[Crash-utility] Re: [RFC]Patch to accomodate cpu_pda changes in x86_64 kernels
Dave Anderson
anderson at redhat.com
Tue Jan 31 14:11:36 UTC 2006
Rachita Kothiyal wrote:
> Hi Dave,
>
> Following the changes in the way cpu_pda is accessed
> on x86_64 kernels, running crash to analyse kdump based
> crash dumps gave the following error:
>
> crash: cannot resolve "cpu_pda"
>
> The following patch fixes this. Kindly review.
>
Hi Rachita,
Thanks for handling this. I haven't looked at this, and correct me
if I'm wrong, but the kernel (what version exactly?) now has contains
a _cpu_pda[NR_CPUS] array containing pointers to the actual per-cpu
x8664_pda structures. Given that, there's really no reason to GETBUF()
the storage location of the single per-cpu pointer. When I compile
with "make Warn", I get this:
# make Warn
...
cc -c -g -DX86_64 x86_64.c -Wall -Wstrict-prototypes -Wmissing-prototypes -Werror
x86_64.c: In function `x86_64_cpu_pda_init':
x86_64.c:389: warning: assignment from incompatible pointer type
x86_64.c:391: warning: assignment makes integer from pointer without a cast
x86_64.c: In function `x86_64_get_smp_cpus':
x86_64.c:2763: warning: assignment from incompatible pointer type
x86_64.c:2765: warning: assignment makes integer from pointer without a cast
make[3]: *** [x86_64.o] Error 1
make[2]: *** [gdb] Error 2
make[1]: *** [gdb_merge] Error 2
make: *** [Warn] Error 2
#
which is complaining about the cpu_pda pointer and its use:
389 cpu_pda_addr = GETBUF(sizeof(unsigned long));
390 for (i = cpus = 0; i < nr_pda; i++) {
391 *cpu_pda_addr = NULL;
2763 cpu_pda_addr = GETBUF(sizeof(unsigned long));
2764 for (i = cpus = 0; i < nr_pda; i++) {
2765 *cpu_pda_addr = NULL;
I'd just make cpu_pda_addr a ulong stack variable, zero it out on lines
389 and 2765, and change the _CPU_PDA_READ() macro to look
like this:
#define _CPU_PDA_READ(CPU, BUFFER) \
((STRNEQ("_cpu_pda", closest_symbol((symbol_value("_cpu_pda") + \
((CPU) * sizeof(unsigned long)))))) && \
(readmem(symbol_value("_cpu_pda") + ((CPU) * sizeof(unsigned long)),\
KVADDR, &cpu_pda_addr, sizeof(unsigned long), "_cpu_pda addr", \
FAULT_ON_ERROR)) && \
(readmem(cpu_pda_addr , \
KVADDR, (BUFFER), SIZE(x8664_pda), "cpu_pda entry", \
FAULT_ON_ERROR)))
Unless I'm missing something, that simplifies things and should work
just fine. But I can't test it here other than to verify that it's
backwards compatible. Can you verify that?
Thanks again,
Dave
>
> Thanks
> Rachita
>
> Signed-off-by: Rachita Kothiyal <rachita at in.ibm.com>
> ---
>
> defs.h | 10 ++++
> x86_64.c | 139 ++++++++++++++++++++++++++++++++++++++++++++-------------------
> 2 files changed, 108 insertions(+), 41 deletions(-)
>
> diff -puN x86_64.c~crash-fix-cpu-pda x86_64.c
> --- crash-4.0-2.19/x86_64.c~crash-fix-cpu-pda 2006-01-31 17:21:35.430960480 +0530
> +++ crash-4.0-2.19-rachita/x86_64.c 2006-01-31 17:23:44.893279216 +0530
> @@ -367,7 +367,7 @@ x86_64_cpu_pda_init(void)
> {
> int i, cpus, nr_pda, cpunumber;
> char *cpu_pda_buf;
> - ulong level4_pgt, data_offset;
> + ulong level4_pgt, data_offset, *cpu_pda_addr;
