Thread (10 messages) flat view 10 messages, 2 authors, 2026-02-28

Re: [PATCH v7 3/5] crash: Use crash_exclude_core_ranges() on powerpc

From: Sourabh Jain <hidden>
Date: 2026-02-27 14:51:58
Also in: kexec, linux-devicetree, linux-doc, linux-riscv, lkml, loongarch
Subsystem: linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Linus Torvalds

Resend of: 
https://lore.kernel.org/all/19cf18b5-362d-4ff2-8b85-e2e72809250c@linux.ibm.com/ (local)

On 26/02/26 18:34, Jinjie Ruan wrote:
quoted hunk ↗ jump to hunk
The crash memory exclude of crashk_res and crashk_cma memory on powerpc
are almost identical to the generic crash_exclude_core_ranges().

By introducing the architecture-specific arch_crash_exclude_mem_range()
function with a default implementation of crash_exclude_mem_range(),
and using crash_exclude_mem_range_guarded as powerpc's separate
implementation, the generic crash_exclude_core_ranges() helper function
can be reused.

Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <redacted>
---
  arch/powerpc/kexec/ranges.c | 16 ++++------------
  include/linux/crash_core.h  |  4 ++++
  kernel/crash_core.c         | 19 +++++++++++++------
  3 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
index 6c58bcc3e130..e5fea23b191b 100644
--- a/arch/powerpc/kexec/ranges.c
+++ b/arch/powerpc/kexec/ranges.c
@@ -553,9 +553,9 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges)
  #endif /* CONFIG_KEXEC_FILE */
  
  #ifdef CONFIG_CRASH_DUMP
-int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
-					   unsigned long long mstart,
-					   unsigned long long mend)
+int arch_crash_exclude_mem_range(struct crash_mem **mem_ranges,
+				 unsigned long long mstart,
+				 unsigned long long mend)

update_crash_elfcorehdr() in arch/powerpc/kexec/crash.c still calls
crash_exclude_mem_range_guarded(), causing a build failure.

ld: arch/powerpc/kexec/crash.o: in function `update_crash_elfcorehdr':
/root/linux/arch/powerpc/kexec/crash.c:454: undefined reference to 
`crash_exclude_mem_range_guarded'


To fix this:
--------------
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index 898742a5205c..e59e909c369d 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -451,7 +451,7 @@ static void update_crash_elfcorehdr(struct kimage 
*image, struct memory_notify *
                 base_addr = PFN_PHYS(mn->start_pfn);
                 size = mn->nr_pages * PAGE_SIZE;
                 end = base_addr + size - 1;
-               ret = crash_exclude_mem_range_guarded(&cmem, base_addr, 
end);
+              ret = arch_crash_exclude_mem_range(&cmem, base_addr, end);
                 if (ret) {
                         pr_err("Failed to remove hot-unplugged memory 
from crash memory ranges\n");
                         goto out;

With the above change included, things are working fine on powerpc.

quoted hunk ↗ jump to hunk
  {
  	struct crash_mem *tmem = *mem_ranges;
  
@@ -604,18 +604,10 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges)
  			sort_memory_ranges(*mem_ranges, true);
  	}
  
-	/* Exclude crashkernel region */
-	ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end);
+	ret = crash_exclude_core_ranges(mem_ranges);
  	if (ret)
  		goto out;
  
-	for (i = 0; i < crashk_cma_cnt; ++i) {
-		ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start,
-					      crashk_cma_ranges[i].end);
-		if (ret)
-			goto out;
-	}
-
  	/*
  	 * FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
  	 *        regions are exported to save their context at the time of
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index 033b20204aca..dbec826dc53b 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -68,6 +68,7 @@ extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_ma
  				       void **addr, unsigned long *sz);
  extern int crash_prepare_headers(int need_kernel_map, void **addr,
  				 unsigned long *sz, unsigned long *nr_mem_ranges);
+extern int crash_exclude_core_ranges(struct crash_mem **cmem);
  
  struct kimage;
  struct kexec_segment;
@@ -88,6 +89,9 @@ extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
  extern unsigned int arch_get_system_nr_ranges(void);
  extern int arch_crash_populate_cmem(struct crash_mem *cmem);
  extern int arch_crash_exclude_ranges(struct crash_mem *cmem);
+extern int arch_crash_exclude_mem_range(struct crash_mem **mem,
+					unsigned long long mstart,
+					unsigned long long mend);
  
  #else /* !CONFIG_CRASH_DUMP*/
  struct pt_regs;
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 96a96e511f5a..300d44ad5471 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -287,24 +287,31 @@ unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }
  int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }
  int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }
  
-static int crash_exclude_core_ranges(struct crash_mem *cmem)
+int __weak arch_crash_exclude_mem_range(struct crash_mem **mem,
+					unsigned long long mstart,
+					unsigned long long mend)
+{
+	return crash_exclude_mem_range(*mem, mstart, mend);
+}
+
+int crash_exclude_core_ranges(struct crash_mem **cmem)
  {
  	int ret, i;
  
  	/* Exclude crashkernel region */
-	ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
+	ret = arch_crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
  	if (ret)
  		return ret;
  
  	if (crashk_low_res.end) {
-		ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+		ret = arch_crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
  		if (ret)
  			return ret;
  	}
  
  	for (i = 0; i < crashk_cma_cnt; ++i) {
-		ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
-					      crashk_cma_ranges[i].end);
+		ret = arch_crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
+						   crashk_cma_ranges[i].end);
  		if (ret)
  			return ret;
  	}
@@ -331,7 +338,7 @@ int crash_prepare_headers(int need_kernel_map, void **addr, unsigned long *sz,
  	if (ret)
  		goto out;
  
-	ret = crash_exclude_core_ranges(cmem);
+	ret = crash_exclude_core_ranges(&cmem);
  	if (ret)
  		goto out;
  
  
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