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| author | Alexander Gordeev <agordeev@linux.ibm.com> | 2024-08-21 19:55:07 +0300 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2024-08-22 20:24:13 +0300 |
| commit | 1642285e511c2a40b14e87a41aa8feace6123036 (patch) | |
| tree | 90e1cde79647a5e9f4b3fa8a66fb7bf215787b65 /arch/s390/include/asm/page.h | |
| parent | d7fd2941ae9a67423d1c7bee985f240e4686634f (diff) | |
| download | linux-1642285e511c2a40b14e87a41aa8feace6123036.tar.xz | |
s390/boot: Fix KASLR base offset off by __START_KERNEL bytes
Symbol offsets to the KASLR base do not match symbol address in
the vmlinux image. That is the result of setting the KASLR base
to the beginning of .text section as result of an optimization.
Revert that optimization and allocate virtual memory for the
whole kernel image including __START_KERNEL bytes as per the
linker script. That allows keeping the semantics of the KASLR
base offset in sync with other architectures.
Rename __START_KERNEL to TEXT_OFFSET, since it represents the
offset of the .text section within the kernel image, rather than
a virtual address.
Still skip mapping TEXT_OFFSET bytes to save memory on pgtables
and provoke exceptions in case an attempt to access this area is
made, as no kernel symbol may reside there.
In case CONFIG_KASAN is enabled the location counter might exceed
the value of TEXT_OFFSET, while the decompressor linker script
forcefully resets it to TEXT_OFFSET, which leads to a sections
overlap link failure. Use MAX() expression to avoid that.
Reported-by: Omar Sandoval <osandov@osandov.com>
Closes: https://lore.kernel.org/linux-s390/ZnS8dycxhtXBZVky@telecaster.dhcp.thefacebook.com/
Fixes: 56b1069c40c7 ("s390/boot: Rework deployment of the kernel image")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/page.h')
| -rw-r--r-- | arch/s390/include/asm/page.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h index 06416b3f94f5..16e4caa931f1 100644 --- a/arch/s390/include/asm/page.h +++ b/arch/s390/include/asm/page.h @@ -279,8 +279,9 @@ static inline unsigned long virt_to_pfn(const void *kaddr) #define AMODE31_SIZE (3 * PAGE_SIZE) #define KERNEL_IMAGE_SIZE (512 * 1024 * 1024) -#define __START_KERNEL 0x100000 #define __NO_KASLR_START_KERNEL CONFIG_KERNEL_IMAGE_BASE #define __NO_KASLR_END_KERNEL (__NO_KASLR_START_KERNEL + KERNEL_IMAGE_SIZE) +#define TEXT_OFFSET 0x100000 + #endif /* _S390_PAGE_H */ |