All of lore.kernel.org
 help / color / mirror / Atom feed
From: Douglas Anderson <dianders@chromium.org>
To: jason.wessel@windriver.com, daniel.thompson@linaro.org,
	gregkh@linuxfoundation.org
Cc: agross@kernel.org, kgdb-bugreport@lists.sourceforge.net,
	catalin.marinas@arm.com, linux-serial@vger.kernel.org,
	sumit.garg@linaro.org, corbet@lwn.net, mingo@redhat.com,
	will@kernel.org, hpa@zytor.com, tglx@linutronix.de,
	frowand.list@gmail.com, bp@alien8.de, bjorn.andersson@linaro.org,
	jslaby@suse.com, Douglas Anderson <dianders@chromium.org>,
	Alexios Zavras <alexios.zavras@intel.com>,
	Allison Randal <allison@lohutok.net>,
	Dave Martin <Dave.Martin@arm.com>,
	"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 v3 05/11] arm64: Add call_break_hook() to early_brk64() for early kgdb
Date: Tue, 28 Apr 2020 14:13:45 -0700	[thread overview]
Message-ID: <20200428141218.v3.5.I22067ad43e77ddfd4b64c2d49030628480f9e8d9@changeid> (raw)
In-Reply-To: <20200428211351.85055-1-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 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..08a736175d2d 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
 	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;
 }
 
-- 
2.26.2.303.gf8c07b1a785-goog


WARNING: multiple messages have this Message-ID
From: Douglas Anderson <dianders@chromium.org>
To: jason.wessel@windriver.com, daniel.thompson@linaro.org,
	gregkh@linuxfoundation.org
Cc: Mark Rutland <mark.rutland@arm.com>,
	kgdb-bugreport@lists.sourceforge.net, bjorn.andersson@linaro.org,
	hpa@zytor.com, frowand.list@gmail.com, corbet@lwn.net,
	will@kernel.org, jinho lim <jordan.lim@samsung.com>,
	agross@kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-serial@vger.kernel.org, catalin.marinas@arm.com,
	Dave Martin <Dave.Martin@arm.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	jslaby@suse.com, Alexios Zavras <alexios.zavras@intel.com>,
	bp@alien8.de, tglx@linutronix.de, mingo@redhat.com,
	Allison Randal <allison@lohutok.net>,
	sumit.garg@linaro.org, Douglas Anderson <dianders@chromium.org>,
	linux-kernel@vger.kernel.org, James Morse <james.morse@arm.com>,
	Masami Hiramatsu <mhiramat@kernel.org>
Subject: [PATCH v3 05/11] arm64: Add call_break_hook() to early_brk64() for early kgdb
Date: Tue, 28 Apr 2020 14:13:45 -0700	[thread overview]
Message-ID: <20200428141218.v3.5.I22067ad43e77ddfd4b64c2d49030628480f9e8d9@changeid> (raw)
In-Reply-To: <20200428211351.85055-1-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 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..08a736175d2d 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
 	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;
 }
 
-- 
2.26.2.303.gf8c07b1a785-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2020-04-28 21:14 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-28 21:13 [PATCH v3 00/11] kgdb: Support late serial drivers; enable early debug w/ boot consoles Douglas Anderson
2020-04-28 21:13 ` Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 01/11] kgdb: Disable WARN_CONSOLE_UNLOCKED for all kgdb Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 02/11] Revert "kgdboc: disable the console lock when in kgdb" Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 03/11] kgdboc: Use a platform device to handle tty drivers showing up late Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 04/11] kgdb: Delay "kgdbwait" to dbg_late_init() by default Douglas Anderson
2020-04-30 15:49   ` Daniel Thompson
2020-04-30 16:35     ` Doug Anderson
2020-05-04 14:43       ` [Kgdb-bugreport] " Daniel Thompson
2020-04-28 21:13 ` Douglas Anderson [this message]
2020-04-28 21:13   ` [PATCH v3 05/11] arm64: Add call_break_hook() to early_brk64() for early kgdb Douglas Anderson
2020-05-11 14:59   ` Will Deacon
2020-05-11 14:59     ` Will Deacon
2020-05-11 22:45     ` Doug Anderson
2020-05-11 22:45       ` Doug Anderson
2020-05-12  7:35       ` Will Deacon
2020-05-12  7:35         ` Will Deacon
2020-05-12 15:27         ` Doug Anderson
2020-05-12 15:27           ` Doug Anderson
2020-05-13  6:17           ` Will Deacon
2020-05-13  6:17             ` Will Deacon
2020-05-13 23:08             ` Doug Anderson
2020-05-13 23:08               ` Doug Anderson
2020-04-28 21:13 ` [PATCH v3 06/11] kgdb: Prevent infinite recursive entries to the debugger Douglas Anderson
2020-04-30 16:52   ` Daniel Thompson
2020-04-28 21:13 ` [PATCH v3 07/11] kgdboc: Add kgdboc_earlycon to support early kgdb using boot consoles Douglas Anderson
2020-05-04 14:13   ` Daniel Thompson
2020-04-28 21:13 ` [PATCH v3 08/11] Documentation: kgdboc: Document new kgdboc_earlycon parameter Douglas Anderson
2020-05-04 14:40   ` Daniel Thompson
2020-04-28 21:13 ` [PATCH v3 09/11] serial: qcom_geni_serial: Support kgdboc_earlycon Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 10/11] serial: 8250_early: " Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 11/11] serial: amba-pl011: " Douglas Anderson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200428141218.v3.5.I22067ad43e77ddfd4b64c2d49030628480f9e8d9@changeid \
    --to=dianders@chromium.org \
    --cc=Dave.Martin@arm.com \
    --cc=agross@kernel.org \
    --cc=alexios.zavras@intel.com \
    --cc=allison@lohutok.net \
    --cc=bjorn.andersson@linaro.org \
    --cc=bp@alien8.de \
    --cc=catalin.marinas@arm.com \
    --cc=corbet@lwn.net \
    --cc=daniel.thompson@linaro.org \
    --cc=ebiederm@xmission.com \
    --cc=frowand.list@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=hpa@zytor.com \
    --cc=james.morse@arm.com \
    --cc=jason.wessel@windriver.com \
    --cc=jordan.lim@samsung.com \
    --cc=jslaby@suse.com \
    --cc=kgdb-bugreport@lists.sourceforge.net \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mhiramat@kernel.org \
    --cc=mingo@redhat.com \
    --cc=sumit.garg@linaro.org \
    --cc=tglx@linutronix.de \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.