[Crash-utility] [PATCH] Reapply "vmcoreinfo: read vmcoreinfo using 'vmcoreinfo_data' when unavailable in elf note"

Commit 7636c13 ("vmcoreinfo: read vmcoreinfo using 'vmcoreinfo_data' when unavailable in elf note") moved the vmcoreinfo reading to always read from memory instead of relying on diskdump/netdump's local handlers. This was later reverted to fix regression in X86_64 kslar images. Reintroduce the `vmcoreinfo_read_from_memory` as fallback to diskdump/netdump vmcores. This reverts commit 72e2776caf1ca41dffcc8aba11c55c636565725b. Cc: Aditya Gupta <adityag(a)linux.ibm.com&gt; Cc: Tao Liu <ltao(a)redhat.com&gt; Signed-off-by: Shivang Upadhyay <shivangu(a)linux.ibm.com&gt; --- defs.h | 1 + diskdump.c | 3 +++ kernel.c | 17 ++++++++++++----- netdump.c | 2 ++ 4 files changed, 18 insertions(+), 5 deletions(-) diff --git a/defs.h b/defs.h index ceed3a9..e5d38c2 100644 --- a/defs.h +++ b/defs.h @@ -6235,6 +6235,7 @@ void dump_kernel_table(int); void dump_bt_info(struct bt_info *, char *where); void dump_log(int); void parse_kernel_version(char *); +char *vmcoreinfo_read_from_memory(const char *); #define LOG_LEVEL(v) ((v) & 0x07) #define SHOW_LOG_LEVEL (0x1) diff --git a/diskdump.c b/diskdump.c index 0ff8782..c16e7b9 100644 --- a/diskdump.c +++ b/diskdump.c @@ -2434,6 +2434,9 @@ err: if (buf) free(buf); + if (value_string == NULL) + return vmcoreinfo_read_from_memory(key); + return value_string; } diff --git a/kernel.c b/kernel.c index bb148d0..ec287bb 100644 --- a/kernel.c +++ b/kernel.c @@ -100,7 +100,6 @@ static ulong dump_audit_skb_queue(ulong); static ulong __dump_audit(char *); static void dump_audit(void); static void dump_printk_safe_seq_buf(int); -static char *vmcoreinfo_read_string(const char *); static void check_vmcoreinfo(void); static int is_pvops_xen(void); static int get_linux_banner_from_vmlinux(char *, size_t); @@ -11960,8 +11959,8 @@ dump_printk_safe_seq_buf(int msg_flags) * Returns a string (that has to be freed by the caller) that contains the * value for key or NULL if the key has not been found. */ -static char * -vmcoreinfo_read_string(const char *key) +char * +vmcoreinfo_read_from_memory(const char *key) { char *buf, *value_string, *p1, *p2; size_t value_length; @@ -11971,6 +11970,14 @@ vmcoreinfo_read_string(const char *key) buf = value_string = NULL; + if (!(pc->flags & GDB_INIT)) { + /* + * GDB interface hasn't been initialised yet, so can't + * access vmcoreinfo_data + */ + return NULL; + } + switch (get_symbol_type("vmcoreinfo_data", NULL, NULL)) { case TYPE_CODE_PTR: @@ -12026,10 +12033,10 @@ check_vmcoreinfo(void) switch (get_symbol_type("vmcoreinfo_data", NULL, NULL)) { case TYPE_CODE_PTR: - pc->read_vmcoreinfo = vmcoreinfo_read_string; + pc->read_vmcoreinfo = vmcoreinfo_read_from_memory; break; case TYPE_CODE_ARRAY: - pc->read_vmcoreinfo = vmcoreinfo_read_string; + pc->read_vmcoreinfo = vmcoreinfo_read_from_memory; break; } } diff --git a/netdump.c b/netdump.c index ba1c6c4..fd0d545 100644 --- a/netdump.c +++ b/netdump.c @@ -2020,6 +2020,8 @@ vmcoreinfo_read_string(const char *key) } } + if (value == NULL) + return vmcoreinfo_read_from_memory(key); return value; } -- 2.52.0