> struct syment *sp, *nsp;
> ulong offset, istacksize;
>
> @@ -383,36 +383,68 @@ x86_64_cpu_pda_init(void)
>
> cpu_pda_buf = GETBUF(SIZE(x8664_pda));
>
> - if (!(nr_pda = get_array_length("cpu_pda", NULL, 0)))
> - nr_pda = NR_CPUS;
> -
> - for (i = cpus = 0; i < nr_pda; i++) {
> - if (!CPU_PDA_READ(i, cpu_pda_buf))
> - break;
> - if (VALID_MEMBER(x8664_pda_level4_pgt)) {
> - level4_pgt = ULONG(cpu_pda_buf + OFFSET(x8664_pda_level4_pgt));
> - if (!VALID_LEVEL4_PGT_ADDR(level4_pgt))
> + if (symbol_exists("_cpu_pda")) {
> + if (!(nr_pda = get_array_length("_cpu_pda", NULL, 0)))
> + nr_pda = NR_CPUS;
> + cpu_pda_addr = GETBUF(sizeof(unsigned long));
> + for (i = cpus = 0; i < nr_pda; i++) {
> + *cpu_pda_addr = NULL;
> + if (!_CPU_PDA_READ(i, cpu_pda_buf))
> break;
> - }
> - cpunumber = INT(cpu_pda_buf + OFFSET(x8664_pda_cpunumber));
> - if (cpunumber != cpus)
> - break;
> - cpus++;
>
> - if (VALID_MEMBER(x8664_pda_data_offset)) {
> - data_offset = ULONG(cpu_pda_buf +
> - OFFSET(x8664_pda_data_offset));
> - kt->__per_cpu_offset[i] = data_offset;
> - kt->flags |= PER_CPU_OFF;
> - } else
> - data_offset = 0;
> + if (VALID_MEMBER(x8664_pda_level4_pgt)) {
> + level4_pgt = ULONG(cpu_pda_buf + OFFSET(x8664_pda_level4_pgt));
> + if (!VALID_LEVEL4_PGT_ADDR(level4_pgt))
> + break;
> + }
> + cpunumber = INT(cpu_pda_buf + OFFSET(x8664_pda_cpunumber));
> + if (cpunumber != cpus)
> + break;
> + cpus++;
>
> - machdep->machspec->stkinfo.ibase[i] = ULONG(cpu_pda_buf +
> - OFFSET(x8664_pda_irqstackptr));
> + if (VALID_MEMBER(x8664_pda_data_offset)) {
> + data_offset = ULONG(cpu_pda_buf +
> + OFFSET(x8664_pda_data_offset));
> + kt->__per_cpu_offset[i] = data_offset;
> + kt->flags |= PER_CPU_OFF;
> + } else
> + data_offset = 0;
> + machdep->machspec->stkinfo.ibase[i] = ULONG(cpu_pda_buf +
> + OFFSET(x8664_pda_irqstackptr));
> + if (CRASHDEBUG(2))
> + fprintf(fp, "CPU%d: level4_pgt: %lx data_offset: %lx\n",
> + i, level4_pgt, data_offset);
> + }
> + FREEBUF(cpu_pda_addr);
> + } else if (symbol_exists("cpu_pda")) {
> + if (!(nr_pda = get_array_length("cpu_pda", NULL, 0)))
> + nr_pda = NR_CPUS;
> + for (i = cpus = 0; i < nr_pda; i++) {
> + if (!CPU_PDA_READ(i, cpu_pda_buf))
> + break;
> + if (VALID_MEMBER(x8664_pda_level4_pgt)) {
> + level4_pgt = ULONG(cpu_pda_buf + OFFSET(x8664_pda_level4_pgt));
> + if (!VALID_LEVEL4_PGT_ADDR(level4_pgt))
> + break;
> + }
> + cpunumber = INT(cpu_pda_buf + OFFSET(x8664_pda_cpunumber));
> + if (cpunumber != cpus)
> + break;
> + cpus++;
>
> - if (CRASHDEBUG(2))
> - fprintf(fp, "CPU%d: level4_pgt: %lx data_offset: %lx\n",
> - i, level4_pgt, data_offset);
> + if (VALID_MEMBER(x8664_pda_data_offset)) {
> + data_offset = ULONG(cpu_pda_buf +
> + OFFSET(x8664_pda_data_offset));
> + kt->__per_cpu_offset[i] = data_offset;
> + kt->flags |= PER_CPU_OFF;
> + } else
> + data_offset = 0;
> + machdep->machspec->stkinfo.ibase[i] = ULONG(cpu_pda_buf +
> + OFFSET(x8664_pda_irqstackptr));
> + if (CRASHDEBUG(2))
> + fprintf(fp, "CPU%d: level4_pgt: %lx data_offset: %lx\n",
> + i, level4_pgt, data_offset);
> + }
> }
>
>
> @@ -2718,29 +2750,51 @@ x86_64_get_smp_cpus(void)
