Hello Hari,
On 23/01/25 15:34, Hari Bathini wrote:
On 21/01/25 5:24 pm, Sourabh Jain wrote:
kexec_elf_load() loads an ELF executable and sets the address of the
lowest PT_LOAD section to the address held by the lowest_load_addr
function argument.
To determine the lowest PT_LOAD address, a local variable lowest_addr
(type unsigned long) is initialized to UINT_MAX. After loading each
PT_LOAD, its address is compared to lowest_addr. If a loaded PT_LOAD
address is lower, lowest_addr is updated. However, setting lowest_addr
to UINT_MAX won't work when the kernel image is loaded above 4G, as the
returned lowest PT_LOAD address would be invalid. This is resolved by
initializing lowest_addr to ULONG_MAX instead.
This issue was discovered while implementing crashkernel high/low
reservation on the PowerPC architecture.
Acked-by: Hari Bathini <hbathini@xxxxxxxxxxxxx>
Thanks for the Ack!
- Sourabh Jain
Fixes: a0458284f062 ("powerpc: Add support code for kexec_file_load()")
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Hari Bathini <hbathini@xxxxxxxxxxxxx>
Cc: Madhavan Srinivasan <maddy@xxxxxxxxxxxxx>
Cc: Mahesh Salgaonkar <mahesh@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: kexec@xxxxxxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Signed-off-by: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx>
---
kernel/kexec_elf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/kexec_elf.c b/kernel/kexec_elf.c
index d3689632e8b9..3a5c25b2adc9 100644
--- a/kernel/kexec_elf.c
+++ b/kernel/kexec_elf.c
@@ -390,7 +390,7 @@ int kexec_elf_load(struct kimage *image, struct
elfhdr *ehdr,
struct kexec_buf *kbuf,
unsigned long *lowest_load_addr)
{
- unsigned long lowest_addr = UINT_MAX;
+ unsigned long lowest_addr = ULONG_MAX;
int ret;
size_t i;
