Re: [PATCH kvm-unit-tests 1/4] lib: add setjmp header and x86 implementation

[Andrew Jones <drjones@redhat.com>]

On Tue, Dec 15, 2015 at 11:25:35AM +0100, Paolo Bonzini wrote:
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  config/config-i386.mak       |  2 ++
>  config/config-x86-common.mak |  4 +++-
>  config/config-x86_64.mak     |  2 ++
>  lib/setjmp.h                 | 12 ++++++++++++
>  lib/x86/setjmp32.S           | 25 +++++++++++++++++++++++++
>  lib/x86/setjmp64.S           | 27 +++++++++++++++++++++++++++
>  x86/setjmp.c                 | 19 +++++++++++++++++++
>  7 files changed, 90 insertions(+), 1 deletion(-)
>  create mode 100644 lib/setjmp.h
>  create mode 100644 lib/x86/setjmp32.S
>  create mode 100644 lib/x86/setjmp64.S
>  create mode 100644 x86/setjmp.c
> 
> diff --git a/config/config-i386.mak b/config/config-i386.mak
> index 691381c..e353387 100644
> --- a/config/config-i386.mak
> +++ b/config/config-i386.mak
> @@ -3,6 +3,8 @@ bits = 32
>  ldarch = elf32-i386
>  CFLAGS += -I $(KERNELDIR)/include
>  
> +cflatobjs += lib/x86/setjmp32.o
> +
>  tests = $(TEST_DIR)/taskswitch.flat $(TEST_DIR)/taskswitch2.flat \
>  	$(TEST_DIR)/cmpxchg8b.flat
>  
> diff --git a/config/config-x86-common.mak b/config/config-x86-common.mak
> index f64874d..2bb2f46 100644
> --- a/config/config-x86-common.mak
> +++ b/config/config-x86-common.mak
> @@ -34,7 +34,7 @@ tests-common = $(TEST_DIR)/vmexit.flat $(TEST_DIR)/tsc.flat \
>                 $(TEST_DIR)/realmode.flat $(TEST_DIR)/msr.flat \
>                 $(TEST_DIR)/hypercall.flat $(TEST_DIR)/sieve.flat \
>                 $(TEST_DIR)/kvmclock_test.flat  $(TEST_DIR)/eventinj.flat \
> -               $(TEST_DIR)/s3.flat $(TEST_DIR)/pmu.flat \
> +               $(TEST_DIR)/s3.flat $(TEST_DIR)/pmu.flat $(TEST_DIR)/setjmp.flat \
>                 $(TEST_DIR)/tsc_adjust.flat $(TEST_DIR)/asyncpf.flat \
>                 $(TEST_DIR)/init.flat $(TEST_DIR)/smap.flat \
>                 $(TEST_DIR)/hyperv_synic.flat
> @@ -115,6 +115,8 @@ $(TEST_DIR)/memory.elf: $(cstart.o) $(TEST_DIR)/memory.o
>  
>  $(TEST_DIR)/hyperv_synic.elf: $(cstart.o) $(TEST_DIR)/hyperv_synic.o
>  
> +$(TEST_DIR)/setjmp.elf: $(cstart.o) $(TEST_DIR)/setjmp.o
> +
>  arch_clean:
>  	$(RM) $(TEST_DIR)/*.o $(TEST_DIR)/*.flat $(TEST_DIR)/*.elf \
>  	$(TEST_DIR)/.*.d lib/x86/.*.d
> diff --git a/config/config-x86_64.mak b/config/config-x86_64.mak
> index 1764701..d190be8 100644
> --- a/config/config-x86_64.mak
> +++ b/config/config-x86_64.mak
> @@ -3,6 +3,8 @@ bits = 64
>  ldarch = elf64-x86-64
>  CFLAGS += -mno-red-zone
>  
> +cflatobjs += lib/x86/setjmp64.o
> +
>  tests = $(TEST_DIR)/access.flat $(TEST_DIR)/apic.flat \
>  	  $(TEST_DIR)/emulator.flat $(TEST_DIR)/idt_test.flat \
>  	  $(TEST_DIR)/xsave.flat $(TEST_DIR)/rmap_chain.flat \
