From: Janosch Frank <frankja@xxxxxxxxxxxxx> A linker script has a few benefits: - Random data doesn't end up in the binary breaking tests - We can easily define a lowcore and load the snippet from 0x0 instead of 0x4000 which makes asm snippets behave like c snippets - We can easily define an invalid PGM new PSW to ensure an exit on a guest PGM Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230112154548.163021-4-frankja@xxxxxxxxxxxxx Message-Id: <20230112154548.163021-4-frankja@xxxxxxxxxxxxx> --- s390x/Makefile | 5 +++-- lib/s390x/snippet.h | 3 +-- s390x/snippets/asm/flat.lds | 41 +++++++++++++++++++++++++++++++++++++ s390x/mvpg-sie.c | 2 +- s390x/pv-diags.c | 6 +++--- 5 files changed, 49 insertions(+), 8 deletions(-) create mode 100644 s390x/snippets/asm/flat.lds diff --git a/s390x/Makefile b/s390x/Makefile index 52a9d821..97a61611 100644 --- a/s390x/Makefile +++ b/s390x/Makefile @@ -136,7 +136,8 @@ $(SNIPPET_DIR)/c/%.o: $(SNIPPET_DIR)/c/%.c $(asm-offsets) $(CC) $(CFLAGS) -c -nostdlib -o $@ $< $(SNIPPET_DIR)/asm/%.gbin: $(SNIPPET_DIR)/asm/%.o - $(OBJCOPY) -O binary -j ".rodata" -j ".text" -j ".data" -j ".bss" --set-section-flags .bss=alloc,load,contents $(patsubst %.gbin,%.o,$@) $@ + $(CC) $(LDFLAGS) -o $@ -T $(SRCDIR)/s390x/snippets/asm/flat.lds $< + $(OBJCOPY) -O binary -j ".rodata" -j ".lowcore" -j ".text" -j ".data" -j ".bss" --set-section-flags .bss=alloc,load,contents $@ $@ truncate -s '%4096' $@ $(SNIPPET_DIR)/c/%.gbin: $(SNIPPET_DIR)/c/%.o $(snippet_lib) $(FLATLIBS) @@ -145,7 +146,7 @@ $(SNIPPET_DIR)/c/%.gbin: $(SNIPPET_DIR)/c/%.o $(snippet_lib) $(FLATLIBS) truncate -s '%4096' $@ $(SNIPPET_DIR)/asm/%.hdr: $(SNIPPET_DIR)/asm/%.gbin $(HOST_KEY_DOCUMENT) - $(GEN_SE_HEADER) -k $(HOST_KEY_DOCUMENT) -c $<,0x4000,0x00000000000000420000000000000000 --psw-addr 0x4000 -o $@ + $(GEN_SE_HEADER) -k $(HOST_KEY_DOCUMENT) -c $<,0x0,0x00000000000000420000000000000000 --psw-addr 0x4000 -o $@ $(SNIPPET_DIR)/c/%.hdr: $(SNIPPET_DIR)/c/%.gbin $(HOST_KEY_DOCUMENT) $(GEN_SE_HEADER) -k $(HOST_KEY_DOCUMENT) -c $<,0x0,0x00000000000000420000000000000000 --psw-addr 0x4000 -o $@ diff --git a/lib/s390x/snippet.h b/lib/s390x/snippet.h index b17b2a4c..57045994 100644 --- a/lib/s390x/snippet.h +++ b/lib/s390x/snippet.h @@ -32,8 +32,7 @@ #define SNIPPET_PV_TWEAK0 0x42UL #define SNIPPET_PV_TWEAK1 0UL -#define SNIPPET_OFF_C 0 -#define SNIPPET_OFF_ASM 0x4000 +#define SNIPPET_UNPACK_OFF 0 /* diff --git a/s390x/snippets/asm/flat.lds b/s390x/snippets/asm/flat.lds new file mode 100644 index 00000000..ab0031ac --- /dev/null +++ b/s390x/snippets/asm/flat.lds @@ -0,0 +1,41 @@ +SECTIONS +{ + .lowcore : { + /* + * Initial short psw for disk boot, with 31 bit addressing for + * non z/Arch environment compatibility and the instruction + * address 0x4000. + */ + . = 0; + LONG(0x00080000) + LONG(0x80004000) + /* Restart new PSW for booting via PSW restart. */ + . = 0x1a0; + QUAD(0x0000000180000000) + QUAD(0x0000000000004000) + /* + * Invalid PGM new PSW so we hopefully get a code 8 + * intercept on a PGM + */ + . = 0x1d0; + QUAD(0x0008000000000000) + QUAD(0x0000000000000001) + } + . = 0x4000; + /* Start text 0x4000 */ + .text : { + *(.text) + *(.text.*) + } + . = ALIGN(16); + etext = .; + /* End text */ + /* Start data */ + .data : { + *(.data) + *(.data.rel*) + } + . = ALIGN(16); + .rodata : { *(.rodata) *(.rodata.*) } + /* End data */ +} diff --git a/s390x/mvpg-sie.c b/s390x/mvpg-sie.c index 46a2edb6..99f4859b 100644 --- a/s390x/mvpg-sie.c +++ b/s390x/mvpg-sie.c @@ -87,7 +87,7 @@ static void setup_guest(void) snippet_setup_guest(&vm, false); snippet_init(&vm, SNIPPET_NAME_START(c, mvpg_snippet), - SNIPPET_LEN(c, mvpg_snippet), SNIPPET_OFF_C); + SNIPPET_LEN(c, mvpg_snippet), SNIPPET_UNPACK_OFF); /* Enable MVPG interpretation as we want to test KVM and not ourselves */ vm.sblk->eca = ECA_MVPGI; diff --git a/s390x/pv-diags.c b/s390x/pv-diags.c index 9ced68c7..5165937a 100644 --- a/s390x/pv-diags.c +++ b/s390x/pv-diags.c @@ -28,7 +28,7 @@ static void test_diag_500(void) snippet_pv_init(&vm, SNIPPET_NAME_START(asm, snippet_pv_diag_500), SNIPPET_HDR_START(asm, snippet_pv_diag_500), - size_gbin, size_hdr, SNIPPET_OFF_ASM); + size_gbin, size_hdr, SNIPPET_UNPACK_OFF); sie(&vm); report(vm.sblk->icptcode == ICPT_PV_INSTR && vm.sblk->ipa == 0x8302 && @@ -83,7 +83,7 @@ static void test_diag_288(void) snippet_pv_init(&vm, SNIPPET_NAME_START(asm, snippet_pv_diag_288), SNIPPET_HDR_START(asm, snippet_pv_diag_288), - size_gbin, size_hdr, SNIPPET_OFF_ASM); + size_gbin, size_hdr, SNIPPET_UNPACK_OFF); sie(&vm); report(vm.sblk->icptcode == ICPT_PV_INSTR && vm.sblk->ipa == 0x8302 && @@ -124,7 +124,7 @@ static void test_diag_yield(void) snippet_pv_init(&vm, SNIPPET_NAME_START(asm, snippet_pv_diag_yield), SNIPPET_HDR_START(asm, snippet_pv_diag_yield), - size_gbin, size_hdr, SNIPPET_OFF_ASM); + size_gbin, size_hdr, SNIPPET_UNPACK_OFF); /* 0x44 */ report_prefix_push("0x44"); -- 2.39.1
