All architecture use either:
nr = enter_from_user_mode_randomize_stack(regs, nr);
or
enter_from_user_mode_randomize_stack(regs);
nr = syscall_enter_from_user_mode_work(regs, nr);
Remove the now unused function.
Signed-off-by: Thomas Gleixner <[email protected]>
---
Documentation/core-api/entry.rst | 17 +++++++++-------
include/linux/entry-common.h | 40 +++------------------------------------
include/linux/irq-entry-common.h | 6 ++---
3 files changed, 17 insertions(+), 46 deletions(-)
--- a/Documentation/core-api/entry.rst
+++ b/Documentation/core-api/entry.rst
@@ -68,7 +68,7 @@ low-level C code must not be instrumente
noinstr void syscall(struct pt_regs *regs, int nr)
{
arch_syscall_enter(regs);
- nr = syscall_enter_from_user_mode(regs, nr);
+ nr = syscall_enter_from_user_mode_randomize_stack(regs, nr);
instrumentation_begin();
if (!invoke_syscall(regs, nr) && nr != -1)
@@ -78,12 +78,14 @@ low-level C code must not be instrumente
syscall_exit_to_user_mode(regs);
}
-syscall_enter_from_user_mode() first invokes enter_from_user_mode() which
-establishes state in the following order:
+syscall_enter_from_user_mode_randomize_stack() first invokes
+enter_from_user_mode_randomize_stack() which establishes state in the
+following order:
* Lockdep
* RCU / Context tracking
* Tracing
+ * Apply stack randomization
and then invokes the various entry work functions like ptrace, seccomp, audit,
syscall tracing, etc. After all that is done, the instrumentable invoke_syscall
@@ -99,10 +101,11 @@ that it invokes exit_to_user_mode() whic
* RCU / Context tracking
* Lockdep
-syscall_enter_from_user_mode() and syscall_exit_to_user_mode() are also
-available as fine grained subfunctions in cases where the architecture code
-has to do extra work between the various steps. In such cases it has to
-ensure that enter_from_user_mode() is called first on entry and
+syscall_enter_from_user_mode_randomize_stack() and
+syscall_exit_to_user_mode() are also available as fine grained subfunctions
+in cases where the architecture code has to do extra work between the
+various steps. In such cases it has to ensure that
+enter_from_user_mode_randomize_stack() is called first on entry and
exit_to_user_mode() is called last on exit.
Do not nest syscalls. Nested syscalls will cause RCU and/or context tracking
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@ -19,7 +19,7 @@
#endif
/*
- * SYSCALL_WORK flags handled in syscall_enter_from_user_mode()
+ * SYSCALL_WORK flags handled in syscall_enter_from_user_mode_work()
*/
#define SYSCALL_WORK_ENTER (SYSCALL_WORK_SECCOMP | \
SYSCALL_WORK_SYSCALL_TRACEPOINT | \
@@ -205,42 +205,10 @@ do {
\
_ret; \
})
-/**
- * syscall_enter_from_user_mode - Establish state and check and handle work
- * before invoking a syscall
- * @regs: Pointer to currents pt_regs
- * @syscall: The syscall number
- *
- * Invoked from architecture specific syscall entry code with interrupts
- * disabled. The calling code has to be non-instrumentable. When the
- * function returns all state is correct, interrupts are enabled and the
- * subsequent functions can be instrumented.
- *
- * This is the combination of enter_from_user_mode() and
- * syscall_enter_from_user_mode_work() to be used when there is no
- * architecture specific work to be done between the two.
- *
- * Returns: The original or a modified syscall number. See
- * syscall_enter_from_user_mode_work() for further explanation.
- */
-static __always_inline long syscall_enter_from_user_mode(struct pt_regs *regs,
long syscall)
-{
- long ret;
-
- enter_from_user_mode(regs);
-
- instrumentation_begin();
- local_irq_enable();
- ret = syscall_enter_from_user_mode_work(regs, syscall);
- instrumentation_end();
-
- return ret;
-}
-
/*
- * If SYSCALL_EMU is set, then the only reason to report is when
- * SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall
- * instruction has been already reported in syscall_enter_from_user_mode().
+ * If SYSCALL_EMU is set, then the only reason to report is when SINGLESTEP is
+ * set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall instruction has been
+ * already reported in syscall_enter_from_user_mode_work().
*/
static __always_inline bool report_single_step(unsigned long work)
{
--- a/include/linux/irq-entry-common.h
+++ b/include/linux/irq-entry-common.h
@@ -49,9 +49,9 @@
* Defaults to an empty implementation. Can be replaced by architecture
* specific code.
*
- * Invoked from syscall_enter_from_user_mode() in the non-instrumentable
- * section. Use __always_inline so the compiler cannot push it out of line
- * and make it instrumentable.
+ * Invoked from enter_from_user_mode_syscall_and_randomize_stack() in the
+ * non-instrumentable section. Use __always_inline so the compiler cannot push
+ * it out of line and make it instrumentable.
*/
static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs);
