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authorNadav Amit <namit@vmware.com>2019-04-27 02:22:44 +0300
committerIngo Molnar <mingo@kernel.org>2019-04-30 13:37:51 +0300
commitaad42dd44db086c79ca3f470ad563d2ac4ac218d (patch)
tree97e18c5ce8c7c12c3e026d1b481a0cbd6f361bf6
parentd97080ebed7811a53c931032a284166ee46b9565 (diff)
downloadlinux-aad42dd44db086c79ca3f470ad563d2ac4ac218d.tar.xz
uprobes: Initialize uprobes earlier
In order to have a separate address space for text poking, we need to duplicate init_mm early during start_kernel(). This, however, introduces a problem since uprobes functions are called from dup_mmap(), but uprobes is still not initialized in this early stage. Since uprobes initialization is necassary for fork, and since all the dependant initialization has been done when fork is initialized (percpu and vmalloc), move uprobes initialization to fork_init(). It does not seem uprobes introduces any security problem for the poking_mm. Crash and burn if uprobes initialization fails, similarly to other early initializations. Change the init_probes() name to probes_init() to match other early initialization functions name convention. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: ard.biesheuvel@linaro.org Cc: deneen.t.dock@intel.com Cc: kernel-hardening@lists.openwall.com Cc: kristen@linux.intel.com Cc: linux_dti@icloud.com Cc: will.deacon@arm.com Link: https://lkml.kernel.org/r/20190426232303.28381-6-nadav.amit@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--include/linux/uprobes.h5
-rw-r--r--kernel/events/uprobes.c8
-rw-r--r--kernel/fork.c1
3 files changed, 9 insertions, 5 deletions
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 103a48a48872..12bf0b68ed92 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -115,6 +115,7 @@ struct uprobes_state {
struct xol_area *xol_area;
};
+extern void __init uprobes_init(void);
extern int set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
extern int set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
extern bool is_swbp_insn(uprobe_opcode_t *insn);
@@ -154,6 +155,10 @@ extern void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
struct uprobes_state {
};
+static inline void uprobes_init(void)
+{
+}
+
#define uprobe_get_trap_addr(regs) instruction_pointer(regs)
static inline int
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index c5cde87329c7..e6a0d6be87e3 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -2294,16 +2294,14 @@ static struct notifier_block uprobe_exception_nb = {
.priority = INT_MAX-1, /* notified after kprobes, kgdb */
};
-static int __init init_uprobes(void)
+void __init uprobes_init(void)
{
int i;
for (i = 0; i < UPROBES_HASH_SZ; i++)
mutex_init(&uprobes_mmap_mutex[i]);
- if (percpu_init_rwsem(&dup_mmap_sem))
- return -ENOMEM;
+ BUG_ON(percpu_init_rwsem(&dup_mmap_sem));
- return register_die_notifier(&uprobe_exception_nb);
+ BUG_ON(register_die_notifier(&uprobe_exception_nb));
}
-__initcall(init_uprobes);
diff --git a/kernel/fork.c b/kernel/fork.c
index 9dcd18aa210b..44fba5e5e916 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -815,6 +815,7 @@ void __init fork_init(void)
#endif
lockdep_init_task(&init_task);
+ uprobes_init();
}
int __weak arch_dup_task_struct(struct task_struct *dst,