From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux 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 ... --- tools/objtool/special.c | 169 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 169 insertions(+) create mode 100644 tools/objtool/special.c (limited to 'tools/objtool/special.c') diff --git a/tools/objtool/special.c b/tools/objtool/special.c new file mode 100644 index 000000000..2a533afbc --- /dev/null +++ b/tools/objtool/special.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2015 Josh Poimboeuf + */ + +/* + * This file reads all the special sections which have alternate instructions + * which can be patched in or redirected to at runtime. + */ + +#include +#include + +#include +#include +#include +#include + +struct special_entry { + const char *sec; + bool group, jump_or_nop; + unsigned char size, orig, new; + unsigned char orig_len, new_len; /* group only */ + unsigned char feature; /* ALTERNATIVE macro CPU feature */ + unsigned char key; /* jump_label key */ +}; + +static const struct special_entry entries[] = { + { + .sec = ".altinstructions", + .group = true, + .size = ALT_ENTRY_SIZE, + .orig = ALT_ORIG_OFFSET, + .orig_len = ALT_ORIG_LEN_OFFSET, + .new = ALT_NEW_OFFSET, + .new_len = ALT_NEW_LEN_OFFSET, + .feature = ALT_FEATURE_OFFSET, + }, + { + .sec = "__jump_table", + .jump_or_nop = true, + .size = JUMP_ENTRY_SIZE, + .orig = JUMP_ORIG_OFFSET, + .new = JUMP_NEW_OFFSET, + .key = JUMP_KEY_OFFSET, + }, + { + .sec = "__ex_table", + .size = EX_ENTRY_SIZE, + .orig = EX_ORIG_OFFSET, + .new = EX_NEW_OFFSET, + }, + {}, +}; + +void __weak arch_handle_alternative(struct special_alt *alt) +{ +} + +static void reloc_to_sec_off(struct reloc *reloc, struct section **sec, + unsigned long *off) +{ + *sec = reloc->sym->sec; + *off = reloc->sym->offset + reloc_addend(reloc); +} + +static int get_alt_entry(struct elf *elf, const struct special_entry *entry, + struct section *sec, int idx, + struct special_alt *alt) +{ + struct reloc *orig_reloc, *new_reloc; + unsigned long offset; + + offset = idx * entry->size; + + alt->group = entry->group; + alt->jump_or_nop = entry->jump_or_nop; + + if (alt->group) { + alt->orig_len = *(unsigned char *)(sec->data->d_buf + offset + + entry->orig_len); + alt->new_len = *(unsigned char *)(sec->data->d_buf + offset + + entry->new_len); + alt->feature = *(unsigned int *)(sec->data->d_buf + offset + + entry->feature); + } + + orig_reloc = find_reloc_by_dest(elf, sec, offset + entry->orig); + if (!orig_reloc) { + ERROR_FUNC(sec, offset + entry->orig, "can't find orig reloc"); + return -1; + } + + reloc_to_sec_off(orig_reloc, &alt->orig_sec, &alt->orig_off); + + arch_handle_alternative(alt); + + if (!entry->group || alt->new_len) { + new_reloc = find_reloc_by_dest(elf, sec, offset + entry->new); + if (!new_reloc) { + ERROR_FUNC(sec, offset + entry->new, "can't find new reloc"); + return -1; + } + + reloc_to_sec_off(new_reloc, &alt->new_sec, &alt->new_off); + + /* _ASM_EXTABLE_EX hack */ + if (alt->new_off >= 0x7ffffff0) + alt->new_off -= 0x7ffffff0; + } + + if (entry->key) { + struct reloc *key_reloc; + + key_reloc = find_reloc_by_dest(elf, sec, offset + entry->key); + if (!key_reloc) { + ERROR_FUNC(sec, offset + entry->key, "can't find key reloc"); + return -1; + } + alt->key_addend = reloc_addend(key_reloc); + } + + return 0; +} + +/* + * Read all the special sections and create a list of special_alt structs which + * describe all the alternate instructions which can be patched in or + * redirected to at runtime. + */ +int special_get_alts(struct elf *elf, struct list_head *alts) +{ + const struct special_entry *entry; + struct section *sec; + unsigned int nr_entries; + struct special_alt *alt; + int idx; + + INIT_LIST_HEAD(alts); + + for (entry = entries; entry->sec; entry++) { + sec = find_section_by_name(elf, entry->sec); + if (!sec) + continue; + + if (sec_size(sec) % entry->size != 0) { + ERROR("%s size not a multiple of %d", sec->name, entry->size); + return -1; + } + + nr_entries = sec_size(sec) / entry->size; + + for (idx = 0; idx < nr_entries; idx++) { + alt = malloc(sizeof(*alt)); + if (!alt) { + ERROR_GLIBC("malloc failed"); + return -1; + } + memset(alt, 0, sizeof(*alt)); + + if (get_alt_entry(elf, entry, sec, idx, alt)) + return -1; + + list_add_tail(&alt->list, alts); + } + } + + return 0; +} -- cgit v1.3.1