[Crash-utility] [PATCH] crash: s390x: Add vector register support
Dave Anderson
anderson at redhat.com
Wed Dec 17 21:43:18 UTC 2014
----- Original Message -----
> Hi Dave,
>
> On Wed, 17 Dec 2014 13:33:50 -0500 (EST)
> Dave Anderson <anderson at redhat.com> wrote:
>
> [snip]
>
> > From your example, I presume that this is only applicable to the active
> > tasks?
>
> Correct.
>
> > So instead of using the somewhat-strange "bt -a -A" construct,
> > maybe you could just enter "bt -A" to accomplish the same result?
> >
> > So cmd_bt() would have:
> >
> > case 'A':
> > bt->flags |= BT_SHOW_ALL_REGS; /* FALLTHROUGH */
> > case 'a':
> > active++;
> > break;
> >
> > and the help page would have something like:
> >
> > -a displays the stack traces of the active task on each CPU.",
> > (only applicable to crash dumps)",
> > -A same as -a, but also displays vector registers (S390X only).",
> >
>
> Yes, this makes sense. Here the updated patch:
Hi Mike.
OK this looks good. In cmd_bt() I made the option s390x-only, and touched up the
error message if it's attempted on a live system.
Queued for crash-7.1.0:
https://github.com/crash-utility/crash/commit/e30594ebeacd4a8e0d6c416123f204adf873bf9f
Thanks,
Dave
> ---
> [PATCH] crash: s390x: Add vector register support
>
> This patch adds support for the new s390x vector registers.
> For ELF dumps the registers are taken from the VX ELF notes, for
> s390 dumps the registers are taken from memory. The kernel stores
> a pointer the save area in the CPU lowcores at offset 0x11b0.
>
> This patch also adds the new -A option to the "bt" command. This
> option produces almost the same output as the -a option, but in
> addition also the new vector registers for all active tasks
> are shown. This is done because for normal debugging using "bt -a"
> we do not want to pollute the bt output with the large vector register
> output (512 byte).
>
> The following shows an output example:
>
> crash> bt -A
> PID: 2387 TASK: 1785a5e8 CPU: 0 COMMAND: "bash"
> LOWCORE INFO:
> -psw : 0x0400d00180000000 0x0000000000112aa0
> -function : store_status at 112aa0
> -prefix : 0x1fffc000
> -cpu timer: 0x7ffffff3 0x0066ef81
> -clock cmp: 0x0066ef81 0000000000
> -general registers:
> 000000000000000000 0x0400c00180000000
> ....
> - vector registers:
> 0x404b000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x404b000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
> 0x0000000000000000 0x0000000000000000
>
> Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>
> ---
> defs.h | 1
> help.c | 1
> kernel.c | 5 +--
> netdump.c | 6 +++
> netdump.h | 14 ++++++++
> s390x.c | 100
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 125 insertions(+), 2 deletions(-)
>
> --- a/defs.h
> +++ b/defs.h
> @@ -4966,6 +4966,7 @@ ulong cpu_map_addr(const char *type);
> #define BT_FULL_SYM_SLAB2 (0x400000000000ULL)
> #define BT_EFRAME_TARGET (0x800000000000ULL)
> #define BT_CPUMASK (0x1000000000000ULL)
> +#define BT_SHOW_ALL_REGS (0x2000000000000ULL)
