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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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5bd5a45266
This patch expands functionality of CONFIG_DEBUG_RODATA to set main (static) kernel data area as NX. The following steps are taken to achieve this: 1. Linker script is adjusted so .text always starts and ends on a page bound 2. Linker script is adjusted so .rodata always start and end on a page boundary 3. NX is set for all pages from _etext through _end in mark_rodata_ro. 4. free_init_pages() sets released memory NX in arch/x86/mm/init.c 5. bios rom is set to x when pcibios is used. The results of patch application may be observed in the diff of kernel page table dumps: pcibios: -- data_nx_pt_before.txt 2009-10-13 07:48:59.000000000 -0400 ++ data_nx_pt_after.txt 2009-10-13 07:26:46.000000000 -0400 0x00000000-0xc0000000 3G pmd ---[ Kernel Mapping ]--- -0xc0000000-0xc0100000 1M RW GLB x pte +0xc0000000-0xc00a0000 640K RW GLB NX pte +0xc00a0000-0xc0100000 384K RW GLB x pte -0xc0100000-0xc03d7000 2908K ro GLB x pte +0xc0100000-0xc0318000 2144K ro GLB x pte +0xc0318000-0xc03d7000 764K ro GLB NX pte -0xc03d7000-0xc0600000 2212K RW GLB x pte +0xc03d7000-0xc0600000 2212K RW GLB NX pte 0xc0600000-0xf7a00000 884M RW PSE GLB NX pmd 0xf7a00000-0xf7bfe000 2040K RW GLB NX pte 0xf7bfe000-0xf7c00000 8K pte No pcibios: -- data_nx_pt_before.txt 2009-10-13 07:48:59.000000000 -0400 ++ data_nx_pt_after.txt 2009-10-13 07:26:46.000000000 -0400 0x00000000-0xc0000000 3G pmd ---[ Kernel Mapping ]--- -0xc0000000-0xc0100000 1M RW GLB x pte +0xc0000000-0xc0100000 1M RW GLB NX pte -0xc0100000-0xc03d7000 2908K ro GLB x pte +0xc0100000-0xc0318000 2144K ro GLB x pte +0xc0318000-0xc03d7000 764K ro GLB NX pte -0xc03d7000-0xc0600000 2212K RW GLB x pte +0xc03d7000-0xc0600000 2212K RW GLB NX pte 0xc0600000-0xf7a00000 884M RW PSE GLB NX pmd 0xf7a00000-0xf7bfe000 2040K RW GLB NX pte 0xf7bfe000-0xf7c00000 8K pte The patch has been originally developed for Linux 2.6.34-rc2 x86 by Siarhei Liakh <sliakh.lkml@gmail.com> and Xuxian Jiang <jiang@cs.ncsu.edu>. -v1: initial patch for 2.6.30 -v2: patch for 2.6.31-rc7 -v3: moved all code into arch/x86, adjusted credits -v4: fixed ifdef, removed credits from CREDITS -v5: fixed an address calculation bug in mark_nxdata_nx() -v6: added acked-by and PT dump diff to commit log -v7: minor adjustments for -tip -v8: rework with the merge of "Set first MB as RW+NX" Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr> Cc: Arjan van de Ven <arjan@infradead.org> Cc: James Morris <jmorris@namei.org> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F82E.60601@free.fr> [ minor cleanliness edits ] Signed-off-by: Ingo Molnar <mingo@elte.hu> |
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