[PATCH AUTOSEL 5.18 41/93] amdgpu/pm: Fix possible array out-of-bounds if SCLK levels != 2

Sasha Levin
2022-08-11T15:57:27Z

From: Darren Powell <darren.powell@amd.com>

[ Upstream commit ceb180361e3851007547c55035cd1de03f108f75 ]

[v2]
simplified fix after Lijo's feedback
removed clocks.num_levels from calculation of loop count
removed unsafe accesses to shim table freq_values
retained corner case output only min,now if
clocks.num_levels == 1 && now > min

[v1]
added a check to populate and use SCLK shim table freq_values only
if using dpm_level == AMD_DPM_FORCED_LEVEL_MANUAL or
AMD_DPM_FORCED_LEVEL_PERF_DETERMINISM
removed clocks.num_levels from calculation of shim table size
removed unsafe accesses to shim table freq_values
output gfx_table values if using other dpm levels
added check for freq_match when using freq_values for when now == min_clk

== Test ==
LOGFILE=aldebaran-sclk.test.log
AMDGPU_PCI_ADDR=`lspci -nn | grep "VGA\|Display" | cut -d " " -f 1`
AMDGPU_HWMON=`ls -la /sys/class/hwmon | grep $AMDGPU_PCI_ADDR | awk '{print $9}'`
HWMON_DIR=/sys/class/hwmon/${AMDGPU_HWMON}

lspci -nn | grep "VGA\|Display" > $LOGFILE
FILES="pp_od_clk_voltage
pp_dpm_sclk"

for f in $FILES
do
echo === $f === >> $LOGFILE
cat $HWMON_DIR/device/$f >> $LOGFILE
done
cat $LOGFILE

Signed-off-by: Darren Powell <darren.powell@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../drm/amd/pm/swsmu/smu13/aldebaran_ppt.c | 34 +++++++------------
1 file changed, 12 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
index 7f998f24af81..b57750cb27c4 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
@@ -733,7 +733,7 @@ static int aldebaran_print_clk_levels(struct smu_context *smu,
struct smu_13_0_dpm_table *single_dpm_table;
struct smu_dpm_context *smu_dpm = &smu->smu_dpm;
struct smu_13_0_dpm_context *dpm_context = NULL;
- uint32_t display_levels;
+ int display_levels;
uint32_t freq_values[3] = {0};
uint32_t min_clk, max_clk;

@@ -765,7 +765,7 @@ static int aldebaran_print_clk_levels(struct smu_context *smu,
return ret;
}

- display_levels = clocks.num_levels;
+ display_levels = (clocks.num_levels == 1) ? 1 : 2;

min_clk = pstate_table->gfxclk_pstate.curr.min;
max_clk = pstate_table->gfxclk_pstate.curr.max;
@@ -775,30 +775,20 @@ static int aldebaran_print_clk_levels(struct smu_context *smu,

/* fine-grained dpm has only 2 levels */
if (now > min_clk && now < max_clk) {
- display_levels = clocks.num_levels + 1;
+ display_levels++;
freq_values[2] = max_clk;
freq_values[1] = now;
}

- /*
- * For DPM disabled case, there will be only one clock level.
- * And it's safe to assume that is always the current clock.
- */
- if (display_levels == clocks.num_levels) {
- for (i = 0; i < clocks.num_levels; i++)
- size += sysfs_emit_at(buf, size, "%d: %uMhz %s\n", i,
- freq_values[i],
- (clocks.num_levels == 1) ?
- "*" :
- (aldebaran_freqs_in_same_level(
- freq_values[i], now) ?
- "*" :
- ""));
- } else {
- for (i = 0; i < display_levels; i++)
- size += sysfs_emit_at(buf, size, "%d: %uMhz %s\n", i,
- freq_values[i], i == 1 ? "*" : "");
- }
+ for (i = 0; i < display_levels; i++)
+ size += sysfs_emit_at(buf, size, "%d: %uMhz %s\n", i,
+ freq_values[i],
+ (display_levels == 1) ?
+ "*" :
+ (aldebaran_freqs_in_same_level(
+ freq_values[i], now) ?
+ "*" :
+ ""));

break;

--
2.35.1