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authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-01 14:41:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-01 14:41:04 -0700
commit5db6db0d400edd8bec274e34960cfa22838e1df5 (patch)
tree3d7934f2eb27a2b72b87eae3c2918cf2e635d814 /arch/alpha/include/asm/extable.h
parent5fab10041b4389b61de7e7a49893190bae686241 (diff)
parent2fefc97b2180518bac923fba3f79fdca1f41dc15 (diff)
Merge branch 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull uaccess unification updates from Al Viro: "This is the uaccess unification pile. It's _not_ the end of uaccess work, but the next batch of that will go into the next cycle. This one mostly takes copy_from_user() and friends out of arch/* and gets the zero-padding behaviour in sync for all architectures. Dealing with the nocache/writethrough mess is for the next cycle; fortunately, that's x86-only. Same for cleanups in iov_iter.c (I am sold on access_ok() in there, BTW; just not in this pile), same for reducing __copy_... callsites, strn*... stuff, etc. - there will be a pile about as large as this one in the next merge window. This one sat in -next for weeks. -3KLoC" * 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (96 commits) HAVE_ARCH_HARDENED_USERCOPY is unconditional now CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional now m32r: switch to RAW_COPY_USER hexagon: switch to RAW_COPY_USER microblaze: switch to RAW_COPY_USER get rid of padding, switch to RAW_COPY_USER ia64: get rid of copy_in_user() ia64: sanitize __access_ok() ia64: get rid of 'segment' argument of __do_{get,put}_user() ia64: get rid of 'segment' argument of __{get,put}_user_check() ia64: add extable.h powerpc: get rid of zeroing, switch to RAW_COPY_USER esas2r: don't open-code memdup_user() alpha: fix stack smashing in old_adjtimex(2) don't open-code kernel_setsockopt() mips: switch to RAW_COPY_USER mips: get rid of tail-zeroing in primitives mips: make copy_from_user() zero tail explicitly mips: clean and reorder the forest of macros... mips: consolidate __invoke_... wrappers ...
Diffstat (limited to 'arch/alpha/include/asm/extable.h')
-rw-r--r--arch/alpha/include/asm/extable.h55
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/extable.h b/arch/alpha/include/asm/extable.h
new file mode 100644
index 000000000000..048e209e524c
--- /dev/null
+++ b/arch/alpha/include/asm/extable.h
@@ -0,0 +1,55 @@
+#ifndef _ASM_EXTABLE_H
+#define _ASM_EXTABLE_H
+
+/*
+ * About the exception table:
+ *
+ * - insn is a 32-bit pc-relative offset from the faulting insn.
+ * - nextinsn is a 16-bit offset off of the faulting instruction
+ * (not off of the *next* instruction as branches are).
+ * - errreg is the register in which to place -EFAULT.
+ * - valreg is the final target register for the load sequence
+ * and will be zeroed.
+ *
+ * Either errreg or valreg may be $31, in which case nothing happens.
+ *
+ * The exception fixup information "just so happens" to be arranged
+ * as in a MEM format instruction. This lets us emit our three
+ * values like so:
+ *
+ * lda valreg, nextinsn(errreg)
+ *
+ */
+
+struct exception_table_entry
+{
+ signed int insn;
+ union exception_fixup {
+ unsigned unit;
+ struct {
+ signed int nextinsn : 16;
+ unsigned int errreg : 5;
+ unsigned int valreg : 5;
+ } bits;
+ } fixup;
+};
+
+/* Returns the new pc */
+#define fixup_exception(map_reg, _fixup, pc) \
+({ \
+ if ((_fixup)->fixup.bits.valreg != 31) \
+ map_reg((_fixup)->fixup.bits.valreg) = 0; \
+ if ((_fixup)->fixup.bits.errreg != 31) \
+ map_reg((_fixup)->fixup.bits.errreg) = -EFAULT; \
+ (pc) + (_fixup)->fixup.bits.nextinsn; \
+})
+
+#define ARCH_HAS_RELATIVE_EXTABLE
+
+#define swap_ex_entry_fixup(a, b, tmp, delta) \
+ do { \
+ (a)->fixup.unit = (b)->fixup.unit; \
+ (b)->fixup.unit = (tmp).fixup.unit; \
+ } while (0)
+
+#endif