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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /arch/m68k/mm/hwtest.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
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>
Diffstat (limited to 'arch/m68k/mm/hwtest.c')
-rw-r--r--arch/m68k/mm/hwtest.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/arch/m68k/mm/hwtest.c b/arch/m68k/mm/hwtest.c
new file mode 100644
index 000000000..8ee7a3368
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+++ b/arch/m68k/mm/hwtest.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Tests for presence or absence of hardware registers.
+ * This code was originally in atari/config.c, but I noticed
+ * that it was also in drivers/nubus/nubus.c and I wanted to
+ * use it in hp300/config.c, so it seemed sensible to pull it
+ * out into its own file.
+ *
+ * The test is for use when trying to read a hardware register
+ * that isn't present would cause a bus error. We set up a
+ * temporary handler so that this doesn't kill the kernel.
+ *
+ * There is a test-by-reading and a test-by-writing; I present
+ * them here complete with the comments from the original atari
+ * config.c...
+ * -- PMM <pmaydell@chiark.greenend.org.uk>, 05/1998
+ */
+
+/* This function tests for the presence of an address, specially a
+ * hardware register address. It is called very early in the kernel
+ * initialization process, when the VBR register isn't set up yet. On
+ * an Atari, it still points to address 0, which is unmapped. So a bus
+ * error would cause another bus error while fetching the exception
+ * vector, and the CPU would do nothing at all. So we needed to set up
+ * a temporary VBR and a vector table for the duration of the test.
+ */
+
+#include <linux/module.h>
+
+#include <asm/hwtest.h>
+
+int hwreg_present(volatile void *regp)
+{
+ int ret = 0;
+ unsigned long flags;
+ long save_sp, save_vbr;
+ long tmp_vectors[3];
+
+ local_irq_save(flags);
+ __asm__ __volatile__ (
+ "movec %/vbr,%2\n\t"
+ "movel #Lberr1,%4@(8)\n\t"
+ "movec %4,%/vbr\n\t"
+ "movel %/sp,%1\n\t"
+ "moveq #0,%0\n\t"
+ "tstb %3@\n\t"
+ "nop\n\t"
+ "moveq #1,%0\n"
+ "Lberr1:\n\t"
+ "movel %1,%/sp\n\t"
+ "movec %2,%/vbr"
+ : "=&d" (ret), "=&r" (save_sp), "=&r" (save_vbr)
+ : "a" (regp), "a" (tmp_vectors)
+ );
+ local_irq_restore(flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(hwreg_present);
+
+/* Basically the same, but writes a value into a word register, protected
+ * by a bus error handler. Returns 1 if successful, 0 otherwise.
+ */
+
+int hwreg_write(volatile void *regp, unsigned short val)
+{
+ int ret;
+ unsigned long flags;
+ long save_sp, save_vbr;
+ long tmp_vectors[3];
+
+ local_irq_save(flags);
+ __asm__ __volatile__ (
+ "movec %/vbr,%2\n\t"
+ "movel #Lberr2,%4@(8)\n\t"
+ "movec %4,%/vbr\n\t"
+ "movel %/sp,%1\n\t"
+ "moveq #0,%0\n\t"
+ "movew %5,%3@\n\t"
+ "nop\n\t"
+ /*
+ * If this nop isn't present, 'ret' may already be loaded
+ * with 1 at the time the bus error happens!
+ */
+ "moveq #1,%0\n"
+ "Lberr2:\n\t"
+ "movel %1,%/sp\n\t"
+ "movec %2,%/vbr"
+ : "=&d" (ret), "=&r" (save_sp), "=&r" (save_vbr)
+ : "a" (regp), "a" (tmp_vectors), "g" (val)
+ );
+ local_irq_restore(flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(hwreg_write);
+