[PATCH 5.4 068/411] powerpc/fadump: Fix fadump to work with a different endian capture kernel

Greg Kroah-Hartman
2022-06-13T11:06:36Z

From: Hari Bathini <hbathini@linux.ibm.com>

[ Upstream commit b74196af372f7cb4902179009265fe63ac81824f ]

Dump capture would fail if capture kernel is not of the endianess as the
production kernel, because the in-memory data structure (struct
opal_fadump_mem_struct) shared across production kernel and capture
kernel assumes the same endianess for both the kernels, which doesn't
have to be true always. Fix it by having a well-defined endianess for
struct opal_fadump_mem_struct.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161902744901.86147.14719228311655123526.stgit@hbathini
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/platforms/powernv/opal-fadump.c | 94 +++++++++++---------
arch/powerpc/platforms/powernv/opal-fadump.h | 10 +--
2 files changed, 57 insertions(+), 47 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c
index d361d37d975f..f5cea068f0bd 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.c
+++ b/arch/powerpc/platforms/powernv/opal-fadump.c
@@ -60,7 +60,7 @@ void __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node)
addr = be64_to_cpu(addr);
pr_debug("Kernel metadata addr: %llx\n", addr);
opal_fdm_active = (void *)addr;
- if (opal_fdm_active->registered_regions == 0)
+ if (be16_to_cpu(opal_fdm_active->registered_regions) == 0)
return;

ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_BOOT_MEM, &addr);
@@ -95,17 +95,17 @@ static int opal_fadump_unregister(struct fw_dump *fadump_conf);
static void opal_fadump_update_config(struct fw_dump *fadump_conf,
const struct opal_fadump_mem_struct *fdm)
{
- pr_debug("Boot memory regions count: %d\n", fdm->region_cnt);
+ pr_debug("Boot memory regions count: %d\n", be16_to_cpu(fdm->region_cnt));

/*
* The destination address of the first boot memory region is the
* destination address of boot memory regions.
*/
- fadump_conf->boot_mem_dest_addr = fdm->rgn[0].dest;
+ fadump_conf->boot_mem_dest_addr = be64_to_cpu(fdm->rgn[0].dest);
pr_debug("Destination address of boot memory regions: %#016llx\n",
fadump_conf->boot_mem_dest_addr);

- fadump_conf->fadumphdr_addr = fdm->fadumphdr_addr;
+ fadump_conf->fadumphdr_addr = be64_to_cpu(fdm->fadumphdr_addr);
}

/*
@@ -126,9 +126,9 @@ static void opal_fadump_get_config(struct fw_dump *fadump_conf,
fadump_conf->boot_memory_size = 0;

pr_debug("Boot memory regions:\n");
- for (i = 0; i < fdm->region_cnt; i++) {
- base = fdm->rgn[i].src;
- size = fdm->rgn[i].size;
+ for (i = 0; i < be16_to_cpu(fdm->region_cnt); i++) {
+ base = be64_to_cpu(fdm->rgn[i].src);
+ size = be64_to_cpu(fdm->rgn[i].size);
pr_debug("\t[%03d] base: 0x%lx, size: 0x%lx\n", i, base, size);

fadump_conf->boot_mem_addr[i] = base;
@@ -143,7 +143,7 @@ static void opal_fadump_get_config(struct fw_dump *fadump_conf,
* Start address of reserve dump area (permanent reservation) for
* re-registering FADump after dump capture.
*/
- fadump_conf->reserve_dump_area_start = fdm->rgn[0].dest;
+ fadump_conf->reserve_dump_area_start = be64_to_cpu(fdm->rgn[0].dest);

/*
* Rarely, but it can so happen that system crashes before all
@@ -155,13 +155,14 @@ static void opal_fadump_get_config(struct fw_dump *fadump_conf,
* Hope the memory that could not be preserved only has pages
* that are usually filtered out while saving the vmcore.
*/
- if (fdm->region_cnt > fdm->registered_regions) {
+ if (be16_to_cpu(fdm->region_cnt) > be16_to_cpu(fdm->registered_regions)) {
pr_warn("Not all memory regions were saved!!!\n");
pr_warn(" Unsaved memory regions:\n");
- i = fdm->registered_regions;
- while (i < fdm->region_cnt) {
+ i = be16_to_cpu(fdm->registered_regions);
+ while (i < be16_to_cpu(fdm->region_cnt)) {
pr_warn("\t[%03d] base: 0x%llx, size: 0x%llx\n",
- i, fdm->rgn[i].src, fdm->rgn[i].size);
+ i, be64_to_cpu(fdm->rgn[i].src),
+ be64_to_cpu(fdm->rgn[i].size));
i++;
}

