Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 3.12 71/72] x86/mm/hotplug: Pass sync_global_pgds() a correct argument in remove_pagetable() | Date | Mon, 23 Nov 2015 14:12:32 +0100 |
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From: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 5255e0a79fcc0ff47b387af92bd9ef5729b1b859 upstream.
When hot-adding memory after hot-removing memory, following call traces are shown:
kernel BUG at arch/x86/mm/init_64.c:206! ... [<ffffffff815e0c80>] kernel_physical_mapping_init+0x1b2/0x1d2 [<ffffffff815ced94>] init_memory_mapping+0x1d4/0x380 [<ffffffff8104aebd>] arch_add_memory+0x3d/0xd0 [<ffffffff815d03d9>] add_memory+0xb9/0x1b0 [<ffffffff81352415>] acpi_memory_device_add+0x1af/0x28e [<ffffffff81325dc4>] acpi_bus_device_attach+0x8c/0xf0 [<ffffffff813413b9>] acpi_ns_walk_namespace+0xc8/0x17f [<ffffffff81325d38>] ? acpi_bus_type_and_status+0xb7/0xb7 [<ffffffff81325d38>] ? acpi_bus_type_and_status+0xb7/0xb7 [<ffffffff813418ed>] acpi_walk_namespace+0x95/0xc5 [<ffffffff81326b4c>] acpi_bus_scan+0x9a/0xc2 [<ffffffff81326bff>] acpi_scan_bus_device_check+0x8b/0x12e [<ffffffff81326cb5>] acpi_scan_device_check+0x13/0x15 [<ffffffff81320122>] acpi_os_execute_deferred+0x25/0x32 [<ffffffff8107e02b>] process_one_work+0x17b/0x460 [<ffffffff8107edfb>] worker_thread+0x11b/0x400 [<ffffffff8107ece0>] ? rescuer_thread+0x400/0x400 [<ffffffff81085aef>] kthread+0xcf/0xe0 [<ffffffff81085a20>] ? kthread_create_on_node+0x140/0x140 [<ffffffff815fc76c>] ret_from_fork+0x7c/0xb0 [<ffffffff81085a20>] ? kthread_create_on_node+0x140/0x140
The patch-set fixes the issue.
This patch (of 2):
remove_pagetable() gets start argument and passes the argument to sync_global_pgds(). In this case, the argument must not be modified. If the argument is modified and passed to sync_global_pgds(), sync_global_pgds() does not correctly synchronize PGD to PGD entries of all processes MM since synchronized range of memory [start, end] is wrong.
Unfortunately the start argument is modified in remove_pagetable(). So this patch fixes the issue.
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Vlastimil Babka <vbabka@suse.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- arch/x86/mm/init_64.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index a93e32722ab1..427b536a5fd6 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -975,19 +975,20 @@ static void __meminit remove_pagetable(unsigned long start, unsigned long end, bool direct) { unsigned long next; + unsigned long addr; pgd_t *pgd; pud_t *pud; bool pgd_changed = false; - for (; start < end; start = next) { - next = pgd_addr_end(start, end); + for (addr = start; addr < end; addr = next) { + next = pgd_addr_end(addr, end); - pgd = pgd_offset_k(start); + pgd = pgd_offset_k(addr); if (!pgd_present(*pgd)) continue; pud = (pud_t *)pgd_page_vaddr(*pgd); - remove_pud_table(pud, start, next, direct); + remove_pud_table(pud, addr, next, direct); if (free_pud_table(pud, pgd)) pgd_changed = true; } -- 2.6.3
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