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| author | Arvind Sankar <nivedita@alum.mit.edu> | 2020-10-27 19:06:48 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-29 13:46:51 +0100 |
| commit | 3d0db14d7b9513a72567191feb33de7ee89b055b (patch) | |
| tree | ae83df5682305ddf79ce9afb9e90ebff542a02d1 /arch | |
| parent | 1100b71de7e5ebe01a73b7a162666568839b10fa (diff) | |
| download | linux-3d0db14d7b9513a72567191feb33de7ee89b055b.tar.gz linux-3d0db14d7b9513a72567191feb33de7ee89b055b.tar.bz2 linux-3d0db14d7b9513a72567191feb33de7ee89b055b.zip | |
x86/mm/ident_map: Check for errors from ident_pud_init()
[ Upstream commit 1fcd009102ee02e217f2e7635ab65517d785da8e ]
Commit
ea3b5e60ce80 ("x86/mm/ident_map: Add 5-level paging support")
added ident_p4d_init() to support 5-level paging, but this function
doesn't check and return errors from ident_pud_init().
For example, the decompressor stub uses this code to create an identity
mapping. If it runs out of pages while trying to allocate a PMD
pagetable, the error will be currently ignored.
Fix this to propagate errors.
[ bp: Space out statements for better readability. ]
Fixes: ea3b5e60ce80 ("x86/mm/ident_map: Add 5-level paging support")
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/20201027230648.1885111-1-nivedita@alum.mit.edu
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/mm/ident_map.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c index ab33a32df2a8..407fa1df470e 100644 --- a/arch/x86/mm/ident_map.c +++ b/arch/x86/mm/ident_map.c @@ -62,6 +62,7 @@ static int ident_p4d_init(struct x86_mapping_info *info, p4d_t *p4d_page, unsigned long addr, unsigned long end) { unsigned long next; + int result; for (; addr < end; addr = next) { p4d_t *p4d = p4d_page + p4d_index(addr); @@ -73,13 +74,20 @@ static int ident_p4d_init(struct x86_mapping_info *info, p4d_t *p4d_page, if (p4d_present(*p4d)) { pud = pud_offset(p4d, 0); - ident_pud_init(info, pud, addr, next); + result = ident_pud_init(info, pud, addr, next); + if (result) + return result; + continue; } pud = (pud_t *)info->alloc_pgt_page(info->context); if (!pud) return -ENOMEM; - ident_pud_init(info, pud, addr, next); + + result = ident_pud_init(info, pud, addr, next); + if (result) + return result; + set_p4d(p4d, __p4d(__pa(pud) | info->kernpg_flag)); } |