/12] kgdb: Support late serial drivers; enable early debug w/ boot consoles Daniel Thompson
2020-05-14 16:34 ` Doug Anderson
2020-05-14 16:36 ` Greg Kroah-Hartman
2020-05-19 10:37 ` Daniel Thompson
2020-05-19 10:36 ` Daniel Thompson
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