On 2023-05-10 03:09, HAGIO KAZUHITO(萩尾 一仁) wrote:
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From: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
The current comparison macros for kernel version shift minor number only
8 bits. This can cause an unexpected result on kernels with revision
number over 255, e.g. Linux 4.14.314.
In fact, on Linux 4.14.314 for x86_64 without CONFIG_RANDOMIZE_BASE=y
(KASLR), the following condition became false in x86_64_init().
((THIS_KERNEL_VERSION >= LINUX(4,14,84)) &&
(THIS_KERNEL_VERSION < LINUX(4,15,0)))
As a result, crash used a wrong hard-coded value for PAGE_OFFSET and
failed to start a session with the following seek error.
crash: seek error: physical address: 200e000 type: "pud page"
Shift the major and minor number by 24 and 16 bits respectively to fix
this issue.
This fixes the issue for me. The only detail is that I couldn't apply
this patch to latest crash HEAD 2505a65ff5471 so I applied it manually.
Thank you very much, Kazu!
Tested-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
- Luiz
Reported-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
Signed-off-by: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
---
defs.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/defs.h b/defs.h
index 12ad6aaa0998..211fc9d55d33 100644
--- a/defs.h
+++ b/defs.h
@@ -807,10 +807,10 @@ struct kernel_table { /* kernel data */
} \
}
-#define THIS_KERNEL_VERSION ((kt->kernel_version[0] << 16) + \
- (kt->kernel_version[1] << 8) + \
+#define THIS_KERNEL_VERSION ((kt->kernel_version[0] << 24) + \
+ (kt->kernel_version[1] << 16) + \
(kt->kernel_version[2]))
-#define LINUX(x,y,z) (((uint)(x) << 16) + ((uint)(y) << 8) + (uint)(z))
+#define LINUX(x,y,z) (((uint)(x) << 24) + ((uint)(y) << 16) + (uint)(z))
#define THIS_GCC_VERSION ((kt->gcc_version[0] << 16) + \
(kt->gcc_version[1] << 8) + \
--
2.31.1
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