> diff --git a/lib/setjmp.h b/lib/setjmp.h
> new file mode 100644
> index 0000000..334f466
> --- /dev/null
> +++ b/lib/setjmp.h
> @@ -0,0 +1,12 @@
> +#ifndef LIBCFLAT_SETJMP_H
> +#define LIBCFLAT_SETJMP_H 1
> +
> +typedef struct jmp_buf_tag {
> +	long int regs[8];
> +} jmp_buf[1];
> +
> +extern int setjmp (struct jmp_buf_tag env[1]);
> +extern void longjmp (struct jmp_buf_tag env[1], int val)
> +     __attribute__ ((__noreturn__));
> +
> +#endif /* setjmp.h  */
> diff --git a/lib/x86/setjmp32.S b/lib/x86/setjmp32.S
> new file mode 100644
> index 0000000..b0be7c2
> --- /dev/null
> +++ b/lib/x86/setjmp32.S
> @@ -0,0 +1,25 @@
> +.globl setjmp
> +setjmp:
> +	mov (%esp), %ecx	// get return EIP
> +	mov 4(%esp), %eax	// get jmp_buf
> +	mov %ecx, (%eax)
> +	mov %esp, 4(%eax)
> +	mov %ebp, 8(%eax)
> +	mov %ebx, 12(%eax)
> +	mov %esi, 16(%eax)
> +	mov %edi, 20(%eax)
> +	xor %eax, %eax
> +	ret
> +
> +.globl longjmp
> +longjmp:
> +	mov 8(%esp), %eax	// get return value
> +	mov 4(%esp), %ecx	// get jmp_buf
> +	mov 20(%ecx), %edi
> +	mov 16(%ecx), %esi
> +	mov 12(%ecx), %ebx
> +	mov 8(%ecx), %ebp
> +	mov 4(%ecx), %esp
> +	mov (%ecx), %ecx	// get saved EIP
> +	mov %ecx, (%esp)	// and store it on the stack
> +	ret
> diff --git a/lib/x86/setjmp64.S b/lib/x86/setjmp64.S
> new file mode 100644
> index 0000000..c8ae790
> --- /dev/null
> +++ b/lib/x86/setjmp64.S
> @@ -0,0 +1,27 @@
> +.globl setjmp
> +setjmp:
> +	mov (%rsp), %rsi
> +	mov %rsi, (%rdi)
> +	mov %rsp, 0x8(%rdi)
> +	mov %rbp, 0x10(%rdi)
> +	mov %rbx, 0x18(%rdi)
> +	mov %r12, 0x20(%rdi)
> +	mov %r13, 0x28(%rdi)
> +	mov %r14, 0x30(%rdi)
> +	mov %r15, 0x38(%rdi)
> +	xor %eax, %eax
> +	ret
> +
> +.globl longjmp
> +longjmp:
> +	mov %esi, %eax
> +	mov 0x38(%rdi), %r15
> +	mov 0x30(%rdi), %r14
> +	mov 0x28(%rdi), %r13
> +	mov 0x20(%rdi), %r12
> +	mov 0x18(%rdi), %rbx
> +	mov 0x10(%rdi), %rbp
> +	mov 0x8(%rdi), %rsp
> +	mov (%rdi), %rsi
> +	mov %rsi, (%rsp)
> +	ret
> diff --git a/x86/setjmp.c b/x86/setjmp.c
> new file mode 100644
> index 0000000..46f0d9c
> --- /dev/null
> +++ b/x86/setjmp.c
> @@ -0,0 +1,19 @@
> +#include "stdio.h"
> +#include "setjmp.h"
> +
> +int main()
> +{
> +    volatile int i;
> +    jmp_buf j;
> +
> +    if (setjmp(j) == 0) {
> +	    i = 0;
> +    }
> +    printf("%d\n", i);
> +    if (++i < 10) {
> +	    longjmp(j, 1);
> +    }
> +
> +    printf("done\n");
> +    return 0;

How about making this a "real" test, i.e.

report("longjmp", i == 10);
return report_summary();

I have patches that allow adding timeouts to tests, that I've been
thinking about posting upstream. With those we could add a short
timeout to this one, allowing us to get the FAIL when we loop
forever, as well as when we never loop.

Thanks,
drew


> +}
> -- 
> 2.5.0
> 
> 
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