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authorJeff Dike <jdike@addtoit.com>2006-09-25 23:32:59 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 08:49:05 -0700
commit13c06be399902c9ebda08e092edb1614bb4a3761 (patch)
treec67134cfb7efd23ab7017fde32657fa3a7e58154 /arch/um/sys-x86_64
parentc5c6ba4e08ab9c9e390a0f3a7d9a5c332f5cc6ef (diff)
downloadop-kernel-dev-13c06be399902c9ebda08e092edb1614bb4a3761.zip
op-kernel-dev-13c06be399902c9ebda08e092edb1614bb4a3761.tar.gz
[PATCH] uml: Use klibc setjmp/longjmp
This patch adds an implementation of setjmp and longjmp to UML, allowing access to the inside of a jmpbuf without needing the access macros formerly provided by libc. The implementation is stolen from klibc. I copy the relevant files into arch/um. I have another patch which avoids the copying, but requires klibc be in the tree. setjmp and longjmp users required some tweaking. Includes of <setjmp.h> were removed and includes of the UML longjmp.h were added where necessary. There are also replacements of siglongjmp with UML_LONGJMP which I somehow missed earlier. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/sys-x86_64')
-rw-r--r--arch/um/sys-x86_64/Makefile4
-rw-r--r--arch/um/sys-x86_64/setjmp.S54
2 files changed, 56 insertions, 2 deletions
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index c19794d..f41768b 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -5,8 +5,8 @@
#
obj-y = bugs.o delay.o fault.o ldt.o mem.o ptrace.o ptrace_user.o \
- sigcontext.o signal.o syscalls.o syscall_table.o sysrq.o ksyms.o \
- tls.o
+ setjmp.o sigcontext.o signal.o syscalls.o syscall_table.o sysrq.o \
+ ksyms.o tls.o
obj-$(CONFIG_MODE_SKAS) += stub.o stub_segv.o
obj-$(CONFIG_MODULES) += um_module.o
diff --git a/arch/um/sys-x86_64/setjmp.S b/arch/um/sys-x86_64/setjmp.S
new file mode 100644
index 0000000..45f547b
--- /dev/null
+++ b/arch/um/sys-x86_64/setjmp.S
@@ -0,0 +1,54 @@
+#
+# arch/x86_64/setjmp.S
+#
+# setjmp/longjmp for the x86-64 architecture
+#
+
+#
+# The jmp_buf is assumed to contain the following, in order:
+# %rbx
+# %rsp (post-return)
+# %rbp
+# %r12
+# %r13
+# %r14
+# %r15
+# <return address>
+#
+
+ .text
+ .align 4
+ .globl setjmp
+ .type setjmp, @function
+setjmp:
+ pop %rsi # Return address, and adjust the stack
+ xorl %eax,%eax # Return value
+ movq %rbx,(%rdi)
+ movq %rsp,8(%rdi) # Post-return %rsp!
+ push %rsi # Make the call/return stack happy
+ movq %rbp,16(%rdi)
+ movq %r12,24(%rdi)
+ movq %r13,32(%rdi)
+ movq %r14,40(%rdi)
+ movq %r15,48(%rdi)
+ movq %rsi,56(%rdi) # Return address
+ ret
+
+ .size setjmp,.-setjmp
+
+ .text
+ .align 4
+ .globl longjmp
+ .type longjmp, @function
+longjmp:
+ movl %esi,%eax # Return value (int)
+ movq (%rdi),%rbx
+ movq 8(%rdi),%rsp
+ movq 16(%rdi),%rbp
+ movq 24(%rdi),%r12
+ movq 32(%rdi),%r13
+ movq 40(%rdi),%r14
+ movq 48(%rdi),%r15
+ jmp *56(%rdi)
+
+ .size longjmp,.-longjmp
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