[Patch v2] get MODULES_VADDR by KERNEL_IMAGE_SIZE for x86_64

[Atsushi Kumagai]

>On 09/24/14 at 07:55am, Atsushi Kumagai wrote:
>> >diff --git a/makedumpfile.c b/makedumpfile.c
>> >index b4d43d8..65c893f 100644
>> >--- a/makedumpfile.c
>> >+++ b/makedumpfile.c
>> >@@ -1564,6 +1564,14 @@ get_value_for_old_linux(void)
>> > 			NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE) =
>> > 			PAGE_BUDDY_MAPCOUNT_VALUE_v2_6_39_to_latest_version;
>> > 	}
>> >+#ifdef __x86_64__
>> >+	if (NUMBER(KERNEL_IMAGE_SIZE) == NOT_FOUND_NUMBER) {
>> >+		if (info->kernel_version < KERNEL_VERSION(2, 6, 26))
>> >+			NUMBER(KERNEL_IMAGE_SIZE) = KERNEL_IMAGE_SIZE_ORIG;
>> >+		else
>> >+			NUMBER(KERNEL_IMAGE_SIZE) = KERNEL_IMAGE_SIZE_2_6_26;
>> >+	}
>> >+#endif

I noticed that this fix is incomplete because get_value_for_old_linux() is
too late as shown below:

  initial()
    + read_vmcoreinfo_from_vmcore()       // get KERNEL_IMAGE_SIZE from VMCOREINFO (only for new kernels)
    + get_mem_map()                       // refer KERNEL_IMAGE_SIZE via is_vmalloc_addr_x86_64()
    + get_value_for_old_linux()           // initialize KERNEL_IMAGE_SIZE for old kernels


So I'll fix this issue with the patch below.

Thanks,
Atsushi Kumagai


From: Atsushi Kumagai <kumagai-atsushi at mxc.nes.nec.co.jp>
Date: Mon, 20 Oct 2014 16:04:57 +0900
Subject: [PATCH] Initialize symbols early for old kernels.

It's best to invoke get_value_for_old_linux() immediately after
reading VMCOREINFO since some functions require the symbols which
are initialized in it.
This change is safe because get_value_for_old_linux() doesn't
overwrite any values.

Signed-off-by: Atsushi Kumagai <kumagai-atsushi at mxc.nes.nec.co.jp>
---
 makedumpfile.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/makedumpfile.c b/makedumpfile.c
index 53c3585..b27ea1e 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -3203,6 +3203,9 @@ initial(void)
 		debug_info = TRUE;
 	}
 
+	if (!get_value_for_old_linux())
+		return FALSE;
+
 out:
 	if (!info->page_size) {
 		/*
@@ -3306,9 +3309,6 @@ out:
 			return FALSE;
 	}
 
-	if (!get_value_for_old_linux())
-		return FALSE;
-
 	/* use buddy identification of free pages whether cyclic or not */
 	/* (this can reduce pages scan of 1TB memory from 60sec to 30sec) */
 	if (info->dump_level & DL_EXCLUDE_FREE)
-- 
1.9.0