[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH MM-PART3 v3 9/9] xen/arm: mm: Remove set_pte_flags_on_range()
set_pte_flags_on_range() is yet another function that will open-code update to a specific range in the Xen page-tables. It can be completely dropped by using either modify_xen_mappings() or destroy_xen_mappings(). Note that modify_xen_mappings() will keep the field 'pxn' cleared for the all the cases. This is because the field is RES0 for the stage-1 hypervisor as only a single VA range is supported (see D5.4.5 in DDI0487D.b). Signed-off-by: Julien Grall <julien.grall@xxxxxxx> Reviewed-by: Andrii Anisov <andrii_anisov@xxxxxxxx> --- Changes in v3: - Update commit message to explain why the field 'pxn' is now cleared. Changes in v2: - Add missing newline in panic - Add Andrii's reviewed-by --- xen/arch/arm/mm.c | 58 ++++++++++--------------------------------------------- 1 file changed, 10 insertions(+), 48 deletions(-) diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 46bc3d8075..35dc1f7e71 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -1255,52 +1255,6 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int flags) return xen_pt_update(s, INVALID_MFN, (e - s) >> PAGE_SHIFT, flags); } -enum mg { mg_clear, mg_ro, mg_rw, mg_rx }; -static void set_pte_flags_on_range(const char *p, unsigned long l, enum mg mg) -{ - lpae_t pte; - int i; - - ASSERT(is_kernel(p) && is_kernel(p + l)); - - /* Can only guard in page granularity */ - ASSERT(!((unsigned long) p & ~PAGE_MASK)); - ASSERT(!(l & ~PAGE_MASK)); - - for ( i = (p - _start) / PAGE_SIZE; - i < (p + l - _start) / PAGE_SIZE; - i++ ) - { - pte = xen_xenmap[i]; - switch ( mg ) - { - case mg_clear: - pte.pt.valid = 0; - break; - case mg_ro: - pte.pt.valid = 1; - pte.pt.pxn = 1; - pte.pt.xn = 1; - pte.pt.ro = 1; - break; - case mg_rw: - pte.pt.valid = 1; - pte.pt.pxn = 1; - pte.pt.xn = 1; - pte.pt.ro = 0; - break; - case mg_rx: - pte.pt.valid = 1; - pte.pt.pxn = 0; - pte.pt.xn = 0; - pte.pt.ro = 1; - break; - } - write_pte(xen_xenmap + i, pte); - } - flush_xen_tlb_local(); -} - /* Release all __init and __initdata ranges to be reused */ void free_init_memory(void) { @@ -1309,8 +1263,12 @@ void free_init_memory(void) uint32_t insn; unsigned int i, nr = len / sizeof(insn); uint32_t *p; + int rc; - set_pte_flags_on_range(__init_begin, len, mg_rw); + rc = modify_xen_mappings((unsigned long)__init_begin, + (unsigned long)__init_end, PAGE_HYPERVISOR_RW); + if ( rc ) + panic("Unable to map RW the init section (rc = %d)\n", rc); /* * From now on, init will not be used for execution anymore, @@ -1328,7 +1286,11 @@ void free_init_memory(void) for ( i = 0; i < nr; i++ ) *(p + i) = insn; - set_pte_flags_on_range(__init_begin, len, mg_clear); + rc = destroy_xen_mappings((unsigned long)__init_begin, + (unsigned long)__init_end); + if ( rc ) + panic("Unable to remove the init section (rc = %d)\n", rc); + init_domheap_pages(pa, pa + len); printk("Freed %ldkB init memory.\n", (long)(__init_end-__init_begin)>>10); } -- 2.11.0 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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