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| author | Mark Rutland <mark.rutland@arm.com> | 2020-11-03 11:22:29 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-11-10 18:30:40 +0100 |
| commit | 833be850f1cabd0e3b5337c0fcab20a6e936dd48 (patch) | |
| tree | f19034fb5146f82b4fc2944ec86fef62581335aa /arch/arm64/kernel/setup.c | |
| parent | arm64: kprobes: Remove redundant kprobe_step_ctx (diff) | |
| download | linux-833be850f1cabd0e3b5337c0fcab20a6e936dd48.tar.xz linux-833be850f1cabd0e3b5337c0fcab20a6e936dd48.zip | |
arm64: consistently use reserved_pg_dir
Depending on configuration options and specific code paths, we either
use the empty_zero_page or the configuration-dependent reserved_ttbr0
as a reserved value for TTBR{0,1}_EL1.
To simplify this code, let's always allocate and use the same
reserved_pg_dir, replacing reserved_ttbr0. Note that this is allocated
(and hence pre-zeroed), and is also marked as read-only in the kernel
Image mapping.
Keeping this separate from the empty_zero_page potentially helps with
robustness as the empty_zero_page is used in a number of cases where a
failure to map it read-only could allow it to become corrupted.
The (presently unused) swapper_pg_end symbol is also removed, and
comments are added wherever we rely on the offsets between the
pre-allocated pg_dirs to keep these cases easily identifiable.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201103102229.8542-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/setup.c')
| -rw-r--r-- | arch/arm64/kernel/setup.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 133257ffd859..c28a9ec76b11 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -366,7 +366,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) * faults in case uaccess_enable() is inadvertently called by the init * thread. */ - init_task.thread_info.ttbr0 = __pa_symbol(empty_zero_page); + init_task.thread_info.ttbr0 = __pa_symbol(reserved_pg_dir); #endif if (boot_args[1] || boot_args[2] || boot_args[3]) { |