From: Nathan Chancellor <nathan(a)kernel.org>
commit 3b8b80e993766dc96d1a1c01c62f5d15fafc79b9 upstream.
GCC changed the default C standard dialect from gnu17 to gnu23,
which should not have impacted the kernel because it explicitly requests
the gnu11 standard in the main Makefile. However, there are certain
places in the s390 code that use their own CFLAGS without a '-std='
value, which break with this dialect change because of the kernel's own
definitions of bool, false, and true conflicting with the C23 reserved
keywords.
include/linux/stddef.h:11:9: error: cannot use keyword 'false' as enumeration constant
11 | false = 0,
| ^~~~~
include/linux/stddef.h:11:9: note: 'false' is a keyword with '-std=c23' onwards
include/linux/types.h:35:33: error: 'bool' cannot be defined via 'typedef'
35 | typedef _Bool bool;
| ^~~~
include/linux/types.h:35:33: note: 'bool' is a keyword with '-std=c23' onwards
Add '-std=gnu11' to the decompressor and purgatory CFLAGS to eliminate
these errors and make the C standard version of these areas match the
rest of the kernel.
Cc: stable(a)vger.kernel.org
Signed-off-by: Nathan Chancellor <nathan(a)kernel.org>
Tested-by: Heiko Carstens <hca(a)linux.ibm.com>
Link: https://lore.kernel.org/r/20250122-s390-fix-std-for-gcc-15-v1-1-8b00cadee08…
Signed-off-by: Alexander Gordeev <agordeev(a)linux.ibm.com>
Signed-off-by: Heiko Carstens <hca(a)linux.ibm.com>
---
arch/s390/Makefile | 2 +-
arch/s390/purgatory/Makefile | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 71e3d7c0b870..22dc393b5a83 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -23,7 +23,7 @@ endif
aflags_dwarf := -Wa,-gdwarf-2
KBUILD_AFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -D__ASSEMBLY__
KBUILD_AFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),$(aflags_dwarf))
-KBUILD_CFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -O2
+KBUILD_CFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -O2 -std=gnu11
KBUILD_CFLAGS_DECOMPRESSOR += -DDISABLE_BRANCH_PROFILING -D__NO_FORTIFY
KBUILD_CFLAGS_DECOMPRESSOR += -fno-delete-null-pointer-checks -msoft-float
KBUILD_CFLAGS_DECOMPRESSOR += -fno-asynchronous-unwind-tables
diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile
index 9de56065f28c..2f4d8422bdfb 100644
--- a/arch/s390/purgatory/Makefile
+++ b/arch/s390/purgatory/Makefile
@@ -20,7 +20,7 @@ GCOV_PROFILE := n
UBSAN_SANITIZE := n
KASAN_SANITIZE := n
-KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes
+KBUILD_CFLAGS := -std=gnu11 -fno-strict-aliasing -Wall -Wstrict-prototypes
KBUILD_CFLAGS += -Wno-pointer-sign -Wno-sign-compare
KBUILD_CFLAGS += -fno-zero-initialized-in-bss -fno-builtin -ffreestanding
KBUILD_CFLAGS += -c -MD -Os -m64 -msoft-float -fno-common
--
2.48.1
commit ae952eea6f4a7e2193f8721a5366049946e012e7 upstream.
Note: the GET_LC macro and all the infrastructe that comes with this does
not exist for this kernel release. Therefore the patch is slightly
different to the upstream variant.
In case of stack corruption stack_invalid() is called and the expectation
is that register r10 contains the last breaking event address. This
dependency is quite subtle and broke a couple of years ago without that
anybody noticed.
Fix this by getting rid of the dependency and read the last breaking event
address from lowcore.
Fixes: 56e62a737028 ("s390: convert to generic entry")
Acked-by: Ilya Leoshkevich <iii(a)linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev(a)linux.ibm.com>
Signed-off-by: Heiko Carstens <hca(a)linux.ibm.com>
---
arch/s390/kernel/entry.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index ebad8c8b8c57..0476ce7700df 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -639,7 +639,7 @@ SYM_CODE_START(stack_overflow)
stmg %r0,%r7,__PT_R0(%r11)
stmg %r8,%r9,__PT_PSW(%r11)
mvc __PT_R8(64,%r11),0(%r14)
- stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
+ mvc __PT_ORIG_GPR2(8,%r11),__LC_PGM_LAST_BREAK
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
jg kernel_stack_overflow
--
2.48.1
commit ae952eea6f4a7e2193f8721a5366049946e012e7 upstream.
