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authorBoqun Feng <boqun.feng@gmail.com>2016-11-22 12:20:09 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2018-08-10 15:12:35 +0300
commit302c7b0c4ff5aed585419603f835dee30207e5d5 (patch)
tree509bc52c839c0ebdafd7eef8a52d11cfa092a31b /arch/powerpc
parent646dbe40fa2a54118975792fa9b98cefac7d232e (diff)
downloadlinux-302c7b0c4ff5aed585419603f835dee30207e5d5.tar.xz
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: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/xmon/xmon.c33
1 files changed, 32 insertions, 1 deletions
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index b7dd683b0470..7c4aa5b00302 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -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) {
@@ -3376,6 +3379,34 @@ symbol_lookup(void)
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;
}
}