| Message ID | 20240322060947.3254967-2-tujinjiang@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/ksm: fix ksm exec support for prctl | expand |
On 22.03.24 07:09, Jinjiang Tu wrote: > commit 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") inherits > MMF_VM_MERGE_ANY flag when a task calls execve(). Howerver, it doesn't > create the mm_slot, so ksmd will not try to scan this task. > > To fix it, allocate and add the mm_slot to ksm_mm_head in __bprm_mm_init() > when the mm has MMF_VM_MERGE_ANY flag. > > Fixes: 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") > Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> > --- > fs/exec.c | 10 ++++++++++ > include/linux/ksm.h | 13 +++++++++++++ > 2 files changed, 23 insertions(+) > > diff --git a/fs/exec.c b/fs/exec.c > index ff6f26671cfc..66202d016a0a 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -67,6 +67,7 @@ > #include <linux/time_namespace.h> > #include <linux/user_events.h> > #include <linux/rseq.h> > +#include <linux/ksm.h> > > #include <linux/uaccess.h> > #include <asm/mmu_context.h> > @@ -267,6 +268,13 @@ static int __bprm_mm_init(struct linux_binprm *bprm) > goto err_free; > } > > + /* > + * Need to be called with mmap write lock > + * held, to avoid race with ksmd. > + */ > + if (ksm_execve(mm)) > + goto err_ksm; > + But now, would we revert what insert_vm_struct() did? We're freeing the VMA later, but we might have accounted memory. What would be cleaner is doing the ksm_execve() before the insert_vm_struct(), and then cleaning up in case insert_vm_struct() failed.
Hi Jinjiang,
kernel test robot noticed the following build warnings:
[auto build test WARNING on akpm-mm/mm-everything]
url: https://github.com/intel-lab-lkp/linux/commits/Jinjiang-Tu/mm-ksm-fix-ksm-exec-support-for-prctl/20240322-141317
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20240322060947.3254967-2-tujinjiang%40huawei.com
patch subject: [PATCH v2 1/2] mm/ksm: fix ksm exec support for prctl
config: s390-allnoconfig (https://download.01.org/0day-ci/archive/20240324/202403240716.8B7CiDbr-lkp@intel.com/config)
compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project 23de3862dce582ce91c1aa914467d982cb1a73b4)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240324/202403240716.8B7CiDbr-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202403240716.8B7CiDbr-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from fs/exec.c:30:
In file included from include/linux/mm.h:2211:
include/linux/vmstat.h:514:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
514 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
| ~~~~~~~~~~~ ^ ~~~
>> fs/exec.c:275:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
275 | if (ksm_execve(mm))
| ^~~~~~~~~~~~~~
fs/exec.c:305:9: note: uninitialized use occurs here
305 | return err;
| ^~~
fs/exec.c:275:2: note: remove the 'if' if its condition is always false
275 | if (ksm_execve(mm))
| ^~~~~~~~~~~~~~~~~~~
276 | goto err_ksm;
| ~~~~~~~~~~~~
fs/exec.c:257:9: note: initialize the variable 'err' to silence this warning
257 | int err;
| ^
| = 0
2 warnings generated.
vim +275 fs/exec.c
254
255 static int __bprm_mm_init(struct linux_binprm *bprm)
256 {
257 int err;
258 struct vm_area_struct *vma = NULL;
259 struct mm_struct *mm = bprm->mm;
260
261 bprm->vma = vma = vm_area_alloc(mm);
262 if (!vma)
263 return -ENOMEM;
264 vma_set_anonymous(vma);
265
266 if (mmap_write_lock_killable(mm)) {
267 err = -EINTR;
268 goto err_free;
269 }
270
271 /*
272 * Need to be called with mmap write lock
273 * held, to avoid race with ksmd.
274 */
> 275 if (ksm_execve(mm))
276 goto err_ksm;
277
278 /*
279 * Place the stack at the largest stack address the architecture
280 * supports. Later, we'll move this to an appropriate place. We don't
281 * use STACK_TOP because that can depend on attributes which aren't
282 * configured yet.
