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powerpc/xmon: Add address lookup for percpu symbols

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Currently, in xmon, there is no obvious way to get an address for a
percpu symbol for a particular cpu. Having such an ability would be
good for debugging the system when percpu variables got involved.

Therefore, this patch introduces a new xmon command "lp" to lookup the
address for percpu symbols. Usage of "lp" is similar to "ls", except
that we could add a cpu number to choose the variable of which cpu we
want to lookup. If no cpu number is given, lookup for current cpu.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Boqun Feng 2016-11-22 17:20:09 +08:00 committed by Michael Ellerman
parent 646dbe40fa
commit 302c7b0c4f
1 changed files with 32 additions and 1 deletions
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33
arch/powerpc/xmon/xmon.c
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@ -56,6 +56,7 @@
#include <asm/opal.h>
#include <asm/firmware.h>
#include <asm/code-patching.h>
#include <asm/sections.h>
#ifdef CONFIG_PPC64
#include <asm/hvcall.h>
@ -244,6 +245,7 @@ Commands:\n\
f flush cache\n\
la lookup symbol+offset of specified address\n\
ls lookup address of specified symbol\n\
lp s [#] lookup address of percpu symbol s for current cpu, or cpu #\n\
m examine/change memory\n\
mm move a block of memory\n\
ms set a block of memory\n\
@ -3352,7 +3354,8 @@ static void
symbol_lookup(void)
{
int type = inchar();
unsigned long addr;
unsigned long addr, cpu;
void __percpu *ptr = NULL;
static char tmp[64];
switch (type) {
@ -3373,6 +3376,34 @@ symbol_lookup(void)
printf("Symbol '%s' not found.\n", tmp);
sync();
}
catch_memory_errors = 0;
termch = 0;
break;
case 'p':
getstring(tmp, 64);
if (setjmp(bus_error_jmp) == 0) {
catch_memory_errors = 1;
sync();
ptr = (void __percpu *)kallsyms_lookup_name(tmp);
sync();
}
if (ptr &&
ptr >= (void __percpu *)__per_cpu_start &&
ptr < (void __percpu *)__per_cpu_end)
{
if (scanhex(&cpu) && cpu < num_possible_cpus()) {
addr = (unsigned long)per_cpu_ptr(ptr, cpu);
} else {
cpu = raw_smp_processor_id();
addr = (unsigned long)this_cpu_ptr(ptr);
}
printf("%s for cpu 0x%lx: %lx\n", tmp, cpu, addr);
} else {
printf("Percpu symbol '%s' not found.\n", tmp);
}
catch_memory_errors = 0;
termch = 0;
break;