5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Douglas Anderson <dianders@xxxxxxxxxxxx>
[ Upstream commit 293f53263266bc4340d777268ab4328a97f041fa ]
If the allocation in msm_disp_state_dump_regs() failed then
`block->state` can be NULL. The msm_disp_state_print_regs() function
_does_ have code to try to handle it with:
if (*reg)
dump_addr = *reg;
...but since "dump_addr" is initialized to NULL the above is actually
a noop. The code then goes on to dereference `dump_addr`.
Make the function print "Registers not stored" when it sees a NULL to
solve this. Since we're touching the code, fix
msm_disp_state_print_regs() not to pointlessly take a double-pointer
and properly mark the pointer as `const`.
Fixes: 98659487b845 ("drm/msm: add support to take dpu snapshot")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Patchwork: https://patchwork.freedesktop.org/patch/619657/
Link: https://lore.kernel.org/r/20241014093605.1.Ia1217cecec9ef09eb3c6d125360cc6c8574b0e73@changeid
Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
index 8746ceae8fca9..06f2f5a5e267e 100644
--- a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
+++ b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
@@ -46,20 +46,21 @@ static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *b
}
}
-static void msm_disp_state_print_regs(u32 **reg, u32 len, void __iomem *base_addr,
- struct drm_printer *p)
+static void msm_disp_state_print_regs(const u32 *dump_addr, u32 len,
+ void __iomem *base_addr, struct drm_printer *p)
{
int i;
- u32 *dump_addr = NULL;
void __iomem *addr;
u32 num_rows;
+ if (!dump_addr) {
+ drm_printf(p, "Registers not stored\n");
+ return;
+ }
+
addr = base_addr;
num_rows = len / REG_DUMP_ALIGN;
- if (*reg)
- dump_addr = *reg;
-
for (i = 0; i < num_rows; i++) {
drm_printf(p, "0x%lx : %08x %08x %08x %08x\n",
(unsigned long)(addr - base_addr),
@@ -86,7 +87,7 @@ void msm_disp_state_print(struct msm_disp_state *state, struct drm_printer *p)
list_for_each_entry_safe(block, tmp, &state->blocks, node) {
drm_printf(p, "====================%s================\n", block->name);
- msm_disp_state_print_regs(&block->state, block->size, block->base_addr, p);
+ msm_disp_state_print_regs(block->state, block->size, block->base_addr, p);
}
drm_printf(p, "===================dpu drm state================\n");
--
2.43.0