283 */
284 BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP);
285 vma->vm_end = STACK_TOP_MAX;
286 vma->vm_start = vma->vm_end - PAGE_SIZE;
287 vm_flags_init(vma, VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP);
288 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
289
290 err = insert_vm_struct(mm, vma);
291 if (err)
292 goto err;
293
294 mm->stack_vm = mm->total_vm = 1;
295 mmap_write_unlock(mm);
296 bprm->p = vma->vm_end - sizeof(void *);
297 return 0;
298 err:
299 ksm_exit(mm);
300 err_ksm:
301 mmap_write_unlock(mm);
302 err_free:
303 bprm->vma = NULL;
304 vm_area_free(vma);
305 return err;
306 }
307
在 2024/3/22 17:02, David Hildenbrand 写道: > On 22.03.24 07:09, Jinjiang Tu wrote: >> commit 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") inherits >> MMF_VM_MERGE_ANY flag when a task calls execve(). Howerver, it doesn't >> create the mm_slot, so ksmd will not try to scan this task. >> >> To fix it, allocate and add the mm_slot to ksm_mm_head in >> __bprm_mm_init() >> when the mm has MMF_VM_MERGE_ANY flag. >> >> Fixes: 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") >> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> >> --- >> fs/exec.c | 10 ++++++++++ >> include/linux/ksm.h | 13 +++++++++++++ >> 2 files changed, 23 insertions(+) >> >> diff --git a/fs/exec.c b/fs/exec.c >> index ff6f26671cfc..66202d016a0a 100644 >> --- a/fs/exec.c >> +++ b/fs/exec.c >> @@ -67,6 +67,7 @@ >> #include <linux/time_namespace.h> >> #include <linux/user_events.h> >> #include <linux/rseq.h> >> +#include <linux/ksm.h> >> #include <linux/uaccess.h> >> #include <asm/mmu_context.h> >> @@ -267,6 +268,13 @@ static int __bprm_mm_init(struct linux_binprm >> *bprm) >> goto err_free; >> } >> + /* >> + * Need to be called with mmap write lock >> + * held, to avoid race with ksmd. >> + */ >> + if (ksm_execve(mm)) >> + goto err_ksm; >> + > > But now, would we revert what insert_vm_struct() did? > > We're freeing the VMA later, but we might have accounted memory. > > > What would be cleaner is doing the ksm_execve() before the > insert_vm_struct(), and then cleaning up in case insert_vm_struct() > failed. In fact, ksm_execve() has been called before the insert_vm_struct() in this patch.
Hi Jinjiang,
kernel test robot noticed the following build warnings:
url: https://github.com/intel-lab-lkp/linux/commits/Jinjiang-Tu/mm-ksm-fix-ksm-exec-support-for-prctl/20240322-141317
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20240322060947.3254967-2-tujinjiang%40huawei.com
patch subject: [PATCH v2 1/2] mm/ksm: fix ksm exec support for prctl
config: openrisc-randconfig-r081-20240322 (https://download.01.org/0day-ci/archive/20240324/202403240146.Pv4gVc5N-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 13.2.0
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202403240146.Pv4gVc5N-lkp@intel.com/
smatch warnings:
fs/exec.c:305 __bprm_mm_init() error: uninitialized symbol 'err'.
vim +/err +305 fs/exec.c
b6a2fea39318e43 Ollie Wild 2007-07-19 255 static int __bprm_mm_init(struct linux_binprm *bprm)
b6a2fea39318e43 Ollie Wild 2007-07-19 256 {
eaccbfa564e48c8 Luiz Fernando N. Capitulino 2009-01-06 257 int err;
b6a2fea39318e43 Ollie Wild 2007-07-19 258 struct vm_area_struct *vma = NULL;
b6a2fea39318e43 Ollie Wild 2007-07-19 259 struct mm_struct *mm = bprm->mm;
b6a2fea39318e43 Ollie Wild 2007-07-19 260
490fc053865c9cc Linus Torvalds 2018-07-21 261 bprm->vma = vma = vm_area_alloc(mm);
b6a2fea39318e43 Ollie Wild 2007-07-19 262 if (!vma)
eaccbfa564e48c8 Luiz Fernando N. Capitulino 2009-01-06 263 return -ENOMEM;
bfd40eaff5abb9f Kirill A. Shutemov 2018-07-26 264 vma_set_anonymous(vma);
b6a2fea39318e43 Ollie Wild 2007-07-19 265
d8ed45c5dcd455f Michel Lespinasse 2020-06-08 266 if (mmap_write_lock_killable(mm)) {
f268dfe905d4682 Michal Hocko 2016-05-23 267 err = -EINTR;
f268dfe905d4682 Michal Hocko 2016-05-23 268 goto err_free;
f268dfe905d4682 Michal Hocko 2016-05-23 269 }
b6a2fea39318e43 Ollie Wild 2007-07-19 270
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 271 /*
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 272 * Need to be called with mmap write lock
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 273 * held, to avoid race with ksmd.