> {
> int i, cpus, nr_pda, cpunumber;
> char *cpu_pda_buf;
> - ulong level4_pgt;
> + ulong level4_pgt, *cpu_pda_addr;
>
> if (!VALID_STRUCT(x8664_pda))
> return 1;
>
> cpu_pda_buf = GETBUF(SIZE(x8664_pda));
>
> - if (!(nr_pda = get_array_length("cpu_pda", NULL, 0)))
> - nr_pda = NR_CPUS;
> + if (symbol_exists("_cpu_pda")){
> + if (!(nr_pda = get_array_length("_cpu_pda", NULL, 0)))
> + nr_pda = NR_CPUS;
> + cpu_pda_addr = GETBUF(sizeof(unsigned long));
> + for (i = cpus = 0; i < nr_pda; i++) {
> + *cpu_pda_addr = NULL;
> + if (!_CPU_PDA_READ(i, cpu_pda_buf))
> + break;
>
> - for (i = cpus = 0; i < nr_pda; i++) {
> - if (!CPU_PDA_READ(i, cpu_pda_buf))
> - break;
> + if (VALID_MEMBER(x8664_pda_level4_pgt)) {
> + level4_pgt = ULONG(cpu_pda_buf + OFFSET(x8664_pda_level4_pgt));
> + if (!VALID_LEVEL4_PGT_ADDR(level4_pgt))
> + break;
> + }
> + cpunumber = INT(cpu_pda_buf + OFFSET(x8664_pda_cpunumber));
> + if (cpunumber != cpus)
> + break;
> + cpus++;
> + }
> + FREEBUF(cpu_pda_addr);
> + }
> + else if (symbol_exists("cpu_pda")){
> + if (!(nr_pda = get_array_length("cpu_pda", NULL, 0)))
> + nr_pda = NR_CPUS;
> + for (i = cpus = 0; i < nr_pda; i++) {
> + if (!CPU_PDA_READ(i, cpu_pda_buf))
> + break;
>
> - if (VALID_MEMBER(x8664_pda_level4_pgt)) {
> - level4_pgt = ULONG(cpu_pda_buf + OFFSET(x8664_pda_level4_pgt));
> - if (!VALID_LEVEL4_PGT_ADDR(level4_pgt))
> + if (VALID_MEMBER(x8664_pda_level4_pgt)) {
> + level4_pgt = ULONG(cpu_pda_buf + OFFSET(x8664_pda_level4_pgt));
> + if (!VALID_LEVEL4_PGT_ADDR(level4_pgt))
> + break;
> + }
> + cpunumber = INT(cpu_pda_buf + OFFSET(x8664_pda_cpunumber));
> + if (cpunumber != cpus)
> break;
> + cpus++;
> }
> - cpunumber = INT(cpu_pda_buf + OFFSET(x8664_pda_cpunumber));
> - if (cpunumber != cpus)
> - break;
> - cpus++;
> }
>
> FREEBUF(cpu_pda_buf);
> @@ -2828,7 +2882,10 @@ x86_64_display_cpu_data(void)
> boot_cpu = TRUE;
> cpus = 1;
> }
> - cpu_pda = symbol_value("cpu_pda");
> + if (symbol_exists("_cpu_pda"))
> + cpu_pda = symbol_value("_cpu_pda");
> + else if (symbol_exists("cpu_pda"))
> + cpu_pda = symbol_value("cpu_pda");
>
> for (cpu = 0; cpu < cpus; cpu++) {
> if (boot_cpu)
> diff -puN defs.h~crash-fix-cpu-pda defs.h
> --- crash-4.0-2.19/defs.h~crash-fix-cpu-pda 2006-01-31 17:25:59.479818952 +0530
> +++ crash-4.0-2.19-rachita/defs.h 2006-01-31 17:26:23.969096016 +0530
> @@ -1840,6 +1840,16 @@ struct load_module {
>
> #define PAGEBASE(X) (((ulong)(X)) & (ulong)machdep->pagemask)
>
> +#define _CPU_PDA_READ(CPU, BUFFER) \
> + ((STRNEQ("_cpu_pda", closest_symbol((symbol_value("_cpu_pda") + \
> + ((CPU) * sizeof(unsigned long)))))) && \
> + (readmem(symbol_value("_cpu_pda") + ((CPU) * sizeof(unsigned long)),\
> + KVADDR, cpu_pda_addr, sizeof(unsigned long), "_cpu_pda addr", \
> + FAULT_ON_ERROR)) && \
> + (readmem(*cpu_pda_addr , \
> + KVADDR, (BUFFER), SIZE(x8664_pda), "cpu_pda entry", \
> + FAULT_ON_ERROR)))
> +
> #define CPU_PDA_READ(CPU, BUFFER) \
> (STRNEQ("cpu_pda", closest_symbol((symbol_value("cpu_pda") + \
> ((CPU) * SIZE(x8664_pda))))) && \
> _
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