Merge tag 'v5.9-rc4' into patchwork

Linux 5.9-rc4

* tag 'v5.9-rc4': (1001 commits)
  Linux 5.9-rc4
  io_uring: fix linked deferred ->files cancellation
  io_uring: fix cancel of deferred reqs with ->files
  include/linux/log2.h: add missing () around n in roundup_pow_of_two()
  mm/khugepaged.c: fix khugepaged's request size in collapse_file
  mm/hugetlb: fix a race between hugetlb sysctl handlers
  mm/hugetlb: try preferred node first when alloc gigantic page from cma
  mm/migrate: preserve soft dirty in remove_migration_pte()
  mm/migrate: remove unnecessary is_zone_device_page() check
  mm/rmap: fixup copying of soft dirty and uffd ptes
  mm/migrate: fixup setting UFFD_WP flag
  mm: madvise: fix vma user-after-free
  checkpatch: fix the usage of capture group ( ... )
  fork: adjust sysctl_max_threads definition to match prototype
  ipc: adjust proc_ipc_sem_dointvec definition to match prototype
  mm: track page table modifications in __apply_to_page_range()
  MAINTAINERS: IA64: mark Status as Odd Fixes only
  MAINTAINERS: add LLVM maintainers
  MAINTAINERS: update Cavium/Marvell entries
  mm: slub: fix conversion of freelist_corrupted()
  ...

1 files changed, 20 insertions, 9 deletions

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 48512c7944e7..2f84c7ca74ea 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -60,16 +60,10 @@ __visible noinstr void do_syscall_64(unsigned long nr, struct pt_regs *regs)
 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
 static __always_inline unsigned int syscall_32_enter(struct pt_regs *regs)
 {
-	unsigned int nr = (unsigned int)regs->orig_ax;
-
 	if (IS_ENABLED(CONFIG_IA32_EMULATION))
 		current_thread_info()->status |= TS_COMPAT;
-	/*
-	 * Subtlety here: if ptrace pokes something larger than 2^32-1 into
-	 * orig_ax, the unsigned int return value truncates it.  This may
-	 * or may not be necessary, but it matches the old asm behavior.
-	 */
-	return (unsigned int)syscall_enter_from_user_mode(regs, nr);
+
+	return (unsigned int)regs->orig_ax;
 }
 
 /*
@@ -91,15 +85,29 @@ __visible noinstr void do_int80_syscall_32(struct pt_regs *regs)
 {
 	unsigned int nr = syscall_32_enter(regs);
 
+	/*
+	 * Subtlety here: if ptrace pokes something larger than 2^32-1 into
+	 * orig_ax, the unsigned int return value truncates it.  This may
+	 * or may not be necessary, but it matches the old asm behavior.
+	 */
+	nr = (unsigned int)syscall_enter_from_user_mode(regs, nr);
+
 	do_syscall_32_irqs_on(regs, nr);
 	syscall_exit_to_user_mode(regs);
 }
 
 static noinstr bool __do_fast_syscall_32(struct pt_regs *regs)
 {
-	unsigned int nr	= syscall_32_enter(regs);
+	unsigned int nr = syscall_32_enter(regs);
 	int res;
 
+	/*
+	 * This cannot use syscall_enter_from_user_mode() as it has to
+	 * fetch EBP before invoking any of the syscall entry work
+	 * functions.
+	 */
+	syscall_enter_from_user_mode_prepare(regs);
+
 	instrumentation_begin();
 	/* Fetch EBP from where the vDSO stashed it. */
 	if (IS_ENABLED(CONFIG_X86_64)) {
@@ -122,6 +130,9 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs)
 		return false;
 	}
 
+	/* The case truncates any ptrace induced syscall nr > 2^32 -1 */
+	nr = (unsigned int)syscall_enter_from_user_mode_work(regs, nr);
+
 	/* Now this is just like a normal syscall. */
 	do_syscall_32_irqs_on(regs, nr);
 	syscall_exit_to_user_mode(regs);