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 274 */
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 275 if (ksm_execve(mm))
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 276 goto err_ksm;
"err" not set before the goto.
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 277
b6a2fea39318e43 Ollie Wild 2007-07-19 278 /*
b6a2fea39318e43 Ollie Wild 2007-07-19 279 * Place the stack at the largest stack address the architecture
b6a2fea39318e43 Ollie Wild 2007-07-19 280 * supports. Later, we'll move this to an appropriate place. We don't
b6a2fea39318e43 Ollie Wild 2007-07-19 281 * use STACK_TOP because that can depend on attributes which aren't
b6a2fea39318e43 Ollie Wild 2007-07-19 282 * configured yet.
b6a2fea39318e43 Ollie Wild 2007-07-19 283 */
aacb3d17a73f644 Michal Hocko 2011-07-26 284 BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP);
b6a2fea39318e43 Ollie Wild 2007-07-19 285 vma->vm_end = STACK_TOP_MAX;
b6a2fea39318e43 Ollie Wild 2007-07-19 286 vma->vm_start = vma->vm_end - PAGE_SIZE;
1c71222e5f2393b Suren Baghdasaryan 2023-01-26 287 vm_flags_init(vma, VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP);
3ed75eb8f1cd895 Coly Li 2007-10-18 288 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
462e635e5b73ba9 Tavis Ormandy 2010-12-09 289
b6a2fea39318e43 Ollie Wild 2007-07-19 290 err = insert_vm_struct(mm, vma);
eaccbfa564e48c8 Luiz Fernando N. Capitulino 2009-01-06 291 if (err)
b6a2fea39318e43 Ollie Wild 2007-07-19 292 goto err;
b6a2fea39318e43 Ollie Wild 2007-07-19 293
b6a2fea39318e43 Ollie Wild 2007-07-19 294 mm->stack_vm = mm->total_vm = 1;
d8ed45c5dcd455f Michel Lespinasse 2020-06-08 295 mmap_write_unlock(mm);
b6a2fea39318e43 Ollie Wild 2007-07-19 296 bprm->p = vma->vm_end - sizeof(void *);
b6a2fea39318e43 Ollie Wild 2007-07-19 297 return 0;
b6a2fea39318e43 Ollie Wild 2007-07-19 298 err:
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 299 ksm_exit(mm);
d282f6b19afd1a9 Jinjiang Tu 2024-03-22 300 err_ksm:
d8ed45c5dcd455f Michel Lespinasse 2020-06-08 301 mmap_write_unlock(mm);
f268dfe905d4682 Michal Hocko 2016-05-23 302 err_free:
b6a2fea39318e43 Ollie Wild 2007-07-19 303 bprm->vma = NULL;
3928d4f5ee37cdc Linus Torvalds 2018-07-21 304 vm_area_free(vma);
b6a2fea39318e43 Ollie Wild 2007-07-19 @305 return err;
b6a2fea39318e43 Ollie Wild 2007-07-19 306 }
在 2024/3/25 13:44, Dan Carpenter 写道: > Hi Jinjiang, > > kernel test robot noticed the following build warnings: > > url: https://github.com/intel-lab-lkp/linux/commits/Jinjiang-Tu/mm-ksm-fix-ksm-exec-support-for-prctl/20240322-141317 > base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything > patch link: https://lore.kernel.org/r/20240322060947.3254967-2-tujinjiang%40huawei.com > patch subject: [PATCH v2 1/2] mm/ksm: fix ksm exec support for prctl > config: openrisc-randconfig-r081-20240322 (https://download.01.org/0day-ci/archive/20240324/202403240146.Pv4gVc5N-lkp@intel.com/config) > compiler: or1k-linux-gcc (GCC) 13.2.0 > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <lkp@intel.com> > | Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > | Closes: https://lore.kernel.org/r/202403240146.Pv4gVc5N-lkp@intel.com/ > > smatch warnings: > fs/exec.c:305 __bprm_mm_init() error: uninitialized symbol 'err'. > > vim +/err +305 fs/exec.c > > b6a2fea39318e43 Ollie Wild 2007-07-19 255 static int __bprm_mm_init(struct linux_binprm *bprm) > b6a2fea39318e43 Ollie Wild 2007-07-19 256 { > eaccbfa564e48c8 Luiz Fernando N. Capitulino 2009-01-06 257 int err; > b6a2fea39318e43 Ollie Wild 2007-07-19 258 struct vm_area_struct *vma = NULL; > b6a2fea39318e43 Ollie Wild 2007-07-19 