Commit 302c7b0c authored by Boqun Feng's avatar Boqun Feng Committed by Michael Ellerman
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powerpc/xmon: Add address lookup for percpu symbols 



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: default avatarBoqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 646dbe40

arch/powerpc/xmon/xmon.c

+32 −1
Original line number Diff line number Diff line
@@ -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;

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