@@ -170,7 +171,7 @@ static void opal_fadump_get_config(struct fw_dump *fadump_conf,
}

fadump_conf->boot_mem_top = (fadump_conf->boot_memory_size + hole_size);
- fadump_conf->boot_mem_regs_cnt = fdm->region_cnt;
+ fadump_conf->boot_mem_regs_cnt = be16_to_cpu(fdm->region_cnt);
opal_fadump_update_config(fadump_conf, fdm);
}

@@ -178,35 +179,38 @@ static void opal_fadump_get_config(struct fw_dump *fadump_conf,
static void opal_fadump_init_metadata(struct opal_fadump_mem_struct *fdm)
{
fdm->version = OPAL_FADUMP_VERSION;
- fdm->region_cnt = 0;
- fdm->registered_regions = 0;
- fdm->fadumphdr_addr = 0;
+ fdm->region_cnt = cpu_to_be16(0);
+ fdm->registered_regions = cpu_to_be16(0);
+ fdm->fadumphdr_addr = cpu_to_be64(0);
}

static u64 opal_fadump_init_mem_struct(struct fw_dump *fadump_conf)
{
u64 addr = fadump_conf->reserve_dump_area_start;
+ u16 reg_cnt;
int i;

opal_fdm = __va(fadump_conf->kernel_metadata);
opal_fadump_init_metadata(opal_fdm);

/* Boot memory regions */
+ reg_cnt = be16_to_cpu(opal_fdm->region_cnt);
for (i = 0; i < fadump_conf->boot_mem_regs_cnt; i++) {
- opal_fdm->rgn[i].src = fadump_conf->boot_mem_addr[i];
- opal_fdm->rgn[i].dest = addr;
- opal_fdm->rgn[i].size = fadump_conf->boot_mem_sz[i];
+ opal_fdm->rgn[i].src = cpu_to_be64(fadump_conf->boot_mem_addr[i]);
+ opal_fdm->rgn[i].dest = cpu_to_be64(addr);
+ opal_fdm->rgn[i].size = cpu_to_be64(fadump_conf->boot_mem_sz[i]);

- opal_fdm->region_cnt++;
+ reg_cnt++;
addr += fadump_conf->boot_mem_sz[i];
}
+ opal_fdm->region_cnt = cpu_to_be16(reg_cnt);

/*
* Kernel metadata is passed to f/w and retrieved in capture kerenl.
* So, use it to save fadump header address instead of calculating it.
*/
- opal_fdm->fadumphdr_addr = (opal_fdm->rgn[0].dest +
- fadump_conf->boot_memory_size);
+ opal_fdm->fadumphdr_addr = cpu_to_be64(be64_to_cpu(opal_fdm->rgn[0].dest) +
+ fadump_conf->boot_memory_size);

opal_fadump_update_config(fadump_conf, opal_fdm);

@@ -269,18 +273,21 @@ static u64 opal_fadump_get_bootmem_min(void)
static int opal_fadump_register(struct fw_dump *fadump_conf)
{
s64 rc = OPAL_PARAMETER;
+ u16 registered_regs;
int i, err = -EIO;

- for (i = 0; i < opal_fdm->region_cnt; i++) {
+ registered_regs = be16_to_cpu(opal_fdm->registered_regions);
+ for (i = 0; i < be16_to_cpu(opal_fdm->region_cnt); i++) {
rc = opal_mpipl_update(OPAL_MPIPL_ADD_RANGE,
- opal_fdm->rgn[i].src,
- opal_fdm->rgn[i].dest,
- opal_fdm->rgn[i].size);
+ be64_to_cpu(opal_fdm->rgn[i].src),
+ be64_to_cpu(opal_fdm->rgn[i].dest),
+ be64_to_cpu(opal_fdm->rgn[i].size));
if (rc != OPAL_SUCCESS)
break;

- opal_fdm->registered_regions++;
+ registered_regs++;
}
+ opal_fdm->registered_regions = cpu_to_be16(registered_regs);

switch (rc) {
case OPAL_SUCCESS:
@@ -291,7 +298,8 @@ static int opal_fadump_register(struct fw_dump *fadump_conf)
case OPAL_RESOURCE:
/* If MAX regions limit in f/w is hit, warn and proceed. */
pr_warn("%d regions could not be registered for MPIPL as MAX limit is reached!\n",
- (opal_fdm->region_cnt - opal_fdm->registered_regions));
+ (be16_to_cpu(opal_fdm->region_cnt) -
+ be16_to_cpu(opal_fdm->registered_regions)));
fadump_conf->dump_registered = 1;
err = 0;
break;
@@ -312,7 +320,7 @@ static int opal_fadump_register(struct fw_dump *fadump_conf)
* If some regions were registered before OPAL_MPIPL_ADD_RANGE
* OPAL call failed, unregister all regions.
*/
- if ((err < 0) && (opal_fdm->registered_regions > 0))
+ if ((err < 0) && (be16_to_cpu(opal_fdm->registered_regions) > 0))
opal_fadump_unregister(fadump_conf);

return err;
@@ -328,7 +336,7 @@ static int opal_fadump_unregister(struct fw_dump *fadump_conf)
return -EIO;
}

