From: Hugh Dickins Date: Fri, 2 Dec 2005 15:59:59 +0000 (+0000) Subject: [SCSI] sg and st unmap_user_pages allow PageReserved X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=032c09d76cdb448484859cc84dac4bba8f5f8f14;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git [SCSI] sg and st unmap_user_pages allow PageReserved 2.6.15-rc1 made sg's st_unmap_user_pages and st's sgl_unmap_user_pages BUG on a PageReserved page. But that's wrong: they could be unmapping the ZERO_PAGE, which is marked PG_reserved; and perhaps others (while get_user_pages is still permitted on VM_PFNMAP areas - that may change). More change is needed here: sg claims to dirty even pages written from, and st claims not to dirty even pages read into; and SetPageDirty is not adequate for this nowadays. Fixes to those follow in a later patch: for the moment just fix the 2.6.15 regression. Signed-off-by: Hugh Dickins Acked-by: Nick Piggin Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 72ec59456e6..6de7ff9faf2 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1878,8 +1878,6 @@ st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages, for (i=0; i < nr_pages; i++) { struct page *page = sgl[i].page; - /* XXX: just for debug. Remove when PageReserved is removed */ - BUG_ON(PageReserved(page)); if (dirtied) SetPageDirty(page); /* unlock_page(page); */ diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index b1056d290ae..7ac6ea141ff 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -4525,8 +4525,6 @@ static int sgl_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_p for (i=0; i < nr_pages; i++) { struct page *page = sgl[i].page; - /* XXX: just for debug. Remove when PageReserved is removed */ - BUG_ON(PageReserved(page)); if (dirtied) SetPageDirty(page); /* FIXME: cache flush missing for rw==READ