Messages in this thread Patch in this message | | | From | Arvind Sankar <> | Subject | [PATCH] x86/mm/ident_map: Check for errors from ident_pud_init() | Date | Tue, 27 Oct 2020 19:06:48 -0400 |
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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.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Fixes: ea3b5e60ce80 ("x86/mm/ident_map: Add 5-level paging support") --- arch/x86/mm/ident_map.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c index fe7a12599d8e..5ecb0883cc88 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 +74,17 @@ 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)); } -- 2.26.2
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