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x86/entry: Consolidate check_user_regs()

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The user register sanity check is sprinkled all over the place. Move it
into enter_from_user_mode().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200722220519.943016204@linutronix.de
This commit is contained in:
Thomas Gleixner 2020-07-23 00:00:00 +02:00
parent b35ad8405d
commit 8d5ea35c5e
1 changed files with 9 additions and 15 deletions
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24
arch/x86/entry/common.c
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@ -82,10 +82,11 @@ static noinstr void check_user_regs(struct pt_regs *regs)
* 2) Invoke context tracking if enabled to reactivate RCU
* 3) Trace interrupts off state
*/
static noinstr void enter_from_user_mode(void)
static noinstr void enter_from_user_mode(struct pt_regs *regs)
{
enum ctx_state state = ct_state();
check_user_regs(regs);
lockdep_hardirqs_off(CALLER_ADDR0);
user_exit_irqoff();
@ -95,8 +96,9 @@ static noinstr void enter_from_user_mode(void)
instrumentation_end();
}
#else
static __always_inline void enter_from_user_mode(void)
static __always_inline void enter_from_user_mode(struct pt_regs *regs)
{
check_user_regs(regs);
lockdep_hardirqs_off(CALLER_ADDR0);
instrumentation_begin();
trace_hardirqs_off_finish();
@ -369,9 +371,7 @@ __visible noinstr void do_syscall_64(unsigned long nr, struct pt_regs *regs)
{
struct thread_info *ti;
check_user_regs(regs);
enter_from_user_mode();
enter_from_user_mode(regs);
instrumentation_begin();
local_irq_enable();
@ -434,9 +434,7 @@ static void do_syscall_32_irqs_on(struct pt_regs *regs)
/* Handles int $0x80 */
__visible noinstr void do_int80_syscall_32(struct pt_regs *regs)
{
check_user_regs(regs);
enter_from_user_mode();
enter_from_user_mode(regs);
instrumentation_begin();
local_irq_enable();
@ -487,8 +485,6 @@ __visible noinstr long do_fast_syscall_32(struct pt_regs *regs)
vdso_image_32.sym_int80_landing_pad;
bool success;
check_user_regs(regs);
/*
* SYSENTER loses EIP, and even SYSCALL32 needs us to skip forward
* so that 'regs->ip -= 2' lands back on an int $0x80 instruction.
@ -496,7 +492,7 @@ __visible noinstr long do_fast_syscall_32(struct pt_regs *regs)
*/
regs->ip = landing_pad;
enter_from_user_mode();
enter_from_user_mode(regs);
instrumentation_begin();
local_irq_enable();
@ -599,8 +595,7 @@ idtentry_state_t noinstr idtentry_enter(struct pt_regs *regs)
};
if (user_mode(regs)) {
check_user_regs(regs);
enter_from_user_mode();
enter_from_user_mode(regs);
return ret;
}
@ -733,8 +728,7 @@ void noinstr idtentry_exit(struct pt_regs *regs, idtentry_state_t state)
*/
void noinstr idtentry_enter_user(struct pt_regs *regs)
{
check_user_regs(regs);
enter_from_user_mode();
enter_from_user_mode(regs);
}
/**