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 1/2] vmcore: allow alternate dump capturing methods to export vmcore without is_kdump_kernel()
Date: Sat, 2 Sep 2023 00:34:37 +0530 [thread overview]
Message-ID: <20230901190438.375678-1-hbathini@linux.ibm.com> (raw)
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. is_kdump_kernel() is used to restrict resources in crash
dump capture kernel but such restrictions may not be desirable for
fadump. Allow is_kdump_kernel() to be defined differently for such
scenarios. With this, is_kdump_kernel() could be false while vmcore
is usable. So, introduce is_crashdump_kernel() to return true when
elfcorehdr_addr is set and use it for vmcore related checks.
[1] https://docs.kernel.org/powerpc/firmware-assisted-dump.html
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
---
include/linux/crash_dump.h | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index 0f3a656293b0..1052a0faf0dd 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
+
+/*
+ * Return true if this is a dump capture kernel, where vmcore needs to be
+ * exported, irrespective of the dump capture mechanism in use.
+ *
+ * Same as is_kdump_kernel() unless arch specific code defines is_kdump_kernel()
+ * differently while supporting other dump capturing mechanisms.
+ */
+static inline bool is_crashdump_kernel(void)
+{
+ return elfcorehdr_addr != ELFCORE_ADDR_MAX;
+}
/* is_vmcore_usable() checks if the kernel is booting after a panic and
* the vmcore region is usable.
@@ -75,7 +89,7 @@ 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_crashdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
}
/* vmcore_unusable() marks the vmcore as unusable,
@@ -84,7 +98,7 @@ static inline int is_vmcore_usable(void)
static inline void vmcore_unusable(void)
{
- if (is_kdump_kernel())
+ if (is_crashdump_kernel())
elfcorehdr_addr = ELFCORE_ADDR_ERR;
}
--
2.41.0
next reply other threads:[~2023-09-01 19:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-01 19:04 Hari Bathini [this message]
2023-09-01 19:04 ` [PATCH 2/2] powerpc/fadump: make is_kdump_kernel() return false when fadump is active Hari Bathini
2023-09-03 3:36 ` [PATCH 1/2] vmcore: allow alternate dump capturing methods to export vmcore without is_kdump_kernel() Baoquan He
2023-09-04 14:34 ` Hari Bathini
2023-09-05 2:30 ` Baoquan He
2023-09-05 19:25 ` Hari Bathini
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