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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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3b10d0095a
ISA 3 defines new encoded access authority that allows instruction access prevention in privileged mode and allows normal access to problem state. This patch just enables IAMR (Instruction Authority Mask Register), enabling AMR would require more work. I've tested this with a buggy driver and a simple payload. The payload is specific to the build I've tested. mpe: Also tested with LKDTM: # echo EXEC_USERSPACE > /sys/kernel/debug/provoke-crash/DIRECT lkdtm: Performing direct entry EXEC_USERSPACE lkdtm: attempting ok execution at c0000000005bf560 lkdtm: attempting bad execution at 00003fff8d940000 Unable to handle kernel paging request for instruction fetch Faulting instruction address: 0x3fff8d940000 Oops: Kernel access of bad area, sig: 11 [#1] NIP: 00003fff8d940000 LR: c0000000005bfa58 CTR: 00003fff8d940000 REGS: c0000000f1fcf900 TRAP: 0400 Not tainted (4.9.0-rc5-compiler_gcc-6.2.0-00109-g956dbc06232a) MSR: 9000000010009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 48002222 XER: 00000000 ... Call Trace: lkdtm_EXEC_USERSPACE+0x104/0x120 (unreliable) lkdtm_do_action+0x3c/0x80 direct_entry+0x100/0x1b0 full_proxy_write+0x94/0x100 __vfs_write+0x3c/0x1b0 vfs_write+0xcc/0x230 SyS_write+0x60/0x110 system_call+0x38/0xfc Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
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| boot | ||
| configs | ||
| crypto | ||
| include | ||
| kernel | ||
| kvm | ||
| lib | ||
| math-emu | ||
| mm | ||
| net | ||
| oprofile | ||
| perf | ||
| platforms | ||
| scripts | ||
| sysdev | ||
| xmon | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||
| relocs_check.sh | ||