> #define BT_SYMBOL_OFFSET (BT_SYMBOLIC_ARGS)
>
> #define BT_REF_HEXVAL (0x1)
> --- a/help.c
> +++ b/help.c
> @@ -1742,6 +1742,7 @@ char *help_bt[] = {
> " trace of the current context will be displayed.\n",
> " -a displays the stack traces of the active task on each CPU.",
> " (only applicable to crash dumps)",
> +" -A same as -a, but also displays vector registers (S390X only).",
> " -c cpu display the stack trace of the active task on one or more
> CPUs,",
> " which can be specified using the format \"3\", \"1,8,9\",
> \"1-23\",",
> " or \"1,8,9-14\". (only applicable to crash dumps)",
> --- a/kernel.c
> +++ b/kernel.c
> @@ -2003,13 +2003,12 @@ cmd_bt(void)
> if (kt->flags & USE_OLD_BT)
> bt->flags |= BT_OLD_BACK_TRACE;
>
> - while ((c = getopt(argcnt, args, "D:fFI:S:c:aloreEgstTdxR:O")) !=
> EOF) {
> + while ((c = getopt(argcnt, args, "D:fFI:S:c:aAloreEgstTdxR:O")) != EOF) {
> switch (c)
> {
> case 'f':
> bt->flags |= BT_FULL;
> break;
> -
> case 'F':
> if (bt->flags & BT_FULL_SYM_SLAB)
> bt->flags |= BT_FULL_SYM_SLAB2;
> @@ -2158,6 +2157,8 @@ cmd_bt(void)
> }
> break;
>
> + case 'A':
> + bt->flags |= BT_SHOW_ALL_REGS; /* FALLTHROUGH */
> case 'a':
> active++;
> break;
> --- a/netdump.c
> +++ b/netdump.c
> @@ -2086,6 +2086,12 @@ dump_Elf64_Nhdr(Elf64_Off offset, int st
> case NT_S390_PREFIX:
> netdump_print("(NT_S390_PREFIX)\n");
> break;
> + case NT_S390_VXRS_LOW:
> + netdump_print("(NT_S390_VXRS_LOW)\n");
> + break;
> + case NT_S390_VXRS_HIGH:
> + netdump_print("(NT_S390_VXRS_HIGH)\n");
> + break;
> case NT_TASKSTRUCT:
> netdump_print("(NT_TASKSTRUCT)\n");
> if (STRNEQ(buf, "SNAP"))
> --- a/netdump.h
> +++ b/netdump.h
> @@ -169,6 +169,20 @@ struct xen_kdump_data {
> #define NT_S390_PREFIX 0x305
> #endif
>
> +/*
> + * S390 vector registers 0-15 upper half note (16 * u64)
> + */
> +#ifndef NT_S390_VXRS_LOW
> +#define NT_S390_VXRS_LOW 0x309
> +#endif
> +
> +/*
> + * S390 vector registers 16-31 note (16 * u128)
> + */
> +#ifndef NT_S390_VXRS_HIGH
> +#define NT_S390_VXRS_HIGH 0x30a
> +#endif
> +
> #define MAX_KCORE_ELF_HEADER_SIZE (32768)
>
> struct proc_kcore_data {
> --- a/s390x.c
> +++ b/s390x.c
> @@ -41,6 +41,7 @@
> #define KERNEL_STACK_SIZE STACKSIZE() // can be 8192 or 16384
>
> #define LOWCORE_SIZE 8192
> +#define VX_SA_SIZE (32 * 16)
>
> #define S390X_PSW_MASK_PSTATE 0x0001000000000000UL
>
> @@ -72,6 +73,11 @@ struct s390x_nt_fpregset {
> uint64_t fprs[16];
> } __attribute__ ((packed));
>
> +struct s390x_vxrs {
> + uint64_t low;
> + uint64_t high;
> +} __attribute__ ((packed));
> +
> /*
> * s390x CPU info
> */
> @@ -87,6 +93,8 @@ struct s390x_cpu
> uint64_t timer;
> uint64_t todcmp;
> uint32_t todpreg;
> + uint64_t vxrs_low[16];
> + struct s390x_vxrs vxrs_high[16];
> };
>
> /*
> @@ -133,6 +141,27 @@ static unsigned long readmem_ul(unsigned
> }
>
> /*
> + * Print hex data
> + */
> +static void print_hex_buf(void *buf, int len, int cols, char *tag)
> +{
> + int j, first = 1;
> +
> + for (j = 0; j < len; j += 8) {
> + if (j % (cols * 8) == 0) {
