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Subject[PATCH v4 27/34] powerpc: Convert to printbuf
Date
This converts from seq_buf to printbuf. We're using printbuf in external
buffer mode, so it's a direct conversion, aside from some trivial
refactoring in cpu_show_meltdown() to make the code more consistent.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
---
arch/powerpc/kernel/process.c | 16 +++--
arch/powerpc/kernel/security.c | 75 ++++++++++-------------
arch/powerpc/platforms/pseries/papr_scm.c | 34 +++++-----
3 files changed, 57 insertions(+), 68 deletions(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 984813a4d5..fb8ba50223 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -39,7 +39,7 @@
#include <linux/uaccess.h>
#include <linux/elf-randomize.h>
#include <linux/pkeys.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>

#include <asm/interrupt.h>
#include <asm/io.h>
@@ -1399,32 +1399,30 @@ void show_user_instructions(struct pt_regs *regs)
{
unsigned long pc;
int n = NR_INSN_TO_PRINT;
- struct seq_buf s;
char buf[96]; /* enough for 8 times 9 + 2 chars */
+ struct printbuf s = PRINTBUF_EXTERN(buf, sizeof(buf));

pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));

- seq_buf_init(&s, buf, sizeof(buf));
-
while (n) {
int i;

- seq_buf_clear(&s);
+ printbuf_reset(&s);

for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
int instr;

if (copy_from_user_nofault(&instr, (void __user *)pc,
sizeof(instr))) {
- seq_buf_printf(&s, "XXXXXXXX ");
+ prt_printf(&s, "XXXXXXXX ");
continue;
}
- seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
+ prt_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
}

- if (!seq_buf_has_overflowed(&s))
+ if (printbuf_remaining(&s))
pr_info("%s[%d]: code: %s\n", current->comm,
- current->pid, s.buffer);
+ current->pid, s.buf);
}
}

diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index d96fd14bd7..b34de62e65 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -10,7 +10,7 @@
#include <linux/memblock.h>
#include <linux/nospec.h>
#include <linux/prctl.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/debugfs.h>

#include <asm/asm-prototypes.h>
@@ -144,31 +144,28 @@ void __init setup_spectre_v2(void)
#ifdef CONFIG_PPC_BOOK3S_64
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
{
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
bool thread_priv;

thread_priv = security_ftr_enabled(SEC_FTR_L1D_THREAD_PRIV);

if (rfi_flush) {
- struct seq_buf s;
- seq_buf_init(&s, buf, PAGE_SIZE - 1);

- seq_buf_printf(&s, "Mitigation: RFI Flush");
+ prt_printf(&s, "Mitigation: RFI Flush");
if (thread_priv)
- seq_buf_printf(&s, ", L1D private per thread");
-
- seq_buf_printf(&s, "\n");
-
- return s.len;
+ prt_printf(&s, ", L1D private per thread");
+
+ prt_printf(&s, "\n");
+ } else if (thread_priv) {
+ prt_printf(&s, "Vulnerable: L1D private per thread\n");
+ } else if (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) &&
+ !security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)) {
+ prt_printf(&s, "Not affected\n");
+ } else {
+ prt_printf(&s, "Vulnerable\n");
}

- if (thread_priv)
- return sprintf(buf, "Vulnerable: L1D private per thread\n");
-
- if (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) &&
- !security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR))
- return sprintf(buf, "Not affected\n");
-
- return sprintf(buf, "Vulnerable\n");
+ return printbuf_written(&s);
}

ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf)
@@ -179,70 +176,66 @@ ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *b

ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct seq_buf s;
-
- seq_buf_init(&s, buf, PAGE_SIZE - 1);
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);

if (security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)) {
if (barrier_nospec_enabled)
- seq_buf_printf(&s, "Mitigation: __user pointer sanitization");
+ prt_printf(&s, "Mitigation: __user pointer sanitization");
else
- seq_buf_printf(&s, "Vulnerable");
+ prt_printf(&s, "Vulnerable");

if (security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31))
- seq_buf_printf(&s, ", ori31 speculation barrier enabled");
+ prt_printf(&s, ", ori31 speculation barrier enabled");

- seq_buf_printf(&s, "\n");
+ prt_printf(&s, "\n");
} else
- seq_buf_printf(&s, "Not affected\n");
+ prt_printf(&s, "Not affected\n");

- return s.len;
+ return printbuf_written(&s);
}

ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct seq_buf s;
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
bool bcs, ccd;

- seq_buf_init(&s, buf, PAGE_SIZE - 1);
-
bcs = security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED);
ccd = security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED);

if (bcs || ccd) {
- seq_buf_printf(&s, "Mitigation: ");
+ prt_printf(&s, "Mitigation: ");

if (bcs)
- seq_buf_printf(&s, "Indirect branch serialisation (kernel only)");
+ prt_printf(&s, "Indirect branch serialisation (kernel only)");

if (bcs && ccd)
- seq_buf_printf(&s, ", ");
+ prt_printf(&s, ", ");

if (ccd)
- seq_buf_printf(&s, "Indirect branch cache disabled");
+ prt_printf(&s, "Indirect branch cache disabled");

