[PATCH v2 2/6] crash: Notify pre-kdump callbacks before switching kernels

[Zack Rusin <zack.rusin@broadcom.com>]

Fatal x86 oopses can call crash_kexec() without reaching panic(). Run the
pre-kdump chain from __crash_kexec() as well, after finding a loaded image
under the kexec lock and capturing the original registers.

This covers direct crash entry without moving all panic notifiers ahead
of kdump. A missing image or failed trylock leaves callbacks uncalled;
the shared guard skips callbacks already invoked by panic().

Link: https://lore.kernel.org/r/aquttpMVKX8e6zGB@pathway.suse.cz
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
---
New in v2: cover direct crash-kexec entry in a separate core patch.

 kernel/crash_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 2b36aa9fade0..5d9fe9e00f39 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -23,6 +23,7 @@
 #include <linux/objtool.h>
 #include <linux/delay.h>
 #include <linux/panic.h>
+#include <linux/panic_notifier.h>
 
 #include <asm/page.h>
 #include <asm/sections.h>
@@ -139,6 +140,7 @@ void __noclone __crash_kexec(struct pt_regs *regs)
 			struct pt_regs fixed_regs;
 
 			crash_setup_regs(&fixed_regs, regs);
+			panic_notify_pre_kdump(NULL);
 			crash_save_vmcoreinfo();
 			machine_crash_shutdown(&fixed_regs);
 			crash_cma_clear_pending_dma();