treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

1 files changed, 160 insertions, 0 deletions

diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
new file mode 100644
index 000000000..70403e968
--- /dev/null
+++ b/arch/arm/mm/idmap.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mm_types.h>
+#include <linux/pgtable.h>
+
+#include <asm/cputype.h>
+#include <asm/idmap.h>
+#include <asm/hwcap.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <asm/system_info.h>
+#include <asm/uaccess.h>
+
+/*
+ * Note: accesses outside of the kernel image and the identity map area
+ * are not supported on any CPU using the idmap tables as its current
+ * page tables.
+ */
+pgd_t *idmap_pgd __ro_after_init;
+long long arch_phys_to_idmap_offset __ro_after_init;
+
+#ifdef CONFIG_ARM_LPAE
+static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
+	unsigned long prot)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	if (pud_none_or_clear_bad(pud) || (pud_val(*pud) & L_PGD_SWAPPER)) {
+		pmd = pmd_alloc_one(&init_mm, addr);
+		if (!pmd) {
+			pr_warn("Failed to allocate identity pmd.\n");
+			return;
+		}
+		/*
+		 * Copy the original PMD to ensure that the PMD entries for
+		 * the kernel image are preserved.
+		 */
+		if (!pud_none(*pud))
+			memcpy(pmd, pmd_offset(pud, 0),
+			       PTRS_PER_PMD * sizeof(pmd_t));
+		pud_populate(&init_mm, pud, pmd);
+		pmd += pmd_index(addr);
+	} else
+		pmd = pmd_offset(pud, addr);
+
+	do {
+		next = pmd_addr_end(addr, end);
+		*pmd = __pmd((addr & PMD_MASK) | prot);
+		flush_pmd_entry(pmd);
+	} while (pmd++, addr = next, addr != end);
+}
+#else	/* !CONFIG_ARM_LPAE */
+static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
+	unsigned long prot)
+{
+	pmd_t *pmd = pmd_offset(pud, addr);
+
+	addr = (addr & PMD_MASK) | prot;
+	pmd[0] = __pmd(addr);
+	addr += SECTION_SIZE;
+	pmd[1] = __pmd(addr);
+	flush_pmd_entry(pmd);
+}
+#endif	/* CONFIG_ARM_LPAE */
+
+static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
+	unsigned long prot)
+{
+	p4d_t *p4d = p4d_offset(pgd, addr);
+	pud_t *pud = pud_offset(p4d, addr);
+	unsigned long next;
+
+	do {
+		next = pud_addr_end(addr, end);
+		idmap_add_pmd(pud, addr, next, prot);
+	} while (pud++, addr = next, addr != end);
+}
+
+static void identity_mapping_add(pgd_t *pgd, const char *text_start,
+				 const char *text_end, unsigned long prot)
+{
+	unsigned long addr, end;
+	unsigned long next;
+
+#ifdef CONFIG_XIP_KERNEL
+	addr = (phys_addr_t)(text_start) - XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
+		+ CONFIG_XIP_PHYS_ADDR;
+	end = (phys_addr_t)(text_end) - XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
+		+ CONFIG_XIP_PHYS_ADDR;
+#else
+	addr = virt_to_idmap(text_start);
+	end = virt_to_idmap(text_end);
+#endif
+	pr_info("Setting up static identity map for 0x%lx - 0x%lx\n", addr, end);
+
+	prot |= PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF;
+
+	if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale_family())
+		prot |= PMD_BIT4;
+
+	pgd += pgd_index(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		idmap_add_pud(pgd, addr, next, prot);
+	} while (pgd++, addr = next, addr != end);
+}
+
+extern char  __idmap_text_start[], __idmap_text_end[];
+
+static int __init init_static_idmap(void)
+{
+	idmap_pgd = pgd_alloc(&init_mm);
+	if (!idmap_pgd)
+		return -ENOMEM;
+
+	identity_mapping_add(idmap_pgd, __idmap_text_start,
+			     __idmap_text_end, 0);
+
+	/* Flush L1 for the hardware to see this page table content */
+	if (!(elf_hwcap & HWCAP_LPAE))
+		flush_cache_louis();
+
+	return 0;
+}
+early_initcall(init_static_idmap);
+
+/*
+ * In order to soft-boot, we need to switch to a 1:1 mapping for the
+ * cpu_reset functions. This will then ensure that we have predictable
+ * results when turning off the mmu.
+ */
+void setup_mm_for_reboot(void)
+{
+	/*
+	 * With CONFIG_CPU_TTBR0_PAN enabled, TTBCR.EPD0 is set whenever
+	 * user-space access is disabled in order to block TTBR0 page-table
+	 * walks.  The identity mapping lives at low (user-space) virtual
+	 * addresses and can only be reached via TTBR0, so we must re-enable
+	 * those walks before switching page tables.  On non-PAN kernels this
+	 * is a no-op.
+	 */
+	if (IS_ENABLED(CONFIG_CPU_TTBR0_PAN))
+		uaccess_save_and_enable();
+
+	/* Switch to the identity mapping. */
+	cpu_switch_mm(idmap_pgd, &init_mm);
+	local_flush_bp_all();
+
+#ifdef CONFIG_CPU_HAS_ASID
+	/*
+	 * We don't have a clean ASID for the identity mapping, which
+	 * may clash with virtual addresses of the previous page tables
+	 * and therefore potentially in the TLB.
+	 */
+	local_flush_tlb_all();
+#endif
+}