From: Hari Bathini <hbathini@linux.ibm.com>
To: lkml <linux-kernel@vger.kernel.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Kexec-ml <kexec@lists.infradead.org>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>,
Dave Young <dyoung@redhat.com>,
Mahesh J Salgaonkar <mahesh@linux.ibm.com>,
Baoquan He <bhe@redhat.com>
Subject: [PATCH v2 2/3] vmcore: allow fadump to export vmcore even if is_kdump_kernel() is false
Date: Wed, 6 Sep 2023 00:06:03 +0530 [thread overview]
Message-ID: <20230905183604.568996-2-hbathini@linux.ibm.com> (raw)
In-Reply-To: <20230905183604.568996-1-hbathini@linux.ibm.com>
Currently, is_kdump_kernel() returns true when elfcorehdr_addr is set.
While elfcorehdr_addr is set for kexec based kernel dump mechanism,
alternate dump capturing methods like fadump [1] also set it to export
the vmcore. Since, is_kdump_kernel() is used to restrict resources in
crash dump capture kernel and such restrictions are not desirable for
fadump, allow is_kdump_kernel() to be defined differently for fadump
case. With that change, include is_fadump_active() check in functions
is_vmcore_usable() & vmcore_unusable() to be able to export vmcore for
fadump case too.
[1] https://docs.kernel.org/powerpc/firmware-assisted-dump.html
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
---
Changes in v2:
* is_fadump_active() check added to is_vmcore_usable() as suggested
by Baoquan.
include/linux/crash_dump.h | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index 0f3a656293b0..de8a9fabfb6f 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -50,6 +50,7 @@ void vmcore_cleanup(void);
#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
#endif
+#ifndef is_kdump_kernel
/*
* is_kdump_kernel() checks whether this kernel is booting after a panic of
* previous kernel or not. This is determined by checking if previous kernel
@@ -64,6 +65,19 @@ static inline bool is_kdump_kernel(void)
{
return elfcorehdr_addr != ELFCORE_ADDR_MAX;
}
+#endif
+
+#ifndef is_fadump_active
+/*
+ * If f/w assisted dump capturing mechanism (fadump), instead of kexec based
+ * dump capturing mechanism (kdump) is exporting the vmcore, then this function
+ * will be defined in arch specific code to return true, when appropriate.
+ */
+static inline bool is_fadump_active(void)
+{
+ return false;
+}
+#endif
/* is_vmcore_usable() checks if the kernel is booting after a panic and
* the vmcore region is usable.
@@ -75,7 +89,8 @@ static inline bool is_kdump_kernel(void)
static inline int is_vmcore_usable(void)
{
- return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
+ return (is_kdump_kernel() || is_fadump_active())
+ && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
}
/* vmcore_unusable() marks the vmcore as unusable,
@@ -84,7 +99,7 @@ static inline int is_vmcore_usable(void)
static inline void vmcore_unusable(void)
{
- if (is_kdump_kernel())
+ if (is_kdump_kernel() || is_fadump_active())
elfcorehdr_addr = ELFCORE_ADDR_ERR;
}
--
2.41.0
next prev parent reply other threads:[~2023-09-05 19:31 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-05 18:36 [PATCH v2 1/3] powerpc/fadump: make is_fadump_active() visible for exporting vmcore Hari Bathini
2023-09-05 18:36 ` Hari Bathini [this message]
2023-09-11 7:13 ` [PATCH v2 2/3] vmcore: allow fadump to export vmcore even if is_kdump_kernel() is false Michael Ellerman
2023-09-11 10:31 ` Baoquan He
2023-09-12 8:31 ` Hari Bathini
2023-09-05 18:36 ` [PATCH v2 3/3] powerpc/fadump: make is_kdump_kernel() return false when fadump is active Hari Bathini
2023-09-07 5:42 ` [PATCH v2 1/3] powerpc/fadump: make is_fadump_active() visible for exporting vmcore Baoquan He
2023-09-08 5:49 ` Hari Bathini
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