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s390/boot: Do not rescue .vmlinux.relocs section

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The .vmlinux.relocs section is moved in front of the compressed
kernel. The interim section rescue step is avoided as result.

Suggested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Alexander Gordeev 2024-02-26 11:47:40 +01:00
parent 56b1069c40
commit 236d70f82b
3 changed files with 22 additions and 41 deletions
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35
arch/s390/boot/startup.c
View File

@ -185,26 +185,7 @@ static void kaslr_adjust_relocs(unsigned long min_addr, unsigned long max_addr,
}
static void kaslr_adjust_got(unsigned long offset) {}
static void rescue_relocs(void) {}
static void free_relocs(void) {}
#else
static int *vmlinux_relocs_64_start;
static int *vmlinux_relocs_64_end;
static void rescue_relocs(void)
{
unsigned long size = __vmlinux_relocs_64_end - __vmlinux_relocs_64_start;
vmlinux_relocs_64_start = (void *)physmem_alloc_top_down(RR_RELOC, size, 0);
vmlinux_relocs_64_end = (void *)vmlinux_relocs_64_start + size;
memmove(vmlinux_relocs_64_start, __vmlinux_relocs_64_start, size);
}
static void free_relocs(void)
{
physmem_free(RR_RELOC);
}
static void kaslr_adjust_relocs(unsigned long min_addr, unsigned long max_addr,
unsigned long offset, unsigned long phys_offset)
{
@ -212,7 +193,7 @@ static void kaslr_adjust_relocs(unsigned long min_addr, unsigned long max_addr,
long loc;
/* Adjust R_390_64 relocations */
for (reloc = vmlinux_relocs_64_start; reloc < vmlinux_relocs_64_end; reloc++) {
for (reloc = (int *)__vmlinux_relocs_64_start; reloc < (int *)__vmlinux_relocs_64_end; reloc++) {
loc = (long)*reloc + phys_offset;
if (loc < min_addr || loc > max_addr)
error("64-bit relocation outside of kernel!\n");
@ -486,7 +467,6 @@ void startup_kernel(void)
detect_physmem_online_ranges(max_physmem_end);
save_ipl_cert_comp_list();
rescue_initrd(safe_addr, ident_map_size);
rescue_relocs();
if (kaslr_enabled())
__kaslr_offset_phys = randomize_within_range(kernel_size, THREAD_SIZE, 0, ident_map_size);
@ -498,6 +478,18 @@ void startup_kernel(void)
/* vmlinux decompression is done, shrink reserved low memory */
physmem_reserve(RR_DECOMPRESSOR, 0, (unsigned long)_decompressor_end);
/*
* In case KASLR is enabled the randomized location of .amode31
* section might overlap with .vmlinux.relocs section. To avoid that
* the below randomize_within_range() could have been called with
* __vmlinux_relocs_64_end as the lower range address. However,
* .amode31 section is written to by the decompressed kernel - at
* that time the contents of .vmlinux.relocs is not needed anymore.
* Conversly, .vmlinux.relocs is read only by the decompressor, even
* before the kernel started. Therefore, in case the two sections
* overlap there is no risk of corrupting any data.
*/
if (kaslr_enabled())
amode31_lma = randomize_within_range(vmlinux.amode31_size, PAGE_SIZE, 0, SZ_2G);
if (!amode31_lma)
@ -521,7 +513,6 @@ void startup_kernel(void)
kaslr_adjust_relocs(__kaslr_offset_phys, __kaslr_offset_phys + vmlinux.image_size,
__kaslr_offset, __kaslr_offset_phys);
kaslr_adjust_got(__kaslr_offset);
free_relocs();
setup_vmem(__kaslr_offset, __kaslr_offset + kernel_size, asce_limit);
copy_bootdata();

27
arch/s390/boot/vmlinux.lds.S
View File

@ -99,6 +99,15 @@ SECTIONS
_decompressor_end = .;
#ifndef CONFIG_PIE_BUILD
. = ALIGN(4);
.vmlinux.relocs : {
__vmlinux_relocs_64_start = .;
*(.vmlinux.relocs_64)
__vmlinux_relocs_64_end = .;
}
#endif
#ifdef CONFIG_KERNEL_UNCOMPRESSED
. = ALIGN(PAGE_SIZE);
. += AMODE31_SIZE; /* .amode31 section */
@ -111,24 +120,6 @@ SECTIONS
_compressed_end = .;
}
#ifndef CONFIG_PIE_BUILD
/*
* When the kernel is built with CONFIG_KERNEL_UNCOMPRESSED, the entire
* uncompressed vmlinux.bin is positioned in the bzImage decompressor
* image at the default kernel LMA of 0x100000, enabling it to be
* executed in-place. However, the size of .vmlinux.relocs could be
* large enough to cause an overlap with the uncompressed kernel at the
* address 0x100000. To address this issue, .vmlinux.relocs is
* positioned after the .rodata.compressed.
*/
. = ALIGN(4);
.vmlinux.relocs : {
__vmlinux_relocs_64_start = .;
*(.vmlinux.relocs_64)
__vmlinux_relocs_64_end = .;
}
#endif
#define SB_TRAILER_SIZE 32
/* Trailer needed for Secure Boot */
. += SB_TRAILER_SIZE; /* make sure .sb.trailer does not overwrite the previous section */

1
arch/s390/include/asm/physmem_info.h
View File

@ -22,7 +22,6 @@ enum reserved_range_type {
RR_DECOMPRESSOR,
RR_INITRD,
RR_VMLINUX,
RR_RELOC,
RR_AMODE31,
RR_IPLREPORT,
RR_CERT_COMP_LIST,