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coredump: remove vma linked list walk

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Use the Maple Tree iterator instead.  This is too complicated for the VMA
iterator to handle, so let's open-code it for now.  If this turns out to
be a common pattern, we can migrate it to common code.

Link: https://lkml.kernel.org/r/20220906194824.2110408-41-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2022-09-06 19:48:56 +00:00 committed by Andrew Morton
parent cbd43755ad
commit 182ea1d717
1 changed files with 12 additions and 22 deletions
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34
fs/coredump.c
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@ -1072,30 +1072,20 @@ whole:
return vma->vm_end - vma->vm_start;
}
static struct vm_area_struct *first_vma(struct task_struct *tsk,
struct vm_area_struct *gate_vma)
{
struct vm_area_struct *ret = tsk->mm->mmap;
if (ret)
return ret;
return gate_vma;
}
/*
* Helper function for iterating across a vma list. It ensures that the caller
* will visit `gate_vma' prior to terminating the search.
*/
static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
static struct vm_area_struct *coredump_next_vma(struct ma_state *mas,
struct vm_area_struct *vma,
struct vm_area_struct *gate_vma)
{
struct vm_area_struct *ret;
ret = this_vma->vm_next;
if (ret)
return ret;
if (this_vma == gate_vma)
if (gate_vma && (vma == gate_vma))
return NULL;
vma = mas_next(mas, ULONG_MAX);
if (vma)
return vma;
return gate_vma;
}
@ -1119,9 +1109,10 @@ static void free_vma_snapshot(struct coredump_params *cprm)
*/
static bool dump_vma_snapshot(struct coredump_params *cprm)
{
struct vm_area_struct *vma, *gate_vma;
struct vm_area_struct *gate_vma, *vma = NULL;
struct mm_struct *mm = current->mm;
int i;
MA_STATE(mas, &mm->mm_mt, 0, 0);
int i = 0;
/*
* Once the stack expansion code is fixed to not change VMA bounds
@ -1141,8 +1132,7 @@ static bool dump_vma_snapshot(struct coredump_params *cprm)
return false;
}
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
vma = next_vma(vma, gate_vma), i++) {
while ((vma = coredump_next_vma(&mas, vma, gate_vma)) != NULL) {
struct core_vma_metadata *m = cprm->vma_meta + i;
m->start = vma->vm_start;
@ -1150,10 +1140,10 @@ static bool dump_vma_snapshot(struct coredump_params *cprm)
m->flags = vma->vm_flags;
m->dump_size = vma_dump_size(vma, cprm->mm_flags);
m->pgoff = vma->vm_pgoff;
m->file = vma->vm_file;
if (m->file)
get_file(m->file);
i++;
}
mmap_write_unlock(mm);