[PATCH] powerpc/kdump: handle crashkernel memory reservation failure

Subsystems: linux for powerpc (32-bit and 64-bit), the rest

STALE2938d

4 messages, 4 authors, 2018-07-19 · open the first message on its own page

[PATCH] powerpc/kdump: handle crashkernel memory reservation failure

From: Hari Bathini <hbathini@linux.ibm.com>
Date: 2018-06-28 05:20:08

Memory reservation for crashkernel could fail if there are holes around
kdump kernel offset (128M). Fail gracefully in such cases and print an
error message.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
---
 arch/powerpc/kernel/machine_kexec.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index 936c7e2..6181442 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c

@@ -188,7 +188,12 @@ void __init reserve_crashkernel(void)
 			(unsigned long)(crashk_res.start >> 20),
 			(unsigned long)(memblock_phys_mem_size() >> 20));
 
-	memblock_reserve(crashk_res.start, crash_size);
+	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
+	    memblock_reserve(crashk_res.start, crash_size)) {
+		printk(KERN_ERR "Failed to reserve memory for crashkernel!\n");
+		crashk_res.start = crashk_res.end = 0;
+		return;
+	}
 }
 
 int overlaps_crashkernel(unsigned long start, unsigned long size)

Re: [PATCH] powerpc/kdump: handle crashkernel memory reservation failure

From: David Gibson <hidden>
Date: 2018-06-28 05:33:12

On Thu, 28 Jun 2018 10:49:56 +0530
Hari Bathini [off-list ref] wrote:

Memory reservation for crashkernel could fail if there are holes around
kdump kernel offset (128M). Fail gracefully in such cases and print an
error message.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>

Tested-by: David Gibson <redacted>

quoted hunk

---
 arch/powerpc/kernel/machine_kexec.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index 936c7e2..6181442 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c

@@ -188,7 +188,12 @@ void __init reserve_crashkernel(void)
 			(unsigned long)(crashk_res.start >> 20),
 			(unsigned long)(memblock_phys_mem_size() >> 20));
 
-	memblock_reserve(crashk_res.start, crash_size);
+	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
+	    memblock_reserve(crashk_res.start, crash_size)) {
+		printk(KERN_ERR "Failed to reserve memory for crashkernel!\n");
+		crashk_res.start = crashk_res.end = 0;
+		return;
+	}
 }
 
 int overlaps_crashkernel(unsigned long start, unsigned long size)


-- 
David Gibson [off-list ref]
Principal Software Engineer, Virtualization, Red Hat

Re: [PATCH] powerpc/kdump: handle crashkernel memory reservation failure

From: Dave Young <hidden>
Date: 2018-06-28 06:48:45

On 06/28/18 at 10:49am, Hari Bathini wrote:

quoted hunk

Memory reservation for crashkernel could fail if there are holes around
kdump kernel offset (128M). Fail gracefully in such cases and print an
error message.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
---
 arch/powerpc/kernel/machine_kexec.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index 936c7e2..6181442 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c

@@ -188,7 +188,12 @@ void __init reserve_crashkernel(void)
 			(unsigned long)(crashk_res.start >> 20),
 			(unsigned long)(memblock_phys_mem_size() >> 20));
 
-	memblock_reserve(crashk_res.start, crash_size);
+	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
+	    memblock_reserve(crashk_res.start, crash_size)) {
+		printk(KERN_ERR "Failed to reserve memory for crashkernel!\n");
+		crashk_res.start = crashk_res.end = 0;
+		return;
+	}
 }
 
 int overlaps_crashkernel(unsigned long start, unsigned long size)

It would be better to print a separate error message for !memblock_is_region_memory
But I think memblock_reserve is unlikly to fail so this patch is also
good.

Reviewed-by: Dave Young <redacted>

Thanks
Dave

Re: powerpc/kdump: handle crashkernel memory reservation failure

From: Michael Ellerman <hidden>
Date: 2018-07-19 06:07:38

On Thu, 2018-06-28 at 05:19:56 UTC, Hari Bathini wrote:

Memory reservation for crashkernel could fail if there are holes around
kdump kernel offset (128M). Fail gracefully in such cases and print an
error message.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: David Gibson <redacted>
Reviewed-by: Dave Young <redacted>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/8950329c4a64c6d3ca0bc34711a1af

cheers

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