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| author |   Vasily Gorbik <gor@linux.ibm.com> | 2017-11-20 12:56:10 +0100 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-10-09 11:21:29 +0200 |
| commit | 135ff163939294f5573927ca890699ed619c0031 (patch) | |
| tree | 9f2db851306f6dfdc58dc2249677507e560feeef /arch/s390/mm | |
| parent | s390/kasan: enable stack and global variables access checks (diff) | |
| download | linux-dev-135ff163939294f5573927ca890699ed619c0031.tar.xz linux-dev-135ff163939294f5573927ca890699ed619c0031.zip | |
s390/kasan: free early identity mapping structures
Kasan initialization code is changed to populate persistent shadow
first, save allocator position into pgalloc_freeable and proceed with
early identity mapping creation. This way early identity mapping paging
structures could be freed at once after switching to swapper_pg_dir
when early identity mapping is not needed anymore.
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
| -rw-r--r-- | arch/s390/mm/init.c | 1 | ||||
| -rw-r--r-- | arch/s390/mm/kasan_init.c | 12 |
2 files changed, 11 insertions, 2 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 50ebda9b3d0c..92d7a153e72a 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -109,6 +109,7 @@ void __init paging_init(void) psw_bits(psw).dat = 1; psw_bits(psw).as = PSW_BITS_AS_HOME; __load_psw_mask(psw.mask); + kasan_free_early_identity(); sparse_memory_present_with_active_regions(MAX_NUMNODES); sparse_init(); diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c index e4697900e884..40748afc43fa 100644 --- a/arch/s390/mm/kasan_init.c +++ b/arch/s390/mm/kasan_init.c @@ -15,6 +15,7 @@ static unsigned long segment_pos __initdata; static unsigned long segment_low __initdata; static unsigned long pgalloc_pos __initdata; static unsigned long pgalloc_low __initdata; +static unsigned long pgalloc_freeable __initdata; static bool has_edat __initdata; static bool has_nx __initdata; @@ -298,14 +299,16 @@ void __init kasan_early_init(void) * | 2Gb | \| unmapped | allocated per module * +-----------------+ +- shadow end ---+ */ - /* populate identity mapping */ - kasan_early_vmemmap_populate(0, memsize, POPULATE_ONE2ONE); /* populate kasan shadow (for identity mapping and zero page mapping) */ kasan_early_vmemmap_populate(__sha(0), __sha(memsize), POPULATE_MAP); if (IS_ENABLED(CONFIG_MODULES)) untracked_mem_end = vmax - MODULES_LEN; kasan_early_vmemmap_populate(__sha(memsize), __sha(untracked_mem_end), POPULATE_ZERO_SHADOW); + /* memory allocated for identity mapping structs will be freed later */ + pgalloc_freeable = pgalloc_pos; + /* populate identity mapping */ + kasan_early_vmemmap_populate(0, memsize, POPULATE_ONE2ONE); kasan_set_pgd(early_pg_dir, asce_type); kasan_enable_dat(); /* enable kasan */ @@ -345,3 +348,8 @@ void __init kasan_copy_shadow(pgd_t *pg_dir) memcpy(pu_dir_dst, pu_dir_src, (KASAN_SHADOW_SIZE >> PUD_SHIFT) * sizeof(pud_t)); } + +void __init kasan_free_early_identity(void) +{ + memblock_free(pgalloc_pos, pgalloc_freeable - pgalloc_pos); +} |