Replace uvm_km_alloc(9) calls with km_alloc(9) calls. Make the copied ROM

contents executable using pmap_kenter_pa(9) since uvm stops us from doing
so using higher-level interfaces (for good reasons).
Maintaining W^X of course!

ok mpi@

diff --git a/sys/dev/ic/sti.c b/sys/dev/ic/sti.c
index aa9dc11..87a9fa3 100644 (file)
--- a/sys/dev/ic/sti.c
+++ b/sys/dev/ic/sti.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: sti.c,v 1.80 2020/05/25 09:55:48 jsg Exp $    */
+/*     $OpenBSD: sti.c,v 1.81 2021/04/29 15:12:14 kettenis Exp $       */
 
 /*
  * Copyright (c) 2000-2003 Michael Shalayeff
@@ -211,7 +211,9 @@ sti_rom_setup(struct sti_rom *rom, bus_space_tag_t iot, bus_space_tag_t memt,
     bus_space_handle_t romh, bus_addr_t *bases, u_int codebase)
 {
        struct sti_dd *dd;
-       int error, size, i;
+       int size, i;
+       vaddr_t va;
+       paddr_t pa;
 
        STI_ENABLE_ROM(rom->rom_softc);
 
@@ -315,12 +317,13 @@ sti_rom_setup(struct sti_rom *rom, bus_space_tag_t iot, bus_space_tag_t memt,
                return (EINVAL);
        }
 
-       if (!(rom->rom_code = uvm_km_alloc(kernel_map, round_page(size)))) {
+       if (!(rom->rom_code = km_alloc(round_page(size), &kv_any,
+           &kp_zero, &kd_waitok))) {
                printf(": cannot allocate %u bytes for code\n", size);
                return (ENOMEM);
        }
 #ifdef STIDEBUG
-       printf("code=0x%lx[%x]\n", rom->rom_code, size);
+       printf("code=%p[%x]\n", rom->rom_code, size);
 #endif
 
        /*
@@ -330,7 +333,7 @@ sti_rom_setup(struct sti_rom *rom, bus_space_tag_t iot, bus_space_tag_t memt,
        STI_ENABLE_ROM(rom->rom_softc);
 
        if (rom->rom_devtype == STI_DEVTYPE1) {
-               u_int8_t *p = (u_int8_t *)rom->rom_code;
+               u_int8_t *p = rom->rom_code;
                u_int32_t addr, eaddr;
 
                for (addr = dd->dd_pacode[STI_BEGIN], eaddr = addr + size * 4;
@@ -339,17 +342,24 @@ sti_rom_setup(struct sti_rom *rom, bus_space_tag_t iot, bus_space_tag_t memt,
 
        } else  /* STI_DEVTYPE4 */
                bus_space_read_raw_region_4(memt, romh,
-                   dd->dd_pacode[STI_BEGIN], (u_int8_t *)rom->rom_code,
-                   size);
+                   dd->dd_pacode[STI_BEGIN], rom->rom_code, size);
 
        STI_DISABLE_ROM(rom->rom_softc);
 
-       if ((error = uvm_map_protect(kernel_map, rom->rom_code,
-           rom->rom_code + round_page(size), PROT_READ | PROT_EXEC, FALSE))) {
-               printf(": uvm_map_protect failed (%d)\n", error);
-               uvm_km_free(kernel_map, rom->rom_code, round_page(size));
-               return (error);
+       /*
+        * Remap the ROM code as executable.  This happens to be the
+        * only place in the OpenBSD kernel where we need to do this.
+        * Since the kernel (deliberately) doesn't provide a
+        * high-level interface to map kernel memory as executable we
+        * use low-level pmap calls for this.
+        */
+       for (va = (vaddr_t)rom->rom_code;
+            va < (vaddr_t)rom->rom_code + round_page(size);
+            va += PAGE_SIZE) {
+               pmap_extract(pmap_kernel(), va, &pa);
+               pmap_kenter_pa(va, pa, PROT_READ | PROT_EXEC);
        }
+       pmap_update(pmap_kernel());
 
        /*
         * Setup code function pointers.