From b4ebbb876dca9327cc964138f5558ca3c6832392 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Tue, 19 Apr 2016 09:25:08 +0100 Subject: [PATCH] MIPS: mm: Be more explicit about PTE mode bit handling The XPA case in iPTE_SW or's in software mode bits to the pte_low value (which is what actually ends up in the high 32 bits of EntryLo...). It does this presuming that only bits in the upper 16 bits of the 32 bit pte_low value will be set. Make this assumption explicit with a BUG_ON. A similar assumption is made for the hardware mode bits, which are or'd in with a single ori instruction. Make that assumption explicit with a BUG_ON too. Signed-off-by: Paul Burton Cc: James Hogan Cc: Paul Gortmaker Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13122/ Signed-off-by: Ralf Baechle --- arch/mips/mm/tlbex.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 2e9b43637743..6f20b42be979 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -1641,15 +1641,17 @@ static void iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, unsigned int mode, unsigned int scratch) { -#ifdef CONFIG_PHYS_ADDR_T_64BIT unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY); + unsigned int swmode = mode & ~hwmode; if (config_enabled(CONFIG_XPA) && !cpu_has_64bits) { - uasm_i_lui(p, scratch, (mode >> 16)); + uasm_i_lui(p, scratch, swmode >> 16); uasm_i_or(p, pte, pte, scratch); - } else -#endif - uasm_i_ori(p, pte, pte, mode); + BUG_ON(swmode & 0xffff); + } else { + uasm_i_ori(p, pte, pte, mode); + } + #ifdef CONFIG_SMP # ifdef CONFIG_PHYS_ADDR_T_64BIT if (cpu_has_64bits) @@ -1668,6 +1670,7 @@ iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, /* no uasm_i_nop needed */ uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr); uasm_i_ori(p, pte, pte, hwmode); + BUG_ON(hwmode & ~0xffff); uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr); uasm_il_beqz(p, r, pte, label_smp_pgtable_change); /* no uasm_i_nop needed */ @@ -1689,6 +1692,7 @@ iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, if (!cpu_has_64bits) { uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr); uasm_i_ori(p, pte, pte, hwmode); + BUG_ON(hwmode & ~0xffff); uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr); uasm_i_lw(p, pte, 0, ptr); } -- 2.20.1