The patch titled
Subject: uprobes: turn xol_area->pages[2] into xol_area->page
has been added to the -mm mm-unstable branch. Its filename is
uprobes-turn-xol_area-pages-into-xol_area-page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/uprobes-turn-xol_area-pages-into-xol_area-page.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: uprobes: turn xol_area->pages[2] into xol_area->page
Date: Wed, 11 Sep 2024 15:14:37 +0200
Now that xol_mapping has its own ->fault() method we no longer need
xol_area->pages[1] == NULL, we need a single page.
Link: https://lkml.kernel.org/r/20240911131437.GC3448@xxxxxxxxxx
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/events/uprobes.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
--- a/kernel/events/uprobes.c~uprobes-turn-xol_area-pages-into-xol_area-page
+++ a/kernel/events/uprobes.c
@@ -99,7 +99,7 @@ struct xol_area {
atomic_t slot_count; /* number of in-use slots */
unsigned long *bitmap; /* 0 = free slot */
- struct page *pages[2];
+ struct page *page;
/*
* We keep the vma's vm_start rather than a pointer to the vma
* itself. The probed process or a naughty kernel module could make
@@ -1437,7 +1437,7 @@ static vm_fault_t xol_fault(const struct
{
struct xol_area *area = vma->vm_mm->uprobes_state.xol_area;
- vmf->page = area->pages[0];
+ vmf->page = area->page;
get_page(vmf->page);
return 0;
}
@@ -1512,10 +1512,9 @@ static struct xol_area *__create_xol_are
if (!area->bitmap)
goto free_area;
- area->pages[0] = alloc_page(GFP_HIGHUSER);
- if (!area->pages[0])
+ area->page = alloc_page(GFP_HIGHUSER);
+ if (!area->page)
goto free_bitmap;
- area->pages[1] = NULL;
area->vaddr = vaddr;
init_waitqueue_head(&area->wq);
@@ -1523,12 +1522,12 @@ static struct xol_area *__create_xol_are
set_bit(0, area->bitmap);
atomic_set(&area->slot_count, 1);
insns = arch_uprobe_trampoline(&insns_size);
- arch_uprobe_copy_ixol(area->pages[0], 0, insns, insns_size);
+ arch_uprobe_copy_ixol(area->page, 0, insns, insns_size);
if (!xol_add_vma(mm, area))
return area;
- __free_page(area->pages[0]);
+ __free_page(area->page);
free_bitmap:
kfree(area->bitmap);
free_area:
@@ -1570,7 +1569,7 @@ void uprobe_clear_state(struct mm_struct
if (!area)
return;
- put_page(area->pages[0]);
+ put_page(area->page);
kfree(area->bitmap);
kfree(area);
}
@@ -1637,7 +1636,7 @@ static unsigned long xol_get_insn_slot(s
if (unlikely(!xol_vaddr))
return 0;
- arch_uprobe_copy_ixol(area->pages[0], xol_vaddr,
+ arch_uprobe_copy_ixol(area->page, xol_vaddr,
&uprobe->arch.ixol, sizeof(uprobe->arch.ixol));
return xol_vaddr;
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
revert-uprobes-use-vm_special_mapping-close-functionality.patch
uprobes-introduce-the-global-struct-vm_special_mapping-xol_mapping.patch
uprobes-turn-xol_area-pages-into-xol_area-page.patch
