[PATCH 2/3] [RFC] seccomp: give BPF x32 bit when restoring x32 filter

Commit fca460f hpa(a)zytor.com 2012-02-19 07:56:26 -0800 x32: Handle the x32 system call flag provided a method to multiplex architecture with the syscall number for X32 calls. Commit 8b4b9f2 pmoore(a)redhat.com 2013-02-15 12:21:43 -0500 x86: remove the x32 syscall bitmask from syscall_get_nr() broke audit and potentially other users of syscall_get_nr() which depend on that call as named. Commit audit: add AUDIT_ARCH_X86_X32 arch definition is required to provide the new ARCH definition AUDIT_ARCH_X86_X32 for syscall_get_arch(). This patch along with reverting 8b4b9f2 should satisfy other regular users of syscall_get_nr() without changing the seccomp interface to BPF. Cc: Paul Moore <pmoore(a)redhat.com&gt; Cc: Eric Paris <eparis(a)redhat.com&gt; Cc: Al Viro <aviro(a)redhat.com&gt; Cc: Will Drewry <wad(a)chromium.org&gt; Cc: H. Peter Anvin <hpa(a)zytor.com&gt; Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; Link: http://lkml.kernel.org/r/cover.1405023592.git.rgb@redhat.com --- arch/x86/include/asm/syscall.h | 4 ++++ kernel/seccomp.c | 6 ++++++ 2 files changed, 10 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h index d6a756a..d58b6be 100644 --- a/arch/x86/include/asm/syscall.h +++ b/arch/x86/include/asm/syscall.h @@ -236,6 +236,10 @@ static inline int syscall_get_arch(void) return AUDIT_ARCH_I386; #endif /* Both x32 and x86_64 are considered "64-bit". */ +#ifdef CONFIG_X86_X32_ABI + if (task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT) + return AUDIT_ARCH_X86_X32; +#endif return AUDIT_ARCH_X86_64; } #endif /* CONFIG_X86_32 */ diff --git a/kernel/seccomp.c b/kernel/seccomp.c index b35c215..bc18214 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -73,6 +73,12 @@ static void populate_seccomp_data(struct seccomp_data *sd) sd->nr = syscall_get_nr(task, regs); sd->arch = syscall_get_arch(); +#ifdef CONFIG_X86_X32_ABI + if (sd->arch == AUDIT_ARCH_X86_X32) { + sd->arch = AUDIT_ARCH_X86_64; + sd->nr |= __X32_SYSCALL_BIT; + } +#endif syscall_get_arguments(task, regs, 0, 6, args); sd->args[0] = args[0]; sd->args[1] = args[1]; -- 1.7.1