6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nathan Lynch <nathanl@xxxxxxxxxxxxx>
[ Upstream commit 7bdd1c6c87de758750d419eedab7285b95b66417 ]
cur_cpu_spec->cpu_name is appended to ppc_hw_desc before cur_cpu_spec
has taken on its final value. This is illustrated on pseries by
comparing the CPU name as reported at boot ("POWER8E (raw)") to the
contents of /proc/cpuinfo ("POWER8 (architected)"):
$ dmesg | grep Hardware
Hardware name: IBM,8408-E8E POWER8E (raw) 0x4b0201 0xf000004 \
of:IBM,FW860.50 (SV860_146) hv:phyp pSeries
$ grep -m 1 ^cpu /proc/cpuinfo
cpu : POWER8 (architected), altivec supported
Some 44x models would appear to be affected as well; see
identical_pvr_fixup().
This results in incorrect CPU information in stack dumps --
ppc_hw_desc is an input to dump_stack_set_arch_desc().
Delay gathering the CPU name until after all potential calls to
identify_cpu().
Signed-off-by: Nathan Lynch <nathanl@xxxxxxxxxxxxx>
Fixes: bd649d40e0f2 ("powerpc: Add PVR & CPU name to hardware description")
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://msgid.link/20240603-fix-cpu-hwdesc-v1-1-945f2850fcaa@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/powerpc/kernel/prom.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 77364729a1b61..bf6d8ad3819e9 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -327,6 +327,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
void *data)
{
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+ const __be32 *cpu_version = NULL;
const __be32 *prop;
const __be32 *intserv;
int i, nthreads;
@@ -410,7 +411,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000) {
identify_cpu(0, be32_to_cpup(prop));
- seq_buf_printf(&ppc_hw_desc, "0x%04x ", be32_to_cpup(prop));
+ cpu_version = prop;
}
check_cpu_feature_properties(node);
@@ -421,6 +422,12 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
}
identical_pvr_fixup(node);
+
+ // We can now add the CPU name & PVR to the hardware description
+ seq_buf_printf(&ppc_hw_desc, "%s 0x%04lx ", cur_cpu_spec->cpu_name, mfspr(SPRN_PVR));
+ if (cpu_version)
+ seq_buf_printf(&ppc_hw_desc, "0x%04x ", be32_to_cpup(cpu_version));
+
init_mmu_slb_size(node);
#ifdef CONFIG_PPC64
@@ -858,9 +865,6 @@ void __init early_init_devtree(void *params)
dt_cpu_ftrs_scan();
- // We can now add the CPU name & PVR to the hardware description
- seq_buf_printf(&ppc_hw_desc, "%s 0x%04lx ", cur_cpu_spec->cpu_name, mfspr(SPRN_PVR));
-
/* Retrieve CPU related informations from the flat tree
* (altivec support, boot CPU ID, ...)
*/
--
2.43.0