} else if (count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE) {
- seq_buf_printf(&s, "Mitigation: Software count cache flush");
+ prt_printf(&s, "Mitigation: Software count cache flush");

if (count_cache_flush_type == BRANCH_CACHE_FLUSH_HW)
- seq_buf_printf(&s, " (hardware accelerated)");
+ prt_printf(&s, " (hardware accelerated)");

} else if (btb_flush_enabled) {
- seq_buf_printf(&s, "Mitigation: Branch predictor state flush");
+ prt_printf(&s, "Mitigation: Branch predictor state flush");
} else {
- seq_buf_printf(&s, "Vulnerable");
+ prt_printf(&s, "Vulnerable");
}

if (bcs || ccd || count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE) {
if (link_stack_flush_type != BRANCH_CACHE_FLUSH_NONE)
- seq_buf_printf(&s, ", Software link stack flush");
+ prt_printf(&s, ", Software link stack flush");
if (link_stack_flush_type == BRANCH_CACHE_FLUSH_HW)
- seq_buf_printf(&s, " (hardware accelerated)");
+ prt_printf(&s, " (hardware accelerated)");
}

- seq_buf_printf(&s, "\n");
+ prt_printf(&s, "\n");

- return s.len;
+ return printbuf_written(&s);
}

#ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index 39962c9055..317d4513db 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -12,7 +12,7 @@
#include <linux/libnvdimm.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/nd.h>

#include <asm/plpar_wrappers.h>
@@ -1145,7 +1145,7 @@ static ssize_t perf_stats_show(struct device *dev,
{
int index;
ssize_t rc;
- struct seq_buf s;
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
struct papr_scm_perf_stat *stat;
struct papr_scm_perf_stats *stats;
struct nvdimm *dimm = to_nvdimm(dev);
@@ -1168,18 +1168,17 @@ static ssize_t perf_stats_show(struct device *dev,
* values. Since stat_id is essentially a char string of
* 8 bytes, simply use the string format specifier to print it.
*/
- seq_buf_init(&s, buf, PAGE_SIZE);
for (index = 0, stat = stats->scm_statistic;
index < be32_to_cpu(stats->num_statistics);
++index, ++stat) {
- seq_buf_printf(&s, "%.8s = 0x%016llX\n",
- stat->stat_id,
- be64_to_cpu(stat->stat_val));
+ prt_printf(&s, "%.8s = 0x%016llX\n",
+ stat->stat_id,
+ be64_to_cpu(stat->stat_val));
}

free_stats:
kfree(stats);
- return rc ? rc : (ssize_t)seq_buf_used(&s);
+ return rc ?: printbuf_written(&s);
}
static DEVICE_ATTR_ADMIN_RO(perf_stats);

@@ -1188,7 +1187,7 @@ static ssize_t flags_show(struct device *dev,
{
struct nvdimm *dimm = to_nvdimm(dev);
struct papr_scm_priv *p = nvdimm_provider_data(dimm);
- struct seq_buf s;
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
u64 health;
int rc;

@@ -1199,29 +1198,28 @@ static ssize_t flags_show(struct device *dev,
/* Copy health_bitmap locally, check masks & update out buffer */
health = READ_ONCE(p->health_bitmap);

- seq_buf_init(&s, buf, PAGE_SIZE);
if (health & PAPR_PMEM_UNARMED_MASK)
- seq_buf_printf(&s, "not_armed ");
+ prt_printf(&s, "not_armed ");

if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
- seq_buf_printf(&s, "flush_fail ");
+ prt_printf(&s, "flush_fail ");

if (health & PAPR_PMEM_BAD_RESTORE_MASK)
- seq_buf_printf(&s, "restore_fail ");
+ prt_printf(&s, "restore_fail ");

if (health & PAPR_PMEM_ENCRYPTED)
- seq_buf_printf(&s, "encrypted ");
+ prt_printf(&s, "encrypted ");

if (health & PAPR_PMEM_SMART_EVENT_MASK)
- seq_buf_printf(&s, "smart_notify ");
+ prt_printf(&s, "smart_notify ");

if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
- seq_buf_printf(&s, "scrubbed locked ");
+ prt_printf(&s, "scrubbed locked ");

- if (seq_buf_used(&s))
- seq_buf_printf(&s, "\n");
+ if (printbuf_written(&s))
+ prt_printf(&s, "\n");

- return seq_buf_used(&s);
+ return printbuf_written(&s);
}
DEVICE_ATTR_RO(flags);

--
2.36.1
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