Note: the GET_LC macro and all the infrastructe that comes with this does
not exist for this kernel release. Therefore the patch is slightly
different to the upstream variant.
In case of stack corruption stack_invalid() is called and the expectation
is that register r10 contains the last breaking event address. This
dependency is quite subtle and broke a couple of years ago without that
anybody noticed.
Fix this by getting rid of the dependency and read the last breaking event
address from lowcore.
Fixes: 56e62a737028 ("s390: convert to generic entry")
Acked-by: Ilya Leoshkevich <iii(a)linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev(a)linux.ibm.com>
Signed-off-by: Heiko Carstens <hca(a)linux.ibm.com>
---
arch/s390/kernel/entry.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 62b80616ca72..576457915625 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -690,7 +690,7 @@ ENTRY(stack_overflow)
stmg %r0,%r7,__PT_R0(%r11)
stmg %r8,%r9,__PT_PSW(%r11)
mvc __PT_R8(64,%r11),0(%r14)
- stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
+ mvc __PT_ORIG_GPR2(8,%r11),__LC_PGM_LAST_BREAK
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
jg kernel_stack_overflow
--
2.48.1
[ Sasha's backport helper bot ]
Hi,
Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it
Found matching upstream commit: 3fea0641b06ff4e53d95d07a96764d8951d4ced6
Note: The patch differs from the upstream commit:
---
1: 3fea0641b06ff ! 1: 14acd457cfe03 f2fs: sysfs: add encoding_flags entry
@@ Commit message
it is a read-only entry to show the value of sb.s_encoding_flags, the
value is hexadecimal.
- ============================ ==========
+ =========================== ==========
Flag_Name Flag_Value
- ============================ ==========
+ =========================== ==========
SB_ENC_STRICT_MODE_FL 0x00000001
SB_ENC_NO_COMPAT_FALLBACK_FL 0x00000002
- ============================ ==========
+ =========================== ==========
case#1
mkfs.f2fs -f -O casefold -C utf8:strict /dev/vda
@@ Commit message
2
Signed-off-by: Chao Yu <chao(a)kernel.org>
- Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org>
## Documentation/ABI/testing/sysfs-fs-f2fs ##
@@ Documentation/ABI/testing/sysfs-fs-f2fs: Description: For several zoned storage devices, vendors will provide extra space
@@ Documentation/ABI/testing/sysfs-fs-f2fs: Description: For several zoned storage
+Description: This is a read-only entry to show the value of sb.s_encoding_flags, the
+ value is hexadecimal.
+
-+ ============================ ==========
++ =========================== ==========
+ Flag_Name Flag_Value
-+ ============================ ==========
++ =========================== ==========
+ SB_ENC_STRICT_MODE_FL 0x00000001
+ SB_ENC_NO_COMPAT_FALLBACK_FL 0x00000002
-+ ============================ ==========
++ =========================== ==========
## fs/f2fs/sysfs.c ##
@@ fs/f2fs/sysfs.c: static ssize_t encoding_show(struct f2fs_attr *a,
---
Results of testing on various branches:
| Branch | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.4.y | Success | Success |
Hello,
Please consider this series for 6.1.y
This patch series backports two patches that implement a test to verify
that a symbol with KSYM_NAME_LEN of 512 can be read.
The first patch implements the test. This commit also includes a fix
for the test x86/insn_decoder_test. In the case a symbol exceeds the
symbol length limit, an error will happen:
arch/x86/tools/insn_decoder_test: error: malformed line 1152000:
tBb_+0xf2>
..which overflowed by 10 characters reading this line:
ffffffff81458193: 74 3d je
ffffffff814581d2
<_RNvXse_NtNtNtCshGpAVYOtgW1_4core4iter8adapters7flattenINtB5_13FlattenCompatINtNtB7_3map3MapNtNtNtBb_3str4iter5CharsNtB1v_17CharEscapeDefaultENtNtBb_4char13EscapeDefaultENtNtBb_3fmt5Debug3fmtBb_+0xf2>
The fix was proposed in [1] and initially mentioned at [2].
The second patch fixes a warning when building with clang because
there was a definition of unlikely from compiler.h in tools/include/linux,
which conflicted with the one in the instruction decoder selftest.
