summaryrefslogtreecommitdiffstats
path: root/lib/extable.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /lib/extable.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'lib/extable.c')
-rw-r--r--lib/extable.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/lib/extable.c b/lib/extable.c
new file mode 100644
index 000000000..9c9f40bd2
--- /dev/null
+++ b/lib/extable.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Derived from arch/ppc/mm/extable.c and arch/i386/mm/extable.c.
+ *
+ * Copyright (C) 2004 Paul Mackerras, IBM Corp.
+ */
+
+#include <linux/bsearch.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sort.h>
+#include <linux/uaccess.h>
+#include <linux/extable.h>
+
+#ifndef ARCH_HAS_RELATIVE_EXTABLE
+#define ex_to_insn(x) ((x)->insn)
+#else
+static inline unsigned long ex_to_insn(const struct exception_table_entry *x)
+{
+ return (unsigned long)&x->insn + x->insn;
+}
+#endif
+
+#ifndef ARCH_HAS_RELATIVE_EXTABLE
+#define swap_ex NULL
+#else
+static void swap_ex(void *a, void *b, int size)
+{
+ struct exception_table_entry *x = a, *y = b, tmp;
+ int delta = b - a;
+
+ tmp = *x;
+ x->insn = y->insn + delta;
+ y->insn = tmp.insn - delta;
+
+#ifdef swap_ex_entry_fixup
+ swap_ex_entry_fixup(x, y, tmp, delta);
+#else
+ x->fixup = y->fixup + delta;
+ y->fixup = tmp.fixup - delta;
+#endif
+}
+#endif /* ARCH_HAS_RELATIVE_EXTABLE */
+
+/*
+ * The exception table needs to be sorted so that the binary
+ * search that we use to find entries in it works properly.
+ * This is used both for the kernel exception table and for
+ * the exception tables of modules that get loaded.
+ */
+static int cmp_ex_sort(const void *a, const void *b)
+{
+ const struct exception_table_entry *x = a, *y = b;
+
+ /* avoid overflow */
+ if (ex_to_insn(x) > ex_to_insn(y))
+ return 1;
+ if (ex_to_insn(x) < ex_to_insn(y))
+ return -1;
+ return 0;
+}
+
+void sort_extable(struct exception_table_entry *start,
+ struct exception_table_entry *finish)
+{
+ sort(start, finish - start, sizeof(struct exception_table_entry),
+ cmp_ex_sort, swap_ex);
+}
+
+#ifdef CONFIG_MODULES
+/*
+ * If the exception table is sorted, any referring to the module init
+ * will be at the beginning or the end.
+ */
+void trim_init_extable(struct module *m)
+{
+ /*trim the beginning*/
+ while (m->num_exentries &&
+ within_module_init(ex_to_insn(&m->extable[0]), m)) {
+ m->extable++;
+ m->num_exentries--;
+ }
+ /*trim the end*/
+ while (m->num_exentries &&
+ within_module_init(ex_to_insn(&m->extable[m->num_exentries - 1]),
+ m))
+ m->num_exentries--;
+}
+#endif /* CONFIG_MODULES */
+
+static int cmp_ex_search(const void *key, const void *elt)
+{
+ const struct exception_table_entry *_elt = elt;
+ unsigned long _key = *(unsigned long *)key;
+
+ /* avoid overflow */
+ if (_key > ex_to_insn(_elt))
+ return 1;
+ if (_key < ex_to_insn(_elt))
+ return -1;
+ return 0;
+}
+
+/*
+ * Search one exception table for an entry corresponding to the
+ * given instruction address, and return the address of the entry,
+ * or NULL if none is found.
+ * We use a binary search, and thus we assume that the table is
+ * already sorted.
+ */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *base,
+ const size_t num,
+ unsigned long value)
+{
+ return bsearch(&value, base, num,
+ sizeof(struct exception_table_entry), cmp_ex_search);
+}