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| author | Barry Song <song.bao.hua@hisilicon.com> | 2021-07-31 00:51:31 +1200 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-08-03 10:36:42 +0100 |
| commit | f9c4ff2ab9fe433d44ebbc2e3c2368a49df44798 (patch) | |
| tree | 52fdeb8ee023e4378c6a54cd8b63f6a9b63625fb /arch/arm64/kernel | |
| parent | 64ee84c75b5f75132eec97f2c7a201a056d53698 (diff) | |
| download | linux-f9c4ff2ab9fe433d44ebbc2e3c2368a49df44798.tar.bz2 | |
arm64: fix the doc of RANDOMIZE_MODULE_REGION_FULL
Obviously kaslr is setting the module region to 2GB rather than 4GB since
commit b2eed9b588112 ("arm64/kernel: kaslr: reduce module randomization
range to 2 GB"). So fix the size of region in Kconfig.
On the other hand, even though RANDOMIZE_MODULE_REGION_FULL is not set,
module_alloc() can fall back to a 2GB window if ARM64_MODULE_PLTS is set.
In this case, veneers are still needed. !RANDOMIZE_MODULE_REGION_FULL
doesn't necessarily mean veneers are not needed.
So fix the doc to be more precise to avoid any confusion to the readers
of the code.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210730125131.13724-1-song.bao.hua@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/kaslr.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c index cfa2cfde3019..418b2bba1521 100644 --- a/arch/arm64/kernel/kaslr.c +++ b/arch/arm64/kernel/kaslr.c @@ -162,7 +162,9 @@ u64 __init kaslr_early_init(void) * a PAGE_SIZE multiple in the range [_etext - MODULES_VSIZE, * _stext) . This guarantees that the resulting region still * covers [_stext, _etext], and that all relative branches can - * be resolved without veneers. + * be resolved without veneers unless this region is exhausted + * and we fall back to a larger 2GB window in module_alloc() + * when ARM64_MODULE_PLTS is enabled. */ module_range = MODULES_VSIZE - (u64)(_etext - _stext); module_alloc_base = (u64)_etext + offset - MODULES_VSIZE; |