[1] https://lore.kernel.org/lkml/Y9ES4UKl%2F+DtvAVS@gmail.com/
[2] https://lore.kernel.org/lkml/320c4dba-9919-404b-8a26-a8af16be1845@app.fastm…
Signed-off-by: Sergio González Collado <sergio.collado(a)gmail.com>
---
Changes in v2: sign-off patch 2/2
---
Nathan Chancellor (1):
x86/tools: Drop duplicate unlikely() definition in insn_decoder_test.c
Sergio González Collado (1):
Kunit to check the longest symbol length
arch/x86/tools/insn_decoder_test.c | 5 +-
lib/Kconfig.debug | 9 ++++
lib/Makefile | 2 +
lib/longest_symbol_kunit.c | 82 ++++++++++++++++++++++++++++++
4 files changed, 95 insertions(+), 3 deletions(-)
create mode 100644 lib/longest_symbol_kunit.c
base-commit: 58485ff1a74f6c5be9e7c6aafb7293e4337348e7
--
2.39.2
When using Secure TSC, the GUEST_TSC_FREQ MSR reports a frequency based on
the nominal P0 frequency, which deviates slightly (typically ~0.2%) from
the actual mean TSC frequency due to clocking parameters. Over extended VM
uptime, this discrepancy accumulates, causing clock skew between the
hypervisor and SEV-SNP VM, leading to early timer interrupts as perceived
by the guest.
The guest kernel relies on the reported nominal frequency for TSC-based
timekeeping, while the actual frequency set during SNP_LAUNCH_START may
differ. This mismatch results in inaccurate time calculations, causing the
guest to perceive hrtimers as firing earlier than expected.
Utilize the TSC_FACTOR from the SEV firmware's secrets page (see "Secrets
Page Format" in the SNP Firmware ABI Specification) to calculate the mean
TSC frequency, ensuring accurate timekeeping and mitigating clock skew in
SEV-SNP VMs.
Use early_ioremap_encrypted() to map the secrets page as
ioremap_encrypted() uses kmalloc() which is not available during early TSC
initialization and causes a panic.
Fixes: 73bbf3b0fbba ("x86/tsc: Init the TSC for Secure TSC guests")
Reviewed-by: Tom Lendacky <thomas.lendacky(a)amd.com>
Cc: stable(a)vger.kernel.org
Signed-off-by: Nikunj A Dadhania <nikunj(a)amd.com>
---
arch/x86/include/asm/sev.h | 5 ++++-
arch/x86/coco/sev/core.c | 24 ++++++++++++++++++++++++
2 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 58e028d42e41..655d7e37bbcc 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -282,8 +282,11 @@ struct snp_secrets_page {
u8 svsm_guest_vmpl;
u8 rsvd3[3];
+ /* The percentage decrease from nominal to mean TSC frequency. */
+ u32 tsc_factor;
+
/* Remainder of page */
- u8 rsvd4[3744];
+ u8 rsvd4[3740];
} __packed;
struct snp_msg_desc {
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index b6db4e0b936b..ffd44712cec0 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -2167,15 +2167,39 @@ static unsigned long securetsc_get_tsc_khz(void)
void __init snp_secure_tsc_init(void)
{
+ struct snp_secrets_page *secrets;
unsigned long long tsc_freq_mhz;
+ void *mem;
if (!cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
return;
+ mem = early_memremap_encrypted(sev_secrets_pa, PAGE_SIZE);
+ if (!mem) {
+ pr_err("Unable to get TSC_FACTOR: failed to map the SNP secrets page.\n");
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SECURE_TSC);
+ }
+
+ secrets = (__force struct snp_secrets_page *)mem;
+
setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
rdmsrq(MSR_AMD64_GUEST_TSC_FREQ, tsc_freq_mhz);
snp_tsc_freq_khz = (unsigned long)(tsc_freq_mhz * 1000);
+ /*
+ * Obtain the mean TSC frequency by decreasing the nominal TSC frequency with
+ * TSC_FACTOR as documented in the SNP Firmware ABI specification:
+ *
+ * GUEST_TSC_FREQ * (1 - (TSC_FACTOR * 0.00001))
+ *
+ * which is equivalent to:
+ *
+ * GUEST_TSC_FREQ -= (GUEST_TSC_FREQ * TSC_FACTOR) / 100000;
+ */
+ snp_tsc_freq_khz -= (snp_tsc_freq_khz * secrets->tsc_factor) / 100000;
+
x86_platform.calibrate_cpu = securetsc_get_tsc_khz;
x86_platform.calibrate_tsc = securetsc_get_tsc_khz;
+
+ early_memunmap(mem, PAGE_SIZE);
}
base-commit: 337964c8abfbef645cbbe25245e25c11d9d1fc4c
--
2.43.0