| Message ID | 20230530110328.2213762-1-mark.rutland@arm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | arm64: module: improve module VA range selection | expand |
Hi Mark, I've reviewed and verified on NVIDIA server platforms w/ and w/o KASLR feature is disabled. root@localhost:~# dmesg | grep -E "Modules:|KASLR" [ 0.000000] KASLR disabled on command line [ 5.961360] Modules: 1223 pages in range for non-PLT usage [ 5.961362] Modules: 31943 pages in range for PLT usage Looks good to me. Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> On 5/30/23 06:03, Mark Rutland wrote: > External email: Use caution opening links or attachments > > > This series (based on v6.4-rc3) aims to make arm64's module allocation > code more robust. To that end: > > * Redundant code for KASAN && !KASAN_VMALLOC is removed, as this > combination is no longer possible. > > * Module PLT support is mandated, always allowing for the use of a 2G > module region. Practically speaking, this is already the case for almost > all users as module PLT support is mandated by both KASLR (which most > distros including Android, enable this), and by the workaround for ARM > erratum 843419 (required by Cortex-A53). > > * The module VA region selection is moved to module.c, making it > self-contained and easier to follow. > > * The default module VA region is expanded to 2G. This ensures that > there is sufficient space for the full region using PLTs even when > KASLR is disabled or no seed provided. > > * The module VA range init code is updated to log when the kernel is too > large to support the use of a 128M or 2G module region, to enable > debugging of these cases. Contemporary kernels built with debug > options can be bigger than 128M, and a kernel bigger than 2G is > unlikely but theoretically possible. Adding this logging should help > to debug or filter away reports for such cases. > > This should allow for loading of very large modules, as Shanker reported > was an issue: > > https://lore.kernel.org/linux-arm-kernel/20230326170756.3021936-1-sdonthineni@nvidia.com/ > https://lore.kernel.org/linux-arm-kernel/20230330140437.984211-1-sdonthineni@nvidia.com/ > > ... and as Ard had an alternative series for: > > https://lore.kernel.org/linux-arm-kernel/20230404135437.2744866-1-ardb@kernel.org/ > > Since v1 [1]: > * Log the number of pages in range > * Remove unused kasan_mod_shadow_end > * Only randomize when kaslr_enabled() > * Simplify control-flow > > Since v2 [2]: > * Apply Ard's Reviewed-by tags > * Fix typos > * Rebave to v6.4-rc3 (trivial) > > [1] https://lore.kernel.org/linux-arm-kernel/20230509111451.4184972-1-mark.rutland@arm.com/ > [2] https://lore.kernel.org/linux-arm-kernel/20230512152210.3072475-1-mark.rutland@arm.com/ > > Thanks, > Mark. > > Mark Rutland (6): > arm64: module: remove old !KASAN_VMALLOC logic > arm64: kasan: remove !KASAN_VMALLOC remnants > arm64: kaslr: split kaslr/module initialization > arm64: module: move module randomization to module.c > arm64: module: mandate MODULE_PLTS > arm64: module: rework module VA range selection > > Documentation/arm64/memory.rst | 8 +- > arch/arm64/Kconfig | 28 +---- > arch/arm64/include/asm/memory.h | 16 +-- > arch/arm64/include/asm/module.h | 8 -- > arch/arm64/include/asm/module.lds.h | 2 - > arch/arm64/kernel/Makefile | 3 +- > arch/arm64/kernel/ftrace.c | 8 +- > arch/arm64/kernel/kaslr.c | 83 +++------------ > arch/arm64/kernel/module.c | 159 +++++++++++++++++++++------- > arch/arm64/kernel/setup.c | 2 + > arch/arm64/mm/kasan_init.c | 17 +-- > 11 files changed, 159 insertions(+), 175 deletions(-) > > -- > 2.30.2 >
On Tue, 30 May 2023 12:03:22 +0100, Mark Rutland wrote: > This series (based on v6.4-rc3) aims to make arm64's module allocation > code more robust. To that end: > > * Redundant code for KASAN && !KASAN_VMALLOC is removed, as this > combination is no longer possible. > > * Module PLT support is mandated, always allowing for the use of a 2G > module region. Practically speaking, this is already the case for almost > all users as module PLT support is mandated by both KASLR (which most > distros including Android, enable this), and by the workaround for ARM > erratum 843419 (required by Cortex-A53). > > [...] Applied to arm64 (for-next/module-alloc), thanks! [1/6] arm64: module: remove old !KASAN_VMALLOC logic https://git.kernel.org/arm64/c/8339f7d8e178 [2/6] arm64: kasan: remove !KASAN_VMALLOC remnants https://git.kernel.org/arm64/c/55123afffe93 [3/6] arm64: kaslr: split kaslr/module initialization https://git.kernel.org/arm64/c/6e13b6b923b3 [4/6] arm64: module: move module randomization to module.c https://git.kernel.org/arm64/c/e46b7103aef3 [5/6] arm64: module: mandate MODULE_PLTS https://git.kernel.org/arm64/c/ea3752ba9685 [6/6] arm64: module: rework module VA range selection https://git.kernel.org/arm64/c/3e35d303ab7d