[PATCH] powerpc/fadump: return error when fadump registration fails

From: Michal Suchanek
Date: Thu May 25 2017 - 03:27:58 EST


- log an error message when registration fails and no error code listed
in the switch is returned
- translate the hv error code to posix error code and return it from
fw_register
- return the posix error code from fw_register to the process writing
to sysfs
- return EEXIST on re-registration
- return success on deregistration when fadump is not registered
- return ENODEV when no memory is reserved for fadump

Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
---
arch/powerpc/kernel/fadump.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 2fa582092d42..5a649d76a785 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -398,9 +398,9 @@ static int __init early_fadump_param(char *p)
}
early_param("fadump", early_fadump_param);

-static void register_fw_dump(struct fadump_mem_struct *fdm)
+static int register_fw_dump(struct fadump_mem_struct *fdm)
{
- int rc;
+ int rc, err;
unsigned int wait_time;

pr_debug("Registering for firmware-assisted kernel dump...\n");
@@ -417,7 +417,12 @@ static void register_fw_dump(struct fadump_mem_struct *fdm)

} while (wait_time);

+ err = -EIO;
switch (rc) {
+ default:
+ printk(KERN_ERR "Failed to register firmware-assisted kernel"
+ " dump. Unknown Error(%d).\n", rc);
+ break;
case -1:
printk(KERN_ERR "Failed to register firmware-assisted kernel"
" dump. Hardware Error(%d).\n", rc);
@@ -425,18 +430,22 @@ static void register_fw_dump(struct fadump_mem_struct *fdm)
case -3:
printk(KERN_ERR "Failed to register firmware-assisted kernel"
" dump. Parameter Error(%d).\n", rc);
+ err = -EINVAL;
break;
case -9:
printk(KERN_ERR "firmware-assisted kernel dump is already "
" registered.");
fw_dump.dump_registered = 1;
+ err = -EEXIST;
break;
case 0:
printk(KERN_INFO "firmware-assisted kernel dump registration"
" is successful\n");
fw_dump.dump_registered = 1;
+ err = 0;
break;
}
+ return err;
}

void crash_fadump(struct pt_regs *regs, const char *str)
@@ -977,7 +986,7 @@ static unsigned long init_fadump_header(unsigned long addr)
return addr;
}

-static void register_fadump(void)
+static int register_fadump(void)
{
unsigned long addr;
void *vaddr;
@@ -987,7 +996,7 @@ static void register_fadump(void)
* assisted dump.
*/
if (!fw_dump.reserve_dump_area_size)
- return;
+ return -ENODEV

fadump_setup_crash_memory_ranges();

@@ -1000,7 +1009,7 @@ static void register_fadump(void)
fadump_create_elfcore_headers(vaddr);

/* register the future kernel dump with firmware. */
- register_fw_dump(&fdm);
+ return register_fw_dump(&fdm);
}

static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
@@ -1182,7 +1191,6 @@ static ssize_t fadump_register_store(struct kobject *kobj,
switch (buf[0]) {
case '0':
if (fw_dump.dump_registered == 0) {
- ret = -EINVAL;
goto unlock_out;
}
/* Un-register Firmware-assisted dump */
@@ -1190,11 +1198,11 @@ static ssize_t fadump_register_store(struct kobject *kobj,
break;
case '1':
if (fw_dump.dump_registered == 1) {
- ret = -EINVAL;
+ ret = -EEXIST;
goto unlock_out;
}
/* Register Firmware-assisted dump */
- register_fadump();
+ ret = register_fadump();
break;
default:
ret = -EINVAL;
--
2.10.2