> + if (first)
> + first = 0;
> + else
> + fprintf(fp, "\n");
> + fprintf(fp, "%s", tag);
> + }
> + fprintf(fp, "%#018lx ", *((unsigned long *)(buf + j)));
> + }
> + if (len)
> + fprintf(fp, "\n");
> +}
> +
> +/*
> * Initialize member offsets
> */
> static void s390x_offsets_init(void)
> @@ -271,6 +300,16 @@ static void s390x_elf_nt_prefix_add(stru
> memcpy(&cpu->prefix, desc, sizeof(cpu->prefix));
> }
>
> +static void s390x_elf_nt_vxrs_low_add(struct s390x_cpu *cpu, void *desc)
> +{
> + memcpy(&cpu->vxrs_low, desc, sizeof(cpu->vxrs_low));
> +}
> +
> +static void s390x_elf_nt_vxrs_high_add(struct s390x_cpu *cpu, void *desc)
> +{
> + memcpy(&cpu->vxrs_high, desc, sizeof(cpu->vxrs_high));
> +}
> +
> static void *get_elf_note_desc(Elf64_Nhdr *note)
> {
> void *ptr = note;
> @@ -315,6 +354,12 @@ static void s390x_elf_note_add(int elf_c
> case NT_S390_PREFIX:
> s390x_elf_nt_prefix_add(cpu, desc);
> break;
> + case NT_S390_VXRS_LOW:
> + s390x_elf_nt_vxrs_low_add(cpu, desc);
> + break;
> + case NT_S390_VXRS_HIGH:
> + s390x_elf_nt_vxrs_high_add(cpu, desc);
> + break;
> }
> }
>
> @@ -916,6 +961,59 @@ s390x_get_lowcore(struct bt_info *bt, ch
> }
>
> /*
> + * Copy VX registers out of s390x cpu
> + */
> +static void vx_copy(void *buf, struct s390x_cpu *s390x_cpu)
> +{
> + char *_buf = buf;
> + int i;
> +
> + for (i = 0; i < 16; i++) {
> + memcpy(&_buf[i * 16], &s390x_cpu->fprs[i], 8);
> + memcpy(&_buf[i * 16 + 8], &s390x_cpu->vxrs_low[i], 8);
> + }
> + memcpy(&_buf[16 * 16], &s390x_cpu->vxrs_high[0], 16 * 16);
> +}
> +
> +/*
> + * Check if VX registers are available
> + */
> +static int has_vx_regs(char *lowcore)
> +{
> + unsigned long addr = *((uint64_t *)(lowcore + 0x11b0));
> +
> + if (addr == 0 || addr % 1024)
> + return 0;
> + return 1;
> +}
> +
> +/*
> + * Print vector registers for cpu
> + */
> +static void
> +s390x_print_vx_sa(struct bt_info *bt, char *lc)
> +{
> + char vx_sa[VX_SA_SIZE];
> + uint64_t addr;
> +
> + if (!(bt->flags & BT_SHOW_ALL_REGS))
> + return;
> + if (!has_vx_regs(lc))
> + return;
> + if (!s390x_cpu_vec) {
> + /* Pointer to save area */
> + addr = *((uint64_t *)(lc + 0x11b0));
> + readmem(addr, KVADDR, vx_sa, sizeof(vx_sa), "vx_sa",
> + FAULT_ON_ERROR);
> + } else {
> + /* Get data from s390x cpu */
> + vx_copy(vx_sa, s390x_cpu_get(bt));
> + }
> + fprintf(fp, " -vector registers:\n");
> + print_hex_buf(vx_sa, sizeof(vx_sa), 2, " ");
> +}
> +
> +/*
> * Get stack address for interrupt stack using the pcpu array
> */
> static unsigned long get_int_stack_pcpu(char *stack_name, int cpu)
> @@ -1180,9 +1278,11 @@ static void s390x_back_trace_cmd(struct
> if (psw_flags & S390X_PSW_MASK_PSTATE) {
> fprintf(fp,"Task runs in userspace\n");
> s390x_print_lowcore(lowcore,bt,0);
> + s390x_print_vx_sa(bt, lowcore);
> return;
> }
> s390x_print_lowcore(lowcore,bt,1);
> + s390x_print_vx_sa(bt, lowcore);
> fprintf(fp,"\n");
> if (symbol_exists("restart_stack")) {
> get_int_stack("restart_stack",
>
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