mirror of https://gitee.com/openkylin/linux.git
dd71a17b11
Currently when setting up an IMR around the kernel's .text section we lock that IMR, preventing further modification. While superficially this appears to be the right thing to do, in fact this doesn't account for a legitimate change in the memory map such as when executing a new kernel via kexec. In such a scenario a second kernel can have a different size and location to it's predecessor and can view some of the memory occupied by it's predecessor as legitimately usable DMA RAM. If this RAM were then subsequently allocated to DMA agents within the system it could conceivably trigger an IMR violation. This patch fixes the this potential situation by keeping the kernel's .text section IMR lock bit false by default. Suggested-by: Ingo Molnar <mingo@kernel.org> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boon.leong.ong@intel.com Cc: paul.gortmaker@windriver.com Link: http://lkml.kernel.org/r/1456190999-12685-2-git-send-email-pure.logic@nexus-software.ie Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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| Makefile | ||
| imr.c | ||
| imr_selftest.c | ||