259 struct mm_struct *mm = bprm->mm; > b6a2fea39318e43 Ollie Wild 2007-07-19 260 > 490fc053865c9cc Linus Torvalds 2018-07-21 261 bprm->vma = vma = vm_area_alloc(mm); > b6a2fea39318e43 Ollie Wild 2007-07-19 262 if (!vma) > eaccbfa564e48c8 Luiz Fernando N. Capitulino 2009-01-06 263 return -ENOMEM; > bfd40eaff5abb9f Kirill A. Shutemov 2018-07-26 264 vma_set_anonymous(vma); > b6a2fea39318e43 Ollie Wild 2007-07-19 265 > d8ed45c5dcd455f Michel Lespinasse 2020-06-08 266 if (mmap_write_lock_killable(mm)) { > f268dfe905d4682 Michal Hocko 2016-05-23 267 err = -EINTR; > f268dfe905d4682 Michal Hocko 2016-05-23 268 goto err_free; > f268dfe905d4682 Michal Hocko 2016-05-23 269 } > b6a2fea39318e43 Ollie Wild 2007-07-19 270 > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 271 /* > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 272 * Need to be called with mmap write lock > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 273 * held, to avoid race with ksmd. > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 274 */ > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 275 if (ksm_execve(mm)) > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 276 goto err_ksm; > > "err" not set before the goto. The code should be: err = ksm_execve(mm); if (err) goto err_ksm; I will fix in the next version. > > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 277 > b6a2fea39318e43 Ollie Wild 2007-07-19 278 /* > b6a2fea39318e43 Ollie Wild 2007-07-19 279 * Place the stack at the largest stack address the architecture > b6a2fea39318e43 Ollie Wild 2007-07-19 280 * supports. Later, we'll move this to an appropriate place. We don't > b6a2fea39318e43 Ollie Wild 2007-07-19 281 * use STACK_TOP because that can depend on attributes which aren't > b6a2fea39318e43 Ollie Wild 2007-07-19 282 * configured yet. > b6a2fea39318e43 Ollie Wild 2007-07-19 283 */ > aacb3d17a73f644 Michal Hocko 2011-07-26 284 BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); > b6a2fea39318e43 Ollie Wild 2007-07-19 285 vma->vm_end = STACK_TOP_MAX; > b6a2fea39318e43 Ollie Wild 2007-07-19 286 vma->vm_start = vma->vm_end - PAGE_SIZE; > 1c71222e5f2393b Suren Baghdasaryan 2023-01-26 287 vm_flags_init(vma, VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP); > 3ed75eb8f1cd895 Coly Li 2007-10-18 288 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); > 462e635e5b73ba9 Tavis Ormandy 2010-12-09 289 > b6a2fea39318e43 Ollie Wild 2007-07-19 290 err = insert_vm_struct(mm, vma); > eaccbfa564e48c8 Luiz Fernando N. Capitulino 2009-01-06 291 if (err) > b6a2fea39318e43 Ollie Wild 2007-07-19 292 goto err; > b6a2fea39318e43 Ollie Wild 2007-07-19 293 > b6a2fea39318e43 Ollie Wild 2007-07-19 294 mm->stack_vm = mm->total_vm = 1; > d8ed45c5dcd455f Michel Lespinasse 2020-06-08 295 mmap_write_unlock(mm); > b6a2fea39318e43 Ollie Wild 2007-07-19 296 bprm->p = vma->vm_end - sizeof(void *); > b6a2fea39318e43 Ollie Wild 2007-07-19 297 return 0; > b6a2fea39318e43 Ollie Wild 2007-07-19 298 err: > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 299 ksm_exit(mm); > d282f6b19afd1a9 Jinjiang Tu 2024-03-22 300 err_ksm: > d8ed45c5dcd455f Michel Lespinasse 2020-06-08 301 mmap_write_unlock(mm); > f268dfe905d4682 Michal Hocko 2016-05-23 302 err_free: > b6a2fea39318e43 Ollie Wild 2007-07-19 303 bprm->vma = NULL; > 3928d4f5ee37cdc Linus Torvalds 2018-07-21 304 vm_area_free(vma); > b6a2fea39318e43 Ollie Wild 2007-07-19 @305 return err; > b6a2fea39318e43 Ollie Wild 2007-07-19 306 } >
