From 9baff597ce021f7691187b0d1d1bbc16d07b13e1 Mon Sep 17 00:00:00 2001 From: Ray Strode Date: Thu, 16 Aug 2018 16:37:25 -0400 Subject: [PATCH] gallium/winsys/kms: don't unmap what wasn't mapped At the moment, depending on pipe transfer flags, the dumb buffer map address can end up at either kms_sw_dt->ro_mapped or kms_sw_dt->mapped. When it's time to unmap the dumb buffer, both locations get unmapped, even though one is probably initialized to 0. That leads to the code segment getting unmapped at runtime and crashes when trying to call into unrelated code. This commit addresses the problem by using MAP_FAILED instead of NULL for ro_mapped and mapped when the dumb buffer is unmapped, and only unmapping mapped addresses at unmap time. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107098 Signed-off-by: Ray Strode Fixes: d891f28df9a ("gallium/winsys/kms: Fix possible leak in map/unmap.") Cc: Lepton Wu Reviewed-by: Emil Velikov --- src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c b/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c index 3fe1b1a7313..9564d9424b1 100644 --- a/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c +++ b/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c @@ -176,6 +176,8 @@ kms_sw_displaytarget_create(struct sw_winsys *ws, list_inithead(&kms_sw_dt->planes); kms_sw_dt->ref_count = 1; + kms_sw_dt->mapped = MAP_FAILED; + kms_sw_dt->ro_mapped = MAP_FAILED; kms_sw_dt->format = format; @@ -262,7 +264,7 @@ kms_sw_displaytarget_map(struct sw_winsys *ws, prot = (flags == PIPE_TRANSFER_READ) ? PROT_READ : (PROT_READ | PROT_WRITE); void **ptr = (flags == PIPE_TRANSFER_READ) ? &kms_sw_dt->ro_mapped : &kms_sw_dt->mapped; - if (!*ptr) { + if (*ptr == MAP_FAILED) { void *tmp = mmap(0, kms_sw_dt->size, prot, MAP_SHARED, kms_sw->fd, map_req.offset); if (tmp == MAP_FAILED) @@ -332,6 +334,8 @@ kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys *kms_sw, int fd, FREE(kms_sw_dt); return NULL; } + kms_sw_dt->mapped = MAP_FAILED; + kms_sw_dt->ro_mapped = MAP_FAILED; kms_sw_dt->size = lseek_ret; kms_sw_dt->ref_count = 1; kms_sw_dt->handle = handle; @@ -368,10 +372,14 @@ kms_sw_displaytarget_unmap(struct sw_winsys *ws, DEBUG_PRINT("KMS-DEBUG: unmapped buffer %u (was %p)\n", kms_sw_dt->handle, kms_sw_dt->mapped); DEBUG_PRINT("KMS-DEBUG: unmapped buffer %u (was %p)\n", kms_sw_dt->handle, kms_sw_dt->ro_mapped); - munmap(kms_sw_dt->mapped, kms_sw_dt->size); - kms_sw_dt->mapped = NULL; - munmap(kms_sw_dt->ro_mapped, kms_sw_dt->size); - kms_sw_dt->ro_mapped = NULL; + if (kms_sw_dt->mapped != MAP_FAILED) { + munmap(kms_sw_dt->mapped, kms_sw_dt->size); + kms_sw_dt->mapped = MAP_FAILED; + } + if (kms_sw_dt->ro_mapped != MAP_FAILED) { + munmap(kms_sw_dt->ro_mapped, kms_sw_dt->size); + kms_sw_dt->ro_mapped = MAP_FAILED; + } } static struct sw_displaytarget * -- 2.11.0