# # kbuild file for usr/ - including initramfs image # klibcdirs:; PHONY += klibcdirs suffix_y = $(subst $\",,$(CONFIG_INITRAMFS_COMPRESSION)) datafile_y = initramfs_data.cpio$(suffix_y) AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/$(datafile_y)" # Generate builtin.o based on initramfs_data.o obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o # initramfs_data.o contains the compressed initramfs_data.cpio image. # The image is included using .incbin, a dependency which is not # tracked automatically. $(obj)/initramfs_data.o: $(obj)/$(datafile_y) FORCE ##### # Generate the initramfs cpio archive hostprogs-y := gen_init_cpio initramfs := $(CONFIG_SHELL) $(srctree)/scripts/gen_initramfs_list.sh ramfs-input := $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \ $(shell echo $(CONFIG_INITRAMFS_SOURCE)),-d) ramfs-args := \ $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \ $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) # .initramfs_data.cpio.d is used to identify all files included # in initramfs and to detect if any files are added/removed. # Removed files are identified by directory timestamp being updated # The dependency list is generated by gen_initramfs.sh -l ifneq ($(wildcard $(obj)/.initramfs_data.cpio.d),) include $(obj)/.initramfs_data.cpio.d endif quiet_cmd_initfs = GEN $@ cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input) targets := $(datafile_y) # do not try to update files included in initramfs $(deps_initramfs): ; $(deps_initramfs): klibcdirs # We rebuild initramfs_data.cpio if: # 1) Any included file is newer then initramfs_data.cpio # 2) There are changes in which files are included (added or deleted) # 3) If gen_init_cpio are newer than initramfs_data.cpio # 4) arguments to gen_initramfs.sh changes $(obj)/$(datafile_y): $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs $(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.d $(call if_changed,initfs) 86a1c06cb6cc9ac87664a0c9d3413d51'>commitdiff
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authorLinus Torvalds <torvalds@linux-foundation.org>2016-08-08 13:02:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-08-08 13:02:01 -0700
commit1bd4403d86a1c06cb6cc9ac87664a0c9d3413d51 (patch)
treef1a8f1572b452abcf9237c28859dac4c9bd31fa7 /arch/ia64/include/asm
parent574673c231a5fad1560249cc3a598907acb36cf9 (diff)
unsafe_[get|put]_user: change interface to use a error target label
When I initially added the unsafe_[get|put]_user() helpers in commit 5b24a7a2aa20 ("Add 'unsafe' user access functions for batched accesses"), I made the mistake of modeling the interface on our traditional __[get|put]_user() functions, which return zero on success, or -EFAULT on failure. That interface is fairly easy to use, but it's actually fairly nasty for good code generation, since it essentially forces the caller to check the error value for each access. In particular, since the error handling is already internally implemented with an exception handler, and we already use "asm goto" for various other things, we could fairly easily make the error cases just jump directly to an error label instead, and avoid the need for explicit checking after each operation. So switch the interface to pass in an error label, rather than checking the error value in the caller. Best do it now before we start growing more users (the signal handling code in particular would be a good place to use the new interface). So rather than if (unsafe_get_user(x, ptr)) ... handle error .. the interface is now unsafe_get_user(x, ptr, label); where an error during the user mode fetch will now just cause a jump to 'label' in the caller. Right now the actual _implementation_ of this all still ends up being a "if (err) goto label", and does not take advantage of any exception label tricks, but for "unsafe_put_user()" in particular it should be fairly straightforward to convert to using the exception table model. Note that "unsafe_get_user()" is much harder to convert to a clever exception table model, because current versions of gcc do not allow the use of "asm goto" (for the exception) with output values (for the actual value to be fetched). But that is hopefully not a limitation in the long term. [ Also note that it might be a good idea to switch unsafe_get_user() to actually _return_ the value it fetches from user space, but this commit only changes the error handling semantics ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/ia64/include/asm')