From bad1a753d4d4deb09d4bc0bac1dd4fc3298502e9 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" <hjl.tools@gmail.com> Date: Mon, 21 May 2012 20:29:45 -0700 Subject: [PATCH] x86, x32, ptrace: Remove PTRACE_ARCH_PRCTL for x32 When I added x32 ptrace to 3.4 kernel, I also include PTRACE_ARCH_PRCTL support for x32 GDB For ARCH_GET_FS/GS, it takes a pointer to int64. But at user level, ARCH_GET_FS/GS takes a pointer to int32. So I have to add x32 ptrace to glibc to handle it with a temporary int64 passed to kernel and copy it back to GDB as int32. Roland suggested that PTRACE_ARCH_PRCTL is obsolete and x32 GDB should use fs_base and gs_base fields of user_regs_struct instead. Accordingly, remove PTRACE_ARCH_PRCTL completely from the x32 code to avoid possible memory overrun when pointer to int32 is passed to kernel. Link: http://lkml.kernel.org/r/CAMe9rOpDzHfS7NH7m1vmD9QRw8SSj4Sc%2BaNOgcWm_WJME2eRsQ@mail.gmail.com Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: <stable@vger.kernel.org> v3.4 --- arch/x86/kernel/ptrace.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 13b1990c7c5839..c4c6a5c2bf0f39 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -1211,12 +1211,6 @@ static long x32_arch_ptrace(struct task_struct *child, 0, sizeof(struct user_i387_struct), datap); - /* normal 64bit interface to access TLS data. - Works just like arch_prctl, except that the arguments - are reversed. */ - case PTRACE_ARCH_PRCTL: - return do_arch_prctl(child, data, addr); - default: return compat_ptrace_request(child, request, addr, data); } -- GitLab