From: Tiwei Bie Date: Mon, 2 Mar 2026 23:52:24 +0000 (+0800) Subject: um: Fix pte_read() and pte_exec() for kernel mappings X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd4126d48f7f61928c18498629ca19a0f846d0c4;p=thirdparty%2Flinux.git um: Fix pte_read() and pte_exec() for kernel mappings The pte_read() and pte_exec() helpers are only used during the TLB sync to determine the read/exec permissions for mmap. However, for kernel mappings, they will always return 0. This leads to kern_map() having to unconditionally set the exec flag to 1 and the read flag unexpectedly always being 0. Remove the unnecessary check for the _PAGE_USER bit in these helpers to ensure that the kernel mapping permissions can be correctly determined. Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20260302235224.1915380-3-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg --- diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h index 3b42b0f45bf6c..e156ef6f4fdb6 100644 --- a/arch/um/include/asm/pgtable.h +++ b/arch/um/include/asm/pgtable.h @@ -121,13 +121,12 @@ static inline int pte_none(pte_t pte) */ static inline int pte_read(pte_t pte) { - return((pte_get_bits(pte, _PAGE_USER)) && - !(pte_get_bits(pte, _PAGE_PROTNONE))); + return !pte_get_bits(pte, _PAGE_PROTNONE); } -static inline int pte_exec(pte_t pte){ - return((pte_get_bits(pte, _PAGE_USER)) && - !(pte_get_bits(pte, _PAGE_PROTNONE))); +static inline int pte_exec(pte_t pte) +{ + return !pte_get_bits(pte, _PAGE_PROTNONE); } static inline int pte_write(pte_t pte) diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c index 5386ab2d0da50..1f175716b4747 100644 --- a/arch/um/kernel/tlb.c +++ b/arch/um/kernel/tlb.c @@ -29,10 +29,9 @@ static int kern_map(struct mm_id *mm_idp, unsigned long virt, unsigned long len, int prot, int phys_fd, unsigned long long offset) { - /* TODO: Why is executable needed to be always set in the kernel? */ return os_map_memory((void *)virt, phys_fd, offset, len, prot & UM_PROT_READ, prot & UM_PROT_WRITE, - 1); + prot & UM_PROT_EXEC); } static int kern_unmap(struct mm_id *mm_idp,