Merge tag 'core-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

torvalds · torvalds · commit e99b2507bacc · 2020-08-23T11:05:47.000-07:00
Pull entry fix from Thomas Gleixner:
 "A single bug fix for the common entry code.

  The transcription of the x86 version messed up the reload of the
  syscall number from pt_regs after ptrace and seccomp which breaks
  syscall number rewriting"

* tag 'core-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  core/entry: Respect syscall number rewrites
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
@@ -65,7 +65,8 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,
 
 	syscall_enter_audit(regs, syscall);
 
-	return ret ? : syscall;
+	/* The above might have changed the syscall number */
+	return ret ? : syscall_get_nr(current, regs);
 }
 
 noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall)

Original file line number	Diff line number	Diff line change
`@@ -65,7 +65,8 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,`
`65`	`65`
`66`	`66`	`syscall_enter_audit(regs, syscall);`
`67`	`67`
`68`		`- return ret ? : syscall;`
	`68`	`+ /* The above might have changed the syscall number */`
	`69`	`+ return ret ? : syscall_get_nr(current, regs);`
`69`	`70`	`}`
`70`	`71`
`71`	`72`	`noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall)`