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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-25 20:01:34 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-25 20:01:34 +0300
commitd710d370c4911e83da5d2bc43d4a2c3b56bd27e7 (patch)
tree9e7a702654feb88e2555c1bf41f71ef4a58b25aa /arch/s390/mm/extable.c
parent744465da705f7d8cd893e97738a47b91f3321ce2 (diff)
parentc65f677b62d6180cc174e06f953f7fe860adf6d1 (diff)
downloadlinux-d710d370c4911e83da5d2bc43d4a2c3b56bd27e7.tar.xz
Merge tag 's390-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik: - Raise minimum supported machine generation to z10, which comes with various cleanups and code simplifications (usercopy/spectre mitigation/etc). - Rework extables and get rid of anonymous out-of-line fixups. - Page table helpers cleanup. Add set_pXd()/set_pte() helper functions. Covert pte_val()/pXd_val() macros to functions. - Optimize kretprobe handling by avoiding extra kprobe on __kretprobe_trampoline. - Add support for CEX8 crypto cards. - Allow to trigger AP bus rescan via writing to /sys/bus/ap/scans. - Add CONFIG_EXPOLINE_EXTERN option to build the kernel without COMDAT group sections which simplifies kpatch support. - Always use the packed stack layout and extend kernel unwinder tests. - Add sanity checks for ftrace code patching. - Add s390dbf debug log for the vfio_ap device driver. - Various virtual vs physical address confusion fixes. - Various small fixes and improvements all over the code. * tag 's390-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (69 commits) s390/test_unwind: add kretprobe tests s390/kprobes: Avoid additional kprobe in kretprobe handling s390: convert ".insn" encoding to instruction names s390: assume stckf is always present s390/nospec: move to single register thunks s390: raise minimum supported machine generation to z10 s390/uaccess: Add copy_from/to_user_key functions s390/nospec: align and size extern thunks s390/nospec: add an option to use thunk-extern s390/nospec: generate single register thunks if possible s390/pci: make zpci_set_irq()/zpci_clear_irq() static s390: remove unused expoline to BC instructions s390/irq: use assignment instead of cast s390/traps: get rid of magic cast for per code s390/traps: get rid of magic cast for program interruption code s390/signal: fix typo in comments s390/asm-offsets: remove unused defines s390/test_unwind: avoid build warning with W=1 s390: remove .fixup section s390/bpf: encode register within extable entry ...
Diffstat (limited to 'arch/s390/mm/extable.c')
-rw-r--r--arch/s390/mm/extable.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/s390/mm/extable.c b/arch/s390/mm/extable.c
new file mode 100644
index 000000000000..8ac8ad2474a0
--- /dev/null
+++ b/arch/s390/mm/extable.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/extable.h>
+#include <linux/errno.h>
+#include <linux/panic.h>
+#include <asm/asm-extable.h>
+#include <asm/extable.h>
+
+const struct exception_table_entry *s390_search_extables(unsigned long addr)
+{
+ const struct exception_table_entry *fixup;
+ size_t num;
+
+ fixup = search_exception_tables(addr);
+ if (fixup)
+ return fixup;
+ num = __stop_amode31_ex_table - __start_amode31_ex_table;
+ return search_extable(__start_amode31_ex_table, num, addr);
+}
+
+static bool ex_handler_fixup(const struct exception_table_entry *ex, struct pt_regs *regs)
+{
+ regs->psw.addr = extable_fixup(ex);
+ return true;
+}
+
+static bool ex_handler_uaccess(const struct exception_table_entry *ex, struct pt_regs *regs)
+{
+ regs->gprs[ex->data] = -EFAULT;
+ regs->psw.addr = extable_fixup(ex);
+ return true;
+}
+
+bool fixup_exception(struct pt_regs *regs)
+{
+ const struct exception_table_entry *ex;
+
+ ex = s390_search_extables(instruction_pointer(regs));
+ if (!ex)
+ return false;
+ switch (ex->type) {
+ case EX_TYPE_FIXUP:
+ return ex_handler_fixup(ex, regs);
+ case EX_TYPE_BPF:
+ return ex_handler_bpf(ex, regs);
+ case EX_TYPE_UACCESS:
+ return ex_handler_uaccess(ex, regs);
+ }
+ panic("invalid exception table entry");
+}