Am Mon, 22 Apr 2024 15:54:27 GMT Mark Johnston <ma...@freebsd.org> schrieb:
> The branch main has been updated by markj: > > URL: > https://cgit.FreeBSD.org/src/commit/?id=800da341bc4a35f4b4d82d104b130825d9a42ffa > > commit 800da341bc4a35f4b4d82d104b130825d9a42ffa > Author: Mark Johnston <ma...@freebsd.org> > AuthorDate: 2024-04-22 15:43:17 +0000 > Commit: Mark Johnston <ma...@freebsd.org> > CommitDate: 2024-04-22 15:46:59 +0000 > > thread: Simplify sanitizer integration with thread creation > > fork() may allocate a new thread in one of two ways: from UMA, or cached > in a freed proc that was just allocated from UMA. In either case, KASAN > and KMSAN need to initialize some state; in particular they need to > initialize the shadow mapping of the new thread's stack. > > This is done differently between KASAN and KMSAN, which is confusing. > This patch improves things a bit: > - Add a new thread_recycle() function, which moves all kernel stack > handling out of kern_fork.c, since it doesn't really belong there. > - Then, thread_alloc_stack() has only one local caller, so just inline > it. > - Avoid redundant shadow stack initialization: thread_alloc() > initializes the KMSAN shadow stack (via kmsan_thread_alloc()) even > through vm_thread_new() already did that. > - Add kasan_thread_alloc(), for consistency with kmsan_thread_alloc(). > > No functional change intended. > > Reviewed by: khng > MFC after: 1 week > Differential Revision: https://reviews.freebsd.org/D44891 > --- > sys/kern/kern_fork.c | 17 +++-------------- > sys/kern/kern_thread.c | 20 ++++++++++++-------- > sys/kern/subr_asan.c | 10 ++++++++++ > sys/sys/asan.h | 4 ++++ > sys/sys/proc.h | 2 +- > sys/vm/vm_glue.c | 9 ++++----- > 6 files changed, 34 insertions(+), 28 deletions(-) > > diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c > index d0044dfc19a0..41f6a76c4fa1 100644 > --- a/sys/kern/kern_fork.c > +++ b/sys/kern/kern_fork.c > @@ -40,7 +40,6 @@ > > #include <sys/param.h> > #include <sys/systm.h> > -#include <sys/asan.h> > #include <sys/bitstring.h> > #include <sys/sysproto.h> > #include <sys/eventhandler.h> > @@ -1019,19 +1018,9 @@ fork1(struct thread *td, struct fork_req *fr) > } > proc_linkup(newproc, td2); > } else { > - kmsan_thread_alloc(td2); > - if (td2->td_kstack == 0 || td2->td_kstack_pages != pages) { > - if (td2->td_kstack != 0) > - vm_thread_dispose(td2); > - if (!thread_alloc_stack(td2, pages)) { > - error = ENOMEM; > - goto fail2; > - } > - } else { > - kasan_mark((void *)td2->td_kstack, > - ptoa(td2->td_kstack_pages), > - ptoa(td2->td_kstack_pages), 0); > - } > + error = thread_recycle(td2, pages); > + if (error != 0) > + goto fail2; > } > > if ((flags & RFMEM) == 0) { > diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c > index 0bcd5c2f2add..725791769ac3 100644 > --- a/sys/kern/kern_thread.c > +++ b/sys/kern/kern_thread.c > @@ -798,6 +798,7 @@ thread_alloc(int pages) > } > td->td_tid = tid; > bzero(&td->td_sa.args, sizeof(td->td_sa.args)); > + kasan_thread_alloc(td); > kmsan_thread_alloc(td); > cpu_thread_alloc(td); > EVENTHANDLER_DIRECT_INVOKE(thread_ctor, td); > @@ -805,15 +806,18 @@ thread_alloc(int pages) > } > > int > -thread_alloc_stack(struct thread *td, int pages) > +thread_recycle(struct thread *td, int pages) > { > - > - KASSERT(td->td_kstack == 0, > - ("thread_alloc_stack called on a thread with kstack")); > - if (!vm_thread_new(td, pages)) > - return (0); > - cpu_thread_alloc(td); > - return (1); > + if (td->td_kstack == 0 || td->td_kstack_pages != pages) { > + if (td->td_kstack != 0) > + vm_thread_dispose(td); > + if (!vm_thread_new(td, pages)) > + return (ENOMEM); > + cpu_thread_alloc(td); > + } > + kasan_thread_alloc(td); > + kmsan_thread_alloc(td); > + return (0); > } > > /* > diff --git a/sys/kern/subr_asan.c b/sys/kern/subr_asan.c > index c3664d9cf6c2..75d9e75c531a 100644 > --- a/sys/kern/subr_asan.c > +++ b/sys/kern/subr_asan.c > @@ -39,6 +39,7 @@ __KERNEL_RCSID(0, "$NetBSD: subr_asan.c,v 1.26 2020/09/10 > 14:10:46 maxv > Exp $"); #include <sys/systm.h> > #include <sys/asan.h> > #include <sys/kernel.h> > +#include <sys/proc.h> > #include <sys/stack.h> > #include <sys/sysctl.h> > > @@ -294,6 +295,15 @@ kasan_mark(const void *addr, size_t size, size_t > redzsize, uint8_t code) > } > } > > +void > +kasan_thread_alloc(struct thread *td) > +{ > + if (td->td_kstack != 0) { > + kasan_mark((void *)td->td_kstack, ptoa(td->td_kstack_pages), > + ptoa(td->td_kstack_pages), 0); > + } > +} > + > /* > -------------------------------------------------------------------------- */ > > #define ADDR_CROSSES_SCALE_BOUNDARY(addr, size) \ > diff --git a/sys/sys/asan.h b/sys/sys/asan.h > index a3becdef5f57..6a01d0531725 100644 > --- a/sys/sys/asan.h > +++ b/sys/sys/asan.h > @@ -53,14 +53,18 @@ > #define KASAN_KSTACK_FREED 0xFE > #define KASAN_EXEC_ARGS_FREED 0xFF > > +struct thread; > + > void kasan_init(void); > void kasan_init_early(vm_offset_t, size_t); > void kasan_shadow_map(vm_offset_t, size_t); > void kasan_mark(const void *, size_t, size_t, uint8_t); > +void kasan_thread_alloc(struct thread *); > #else /* KASAN */ > #define kasan_init() > #define kasan_shadow_map(a, s) > #define kasan_mark(p, s, l, c) > +#define kasan_thread_alloc(t) > #endif /* !KASAN */ > > #endif /* !_SYS_ASAN_H_ */ > diff --git a/sys/sys/proc.h b/sys/sys/proc.h > index 33b836f4150e..1b542d1374b4 100644 > --- a/sys/sys/proc.h > +++ b/sys/sys/proc.h > @@ -1262,7 +1262,6 @@ void cpu_thread_free(struct thread *); > void cpu_thread_swapin(struct thread *); > void cpu_thread_swapout(struct thread *); > struct thread *thread_alloc(int pages); > -int thread_alloc_stack(struct thread *, int pages); > int thread_check_susp(struct thread *td, bool sleep); > void thread_cow_get_proc(struct thread *newtd, struct proc *p); > void thread_cow_get(struct thread *newtd, struct thread *td); > @@ -1275,6 +1274,7 @@ void thread_exit(void) __dead2; > void thread_free(struct thread *td); > void thread_link(struct thread *td, struct proc *p); > void thread_reap_barrier(void); > +int thread_recycle(struct thread *, int pages); > int thread_single(struct proc *p, int how); > void thread_single_end(struct proc *p, int how); > void thread_stash(struct thread *td); > diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c > index 4292a7533503..f9235fe03fab 100644 > --- a/sys/vm/vm_glue.c > +++ b/sys/vm/vm_glue.c > @@ -543,8 +543,6 @@ vm_thread_new(struct thread *td, int pages) > td->td_kstack = ks; > td->td_kstack_pages = pages; > td->td_kstack_domain = ks_domain; > - kasan_mark((void *)ks, ptoa(pages), ptoa(pages), 0); > - kmsan_mark((void *)ks, ptoa(pages), KMSAN_STATE_UNINIT); > return (1); > } > > @@ -562,11 +560,12 @@ vm_thread_dispose(struct thread *td) > td->td_kstack = 0; > td->td_kstack_pages = 0; > td->td_kstack_domain = MAXMEMDOM; > - kasan_mark((void *)ks, 0, ptoa(pages), KASAN_KSTACK_FREED); > - if (pages == kstack_pages) > + if (pages == kstack_pages) { > + kasan_mark((void *)ks, 0, ptoa(pages), KASAN_KSTACK_FREED); > uma_zfree(kstack_cache, (void *)ks); > - else > + } else { > vm_thread_stack_dispose(ks, pages); > + } > } > > /* > It seems to me that this commit breaks make buildkernel: [...] ===> accf_dns (all) --- kern_thread.o --- /usr/src/sys/kern/kern_thread.c:801:2: error: call to undeclared function 'kasan_thread_alloc'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration] 801 | kasan_thread_alloc(td); | ^ /usr/src/sys/kern/kern_thread.c:818:2: error: call to undeclared function 'kasan_thread_alloc'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration] --- modules-all --- --- all_subdir_accf_http --- ===> accf_http (all) --- kern_thread.o --- 818 | kasan_thread_alloc(td); | ^ 2 errors generated. Kind regards, oh -- O. Hartmann
