From 22c43f36b5cf22a7e4506cb3a53f3ad2a43f60f7 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 20 Jan 2016 22:13:41 +0200 Subject: x86/platform/quark: Print boundaries correctly When we print values, such as @size, we have to understand that it's derived from [begin .. end] as: size = end - begin + 1 On the opposite the @end is derived from the rest as: end = begin + size - 1 Correct the IMR code to print values correctly. Note that @__end_rodata actually points to the next address after the aligned .rodata section. Signed-off-by: Andy Shevchenko Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Ong, Boon Leong Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1453320821-64328-1-git-send-email-andriy.shevchenko@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/platform/intel-quark/imr.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'arch/x86/platform/intel-quark/imr.c') diff --git a/arch/x86/platform/intel-quark/imr.c b/arch/x86/platform/intel-quark/imr.c index 0ee619f9fcb7..ad5ec6f784e8 100644 --- a/arch/x86/platform/intel-quark/imr.c +++ b/arch/x86/platform/intel-quark/imr.c @@ -228,11 +228,12 @@ static int imr_dbgfs_state_show(struct seq_file *s, void *unused) if (imr_is_enabled(&imr)) { base = imr_to_phys(imr.addr_lo); end = imr_to_phys(imr.addr_hi) + IMR_MASK; + size = end - base + 1; } else { base = 0; end = 0; + size = 0; } - size = end - base; seq_printf(s, "imr%02i: base=%pa, end=%pa, size=0x%08zx " "rmask=0x%08x, wmask=0x%08x, %s, %s\n", i, &base, &end, size, imr.rmask, imr.wmask, @@ -587,6 +588,7 @@ static void __init imr_fixup_memmap(struct imr_device *idev) { phys_addr_t base = virt_to_phys(&_text); size_t size = virt_to_phys(&__end_rodata) - base; + unsigned long start, end; int i; int ret; @@ -594,18 +596,24 @@ static void __init imr_fixup_memmap(struct imr_device *idev) for (i = 0; i < idev->max_imr; i++) imr_clear(i); + start = (unsigned long)_text; + end = (unsigned long)__end_rodata - 1; + /* * Setup a locked IMR around the physical extent of the kernel * from the beginning of the .text secton to the end of the * .rodata section as one physically contiguous block. + * + * We don't round up @size since it is already PAGE_SIZE aligned. + * See vmlinux.lds.S for details. */ ret = imr_add_range(base, size, IMR_CPU, IMR_CPU, true); if (ret < 0) { - pr_err("unable to setup IMR for kernel: (%p - %p)\n", - &_text, &__end_rodata); + pr_err("unable to setup IMR for kernel: %zu KiB (%lx - %lx)\n", + size / 1024, start, end); } else { - pr_info("protecting kernel .text - .rodata: %zu KiB (%p - %p)\n", - size / 1024, &_text, &__end_rodata); + pr_info("protecting kernel .text - .rodata: %zu KiB (%lx - %lx)\n", + size / 1024, start, end); } } -- cgit v1.2.3 From dd71a17b1193dd4a4c35ecd0ba227aac3d110836 Mon Sep 17 00:00:00 2001 From: Bryan O'Donoghue Date: Tue, 23 Feb 2016 01:29:58 +0000 Subject: x86/platform/intel/quark: Change the kernel's IMR lock bit to false 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 Reported-by: Andy Shevchenko Signed-off-by: Bryan O'Donoghue Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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 --- arch/x86/platform/intel-quark/imr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/platform/intel-quark/imr.c') diff --git a/arch/x86/platform/intel-quark/imr.c b/arch/x86/platform/intel-quark/imr.c index c61b6c332e97..bfadcd0f4944 100644 --- a/arch/x86/platform/intel-quark/imr.c +++ b/arch/x86/platform/intel-quark/imr.c @@ -592,14 +592,14 @@ static void __init imr_fixup_memmap(struct imr_device *idev) end = (unsigned long)__end_rodata - 1; /* - * Setup a locked IMR around the physical extent of the kernel + * Setup an unlocked IMR around the physical extent of the kernel * from the beginning of the .text secton to the end of the * .rodata section as one physically contiguous block. * * We don't round up @size since it is already PAGE_SIZE aligned. * See vmlinux.lds.S for details. */ - ret = imr_add_range(base, size, IMR_CPU, IMR_CPU, true); + ret = imr_add_range(base, size, IMR_CPU, IMR_CPU, false); if (ret < 0) { pr_err("unable to setup IMR for kernel: %zu KiB (%lx - %lx)\n", size / 1024, start, end); -- cgit v1.2.3