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| author | Huang Shijie <shijie@os.amperecomputing.com> | 2025-09-09 11:32:35 +0800 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2025-09-16 20:53:13 +0100 |
| commit | c0f303d7d4723b01c686e949e6f26a93e5cda910 (patch) | |
| tree | 3dd6d9d1c2fd63e279d6c722c2ad04150d962609 | |
| parent | arm64: mm: Represent physical memory with phys_addr_t and resource_size_t (diff) | |
| download | linux-c0f303d7d4723b01c686e949e6f26a93e5cda910.tar.gz linux-c0f303d7d4723b01c686e949e6f26a93e5cda910.zip | |
arm64: mm: Rework the 'rodata=' options
As per admin guide documentation, "rodata=on" should be the default on
platforms. Documentation/admin-guide/kernel-parameters.txt describes
these options as
rodata= [KNL,EARLY]
on Mark read-only kernel memory as read-only (default).
off Leave read-only kernel memory writable for debugging.
full Mark read-only kernel memory and aliases as read-only
[arm64]
But on arm64 platform, RODATA_FULL_DEFAULT_ENABLED is enabled by default,
so "rodata=full" is the default instead.
For parity with other architectures, namely x86, rework 'rodata=on' to
match the current "full" behaviour and replace 'rodata=full' with a new
'rodata=noalias' option which retains writable aliases in the direct map
for memory regions outside of the kernel image.
Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 | ||||
| -rw-r--r-- | arch/arm64/include/asm/setup.h | 4 |
2 files changed, 5 insertions, 4 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 747a55abf494..fe99652c584e 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6405,8 +6405,9 @@ rodata= [KNL,EARLY] on Mark read-only kernel memory as read-only (default). off Leave read-only kernel memory writable for debugging. - full Mark read-only kernel memory and aliases as read-only - [arm64] + noalias Mark read-only kernel memory as read-only but retain + writable aliases in the direct map for regions outside + of the kernel image. [arm64] rockchip.usb_uart [EARLY] diff --git a/arch/arm64/include/asm/setup.h b/arch/arm64/include/asm/setup.h index ba269a7a3201..3d96dde4d214 100644 --- a/arch/arm64/include/asm/setup.h +++ b/arch/arm64/include/asm/setup.h @@ -21,7 +21,7 @@ static inline bool arch_parse_debug_rodata(char *arg) if (!arg) return false; - if (!strcmp(arg, "full")) { + if (!strcmp(arg, "on")) { rodata_enabled = rodata_full = true; return true; } @@ -31,7 +31,7 @@ static inline bool arch_parse_debug_rodata(char *arg) return true; } - if (!strcmp(arg, "on")) { + if (!strcmp(arg, "noalias")) { rodata_enabled = true; rodata_full = false; return true; |