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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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bd49e16e33
With vsyscall emulation on, a readable vsyscall page is still exposed that contains syscall instructions that validly implement the vsyscalls. This is required because certain dynamic binary instrumentation tools attempt to read the call targets of call instructions in the instrumented code. If the instrumented code uses vsyscalls, then the vsyscall page needs to contain readable code. Unfortunately, leaving readable memory at a deterministic address can be used to help various ASLR bypasses, so some hardening value can be gained by disallowing vsyscall reads. Given how rarely the vsyscall page needs to be readable, add a mechanism to make the vsyscall page be execute only. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/d17655777c21bc09a7af1bbcf74e6f2b69a51152.1561610354.git.luto@kernel.org |
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| .. | ||
| syscalls | ||
| vdso | ||
| vsyscall | ||
| calling.h | ||
| common.c | ||
| entry_32.S | ||
| entry_64_compat.S | ||
| entry_64.S | ||
| Makefile | ||
| syscall_32.c | ||
| syscall_64.c | ||
| thunk_32.S | ||
| thunk_64.S | ||