On 25.03.24 03:24, Jinjiang Tu wrote: > > 在 2024/3/22 17:02, David Hildenbrand 写道: >> On 22.03.24 07:09, Jinjiang Tu wrote: >>> commit 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") inherits >>> MMF_VM_MERGE_ANY flag when a task calls execve(). Howerver, it doesn't >>> create the mm_slot, so ksmd will not try to scan this task. >>> >>> To fix it, allocate and add the mm_slot to ksm_mm_head in >>> __bprm_mm_init() >>> when the mm has MMF_VM_MERGE_ANY flag. >>> >>> Fixes: 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") >>> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> >>> --- >>> fs/exec.c | 10 ++++++++++ >>> include/linux/ksm.h | 13 +++++++++++++ >>> 2 files changed, 23 insertions(+) >>> >>> diff --git a/fs/exec.c b/fs/exec.c >>> index ff6f26671cfc..66202d016a0a 100644 >>> --- a/fs/exec.c >>> +++ b/fs/exec.c >>> @@ -67,6 +67,7 @@ >>> #include <linux/time_namespace.h> >>> #include <linux/user_events.h> >>> #include <linux/rseq.h> >>> +#include <linux/ksm.h> >>> #include <linux/uaccess.h> >>> #include <asm/mmu_context.h> >>> @@ -267,6 +268,13 @@ static int __bprm_mm_init(struct linux_binprm >>> *bprm) >>> goto err_free; >>> } >>> + /* >>> + * Need to be called with mmap write lock >>> + * held, to avoid race with ksmd. >>> + */ >>> + if (ksm_execve(mm)) >>> + goto err_ksm; >>> + >> >> But now, would we revert what insert_vm_struct() did? >> >> We're freeing the VMA later, but we might have accounted memory. >> >> >> What would be cleaner is doing the ksm_execve() before the >> insert_vm_struct(), and then cleaning up in case insert_vm_struct() >> failed. > In fact, ksm_execve() has been called before the insert_vm_struct() in > this patch. > Ahh, I missed that. Indeed, that works then.
diff --git a/fs/exec.c b/fs/exec.c index ff6f26671cfc..66202d016a0a 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -67,6 +67,7 @@ #include <linux/time_namespace.h> #include <linux/user_events.h> #include <linux/rseq.h> +#include <linux/ksm.h> #include <linux/uaccess.h> #include <asm/mmu_context.h> @@ -267,6 +268,13 @@ static int __bprm_mm_init(struct linux_binprm *bprm) goto err_free; } + /* + * Need to be called with mmap write lock + * held, to avoid race with ksmd. + */ + if (ksm_execve(mm)) + goto err_ksm; + /* * Place the stack at the largest stack address the architecture * supports. Later, we'll move this to an appropriate place. We don't @@ -288,6 +296,8 @@ static int __bprm_mm_init(struct linux_binprm *bprm) bprm->p = vma->vm_end - sizeof(void *); return 0; err: + ksm_exit(mm); +err_ksm: mmap_write_unlock(mm); err_free: bprm->vma = NULL; diff --git a/include/linux/ksm.h b/include/linux/ksm.h index 401348e9f92b..7e2b1de3996a 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -59,6 +59,14 @@ static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) return 0; } +static inline int ksm_execve(struct mm_struct *mm) +{ + if (test_bit(MMF_VM_MERGE_ANY, &mm->flags)) + return __ksm_enter(mm); + + return 0; +} + static inline void ksm_exit(struct mm_struct *mm) { if (test_bit(MMF_VM_MERGEABLE, &mm->flags)) @@ -107,6 +115,11 @@ static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) return 0; } +static inline int ksm_execve(struct mm_struct *mm) +{ + return 0; +} + static inline void ksm_exit(struct mm_struct *mm) { }
commit 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") inherits MMF_VM_MERGE_ANY flag when a task calls execve(). Howerver, it doesn't create the mm_slot, so ksmd will not try to scan this task. To fix it, allocate and add the mm_slot to ksm_mm_head in __bprm_mm_init() when the mm has MMF_VM_MERGE_ANY flag. Fixes: 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- fs/exec.c | 10 ++++++++++ include/linux/ksm.h | 13 +++++++++++++ 2 files changed, 23 insertions(+)