- opal_fdm->registered_regions = 0;
+ opal_fdm->registered_regions = cpu_to_be16(0);
fadump_conf->dump_registered = 0;
return 0;
}
@@ -563,19 +571,20 @@ static void opal_fadump_region_show(struct fw_dump *fadump_conf,
else
fdm_ptr = opal_fdm;

- for (i = 0; i < fdm_ptr->region_cnt; i++) {
+ for (i = 0; i < be16_to_cpu(fdm_ptr->region_cnt); i++) {
/*
* Only regions that are registered for MPIPL
* would have dump data.
*/
if ((fadump_conf->dump_active) &&
- (i < fdm_ptr->registered_regions))
- dumped_bytes = fdm_ptr->rgn[i].size;
+ (i < be16_to_cpu(fdm_ptr->registered_regions)))
+ dumped_bytes = be64_to_cpu(fdm_ptr->rgn[i].size);

seq_printf(m, "DUMP: Src: %#016llx, Dest: %#016llx, ",
- fdm_ptr->rgn[i].src, fdm_ptr->rgn[i].dest);
+ be64_to_cpu(fdm_ptr->rgn[i].src),
+ be64_to_cpu(fdm_ptr->rgn[i].dest));
seq_printf(m, "Size: %#llx, Dumped: %#llx bytes\n",
- fdm_ptr->rgn[i].size, dumped_bytes);
+ be64_to_cpu(fdm_ptr->rgn[i].size), dumped_bytes);
}

/* Dump is active. Show reserved area start address. */
@@ -624,6 +633,7 @@ void __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node)
{
const __be32 *prop;
unsigned long dn;
+ __be64 be_addr;
u64 addr = 0;
int i, len;
s64 ret;
@@ -680,13 +690,13 @@ void __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node)
if (!prop)
return;

- ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_KERNEL, &addr);
- if ((ret != OPAL_SUCCESS) || !addr) {
+ ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_KERNEL, &be_addr);
+ if ((ret != OPAL_SUCCESS) || !be_addr) {
pr_err("Failed to get Kernel metadata (%lld)\n", ret);
return;
}

- addr = be64_to_cpu(addr);
+ addr = be64_to_cpu(be_addr);
pr_debug("Kernel metadata addr: %llx\n", addr);

opal_fdm_active = __va(addr);
@@ -697,14 +707,14 @@ void __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node)
}

/* Kernel regions not registered with f/w for MPIPL */
- if (opal_fdm_active->registered_regions == 0) {
+ if (be16_to_cpu(opal_fdm_active->registered_regions) == 0) {
opal_fdm_active = NULL;
return;
}

- ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_CPU, &addr);
- if (addr) {
- addr = be64_to_cpu(addr);
+ ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_CPU, &be_addr);
+ if (be_addr) {
+ addr = be64_to_cpu(be_addr);
pr_debug("CPU metadata addr: %llx\n", addr);
opal_cpu_metadata = __va(addr);
}
diff --git a/arch/powerpc/platforms/powernv/opal-fadump.h b/arch/powerpc/platforms/powernv/opal-fadump.h
index f1e9ecf548c5..3f715efb0aa6 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.h
+++ b/arch/powerpc/platforms/powernv/opal-fadump.h
@@ -31,14 +31,14 @@
* OPAL FADump kernel metadata
*
* The address of this structure will be registered with f/w for retrieving
- * and processing during crash dump.
+ * in the capture kernel to process the crash dump.
*/
struct opal_fadump_mem_struct {
u8 version;
u8 reserved[3];
- u16 region_cnt; /* number of regions */
- u16 registered_regions; /* Regions registered for MPIPL */
- u64 fadumphdr_addr;
+ __be16 region_cnt; /* number of regions */
+ __be16 registered_regions; /* Regions registered for MPIPL */
+ __be64 fadumphdr_addr;
struct opal_mpipl_region rgn[FADUMP_MAX_MEM_REGS];
} __packed;

@@ -135,7 +135,7 @@ static inline void opal_fadump_read_regs(char *bufp, unsigned int regs_cnt,
for (i = 0; i < regs_cnt; i++, bufp += reg_entry_size) {
reg_entry = (struct hdat_fadump_reg_entry *)bufp;
val = (cpu_endian ? be64_to_cpu(reg_entry->reg_val) :
- reg_entry->reg_val);
+ (u64)(reg_entry->reg_val));
opal_fadump_set_regval_regnum(regs,
be32_to_cpu(reg_entry->reg_type),
be32_to_cpu(reg_entry->reg_num),
--
2.35.1