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authorAndy Lutomirski <luto@kernel.org>2015-07-03 22:44:23 +0300
committerIngo Molnar <mingo@kernel.org>2015-07-07 11:59:05 +0300
commit1f484aa6904697f390027c12fba130fa94b20831 (patch)
treed5e343cf9aa47081df111232e0d07074b00bd903 /arch/x86/kernel/ptrace.c
parente727c7d7a11e109849582e9165d54b254eb181d7 (diff)
downloadlinux-1f484aa6904697f390027c12fba130fa94b20831.tar.xz
x86/entry: Move C entry and exit code to arch/x86/entry/common.c
The entry and exit C helpers were confusingly scattered between ptrace.c and signal.c, even though they aren't specific to ptrace or signal handling. Move them together in a new file. This change just moves code around. It doesn't change anything. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/324d686821266544d8572423cc281f961da445f4.1435952415.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/ptrace.c')
-rw-r--r--arch/x86/kernel/ptrace.c202
1 files changed, 1 insertions, 201 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 7155957b3c25..558f50edebca 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -37,12 +37,10 @@
#include <asm/proto.h>
#include <asm/hw_breakpoint.h>
#include <asm/traps.h>
+#include <asm/syscall.h>
#include "tls.h"
-#define CREATE_TRACE_POINTS
-#include <trace/events/syscalls.h>
-
enum x86_regset {
REGSET_GENERAL,
REGSET_FP,
@@ -1444,201 +1442,3 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
/* Send us the fake SIGTRAP */
force_sig_info(SIGTRAP, &info, tsk);
}
-
-static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch)
-{
-#ifdef CONFIG_X86_64
- if (arch == AUDIT_ARCH_X86_64) {
- audit_syscall_entry(regs->orig_ax, regs->di,
- regs->si, regs->dx, regs->r10);
- } else
-#endif
- {
- audit_syscall_entry(regs->orig_ax, regs->bx,
- regs->cx, regs->dx, regs->si);
- }
-}
-
-/*
- * We can return 0 to resume the syscall or anything else to go to phase
- * 2. If we resume the syscall, we need to put something appropriate in
- * regs->orig_ax.
- *
- * NB: We don't have full pt_regs here, but regs->orig_ax and regs->ax
- * are fully functional.
- *
- * For phase 2's benefit, our return value is:
- * 0: resume the syscall
- * 1: go to phase 2; no seccomp phase 2 needed
- * anything else: go to phase 2; pass return value to seccomp
- */
-unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch)
-{
- unsigned long ret = 0;
- u32 work;
-
- BUG_ON(regs != task_pt_regs(current));
-
- work = ACCESS_ONCE(current_thread_info()->flags) &
- _TIF_WORK_SYSCALL_ENTRY;
-
- /*
- * If TIF_NOHZ is set, we are required to call user_exit() before
- * doing anything that could touch RCU.
- */
- if (work & _TIF_NOHZ) {
- user_exit();
- work &= ~_TIF_NOHZ;
- }
-
-#ifdef CONFIG_SECCOMP
- /*
- * Do seccomp first -- it should minimize exposure of other
- * code, and keeping seccomp fast is probably more valuable
- * than the rest of this.
- */
- if (work & _TIF_SECCOMP) {
- struct seccomp_data sd;
-
- sd.arch = arch;
- sd.nr = regs->orig_ax;
- sd.instruction_pointer = regs->ip;
-#ifdef CONFIG_X86_64
- if (arch == AUDIT_ARCH_X86_64) {
- sd.args[0] = regs->di;
- sd.args[1] = regs->si;
- sd.args[2] = regs->dx;
- sd.args[3] = regs->r10;
- sd.args[4] = regs->r8;
- sd.args[5] = regs->r9;
- } else
-#endif
- {
- sd.args[0] = regs->bx;
- sd.args[1] = regs->cx;
- sd.args[2] = regs->dx;
- sd.args[3] = regs->si;
- sd.args[4] = regs->di;
- sd.args[5] = regs->bp;
- }
-
- BUILD_BUG_ON(SECCOMP_PHASE1_OK != 0);
- BUILD_BUG_ON(SECCOMP_PHASE1_SKIP != 1);
-
- ret = seccomp_phase1(&sd);
- if (ret == SECCOMP_PHASE1_SKIP) {
- regs->orig_ax = -1;
- ret = 0;
- } else if (ret != SECCOMP_PHASE1_OK) {
- return ret; /* Go directly to phase 2 */
- }
-
- work &= ~_TIF_SECCOMP;
- }
-#endif
-
- /* Do our best to finish without phase 2. */
- if (work == 0)
- return ret; /* seccomp and/or nohz only (ret == 0 here) */
-
-#ifdef CONFIG_AUDITSYSCALL
- if (work == _TIF_SYSCALL_AUDIT) {
- /*
- * If there is no more work to be done except auditing,
- * then audit in phase 1. Phase 2 always audits, so, if
- * we audit here, then we can't go on to phase 2.
- */
- do_audit_syscall_entry(regs, arch);
- return 0;
- }
-#endif
-
- return 1; /* Something is enabled that we can't handle in phase 1 */
-}
-
-/* Returns the syscall nr to run (which should match regs->orig_ax). */
-long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch,
- unsigned long phase1_result)
-{
- long ret = 0;
- u32 work = ACCESS_ONCE(current_thread_info()->flags) &
- _TIF_WORK_SYSCALL_ENTRY;
-
- BUG_ON(regs != task_pt_regs(current));
-
- /*
- * If we stepped into a sysenter/syscall insn, it trapped in
- * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
- * If user-mode had set TF itself, then it's still clear from
- * do_debug() and we need to set it again to restore the user
- * state. If we entered on the slow path, TF was already set.
- */
- if (work & _TIF_SINGLESTEP)
- regs->flags |= X86_EFLAGS_TF;
-
-#ifdef CONFIG_SECCOMP
- /*
- * Call seccomp_phase2 before running the other hooks so that
- * they can see any changes made by a seccomp tracer.
- */
- if (phase1_result > 1 && seccomp_phase2(phase1_result)) {
- /* seccomp failures shouldn't expose any additional code. */
- return -1;
- }
-#endif
-
- if (unlikely(work & _TIF_SYSCALL_EMU))
- ret = -1L;
-
- if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
- tracehook_report_syscall_entry(regs))
- ret = -1L;
-
- if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
- trace_sys_enter(regs, regs->orig_ax);
-
- do_audit_syscall_entry(regs, arch);
-
- return ret ?: regs->orig_ax;
-}
-
-long syscall_trace_enter(struct pt_regs *regs)
-{
- u32 arch = is_ia32_task() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
- unsigned long phase1_result = syscall_trace_enter_phase1(regs, arch);
-
- if (phase1_result == 0)
- return regs->orig_ax;
- else
- return syscall_trace_enter_phase2(regs, arch, phase1_result);
-}
-
-void syscall_trace_leave(struct pt_regs *regs)
-{
- bool step;
-
- /*
- * We may come here right after calling schedule_user()
- * or do_notify_resume(), in which case we can be in RCU
- * user mode.
- */
- user_exit();
-
- audit_syscall_exit(regs);
-
- if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
- trace_sys_exit(regs, regs->ax);
-
- /*
- * If TIF_SYSCALL_EMU is set, we only get here because of
- * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
- * We already reported this syscall instruction in
- * syscall_trace_enter().
- */
- step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
- !test_thread_flag(TIF_SYSCALL_EMU);
- if (step || test_thread_flag(TIF_SYSCALL_TRACE))
- tracehook_report_syscall_exit(regs, step);
-
- user_enter();
-}