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R_GenerateBlendTables: allocate copy of palette for use in thread

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The palette can be freed while this thread is still
running, which means the thread would end up reading from
freed memory.
This commit is contained in:
James R 2023-08-28 01:55:34 -07:00
parent fd346db927
commit b1782793b5
2 changed files with 38 additions and 13 deletions
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50
src/r_draw.c
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@ -200,7 +200,13 @@ CV_PossibleValue_t Color_cons_t[MAXSKINCOLORS+1];
#define TRANSTAB_AMTMUL10 (255.0f / 10.0f)
static void R_GenerateBlendTables(void);
struct GenerateBlendTables_State
{
RGBA_t *masterPalette;
RGBA_t *gammaCorrectedPalette;
};
static void R_GenerateBlendTables_Core(struct GenerateBlendTables_State *state);
static void R_GenerateTranslucencyTable(UINT8 *table, RGBA_t* sourcepal, int style, UINT8 blendamt);
static void R_AllocateBlendTables(void)
@ -221,8 +227,13 @@ static void R_AllocateBlendTables(void)
#ifdef HAVE_THREADS
static void R_GenerateBlendTables_Thread(void *userdata)
{
(void)userdata;
R_GenerateBlendTables();
struct GenerateBlendTables_State *state = userdata;
R_GenerateBlendTables_Core(state);
free(state->masterPalette);
free(state->gammaCorrectedPalette);
free(state);
}
#endif
@ -247,16 +258,29 @@ void R_InitTranslucencyTables(void)
W_ReadLump(W_GetNumForName("TRANS90"), transtables+0x80000);
R_AllocateBlendTables();
#ifdef HAVE_THREADS
I_spawn_thread("blend-tables",
R_GenerateBlendTables_Thread, NULL);
#else
R_GenerateBlendTables();
#endif
}
void R_GenerateBlendTables(void)
{
#ifdef HAVE_THREADS
// Allocate copies for the worker thread since the originals can be freed in the main thread.
struct GenerateBlendTables_State *state = malloc(sizeof *state);
size_t palsize = 256 * sizeof(RGBA_t);
state->masterPalette = memcpy(malloc(palsize), pMasterPalette, palsize);
state->gammaCorrectedPalette = memcpy(malloc(palsize), pGammaCorrectedPalette, palsize);
I_spawn_thread("blend-tables",
R_GenerateBlendTables_Thread, state);
#else
struct GenerateBlendTables_State state = {pMasterPalette, pGammaCorrectedPalette};
R_GenerateBlendTables_Core(&state);
#endif
}
static void R_GenerateBlendTables_Core(struct GenerateBlendTables_State *state)
{
INT32 i;
@ -265,12 +289,12 @@ void R_GenerateBlendTables(void)
const size_t offs = (0x10000 * i);
const UINT8 alpha = (TRANSTAB_AMTMUL10 * ((float)(10-i)));
R_GenerateTranslucencyTable(blendtables[blendtab_add] + offs, pGammaCorrectedPalette, AST_ADD, alpha);
R_GenerateTranslucencyTable(blendtables[blendtab_subtract] + offs, pMasterPalette, AST_SUBTRACT, alpha); // intentionally uses pMasterPalette
R_GenerateTranslucencyTable(blendtables[blendtab_reversesubtract] + offs, pGammaCorrectedPalette, AST_REVERSESUBTRACT, alpha);
R_GenerateTranslucencyTable(blendtables[blendtab_add] + offs, state->gammaCorrectedPalette, AST_ADD, alpha);
R_GenerateTranslucencyTable(blendtables[blendtab_subtract] + offs, state->masterPalette, AST_SUBTRACT, alpha); // intentionally uses pMasterPalette
R_GenerateTranslucencyTable(blendtables[blendtab_reversesubtract] + offs, state->gammaCorrectedPalette, AST_REVERSESUBTRACT, alpha);
}
R_GenerateTranslucencyTable(blendtables[blendtab_modulate], pGammaCorrectedPalette, AST_MODULATE, 0);
R_GenerateTranslucencyTable(blendtables[blendtab_modulate], state->gammaCorrectedPalette, AST_MODULATE, 0);
}
void R_GenerateTranslucencyTable(UINT8 *table, RGBA_t* sourcepal, int style, UINT8 blendamt)

1
src/r_draw.h
View file

@ -157,6 +157,7 @@ enum
extern UINT8 *blendtables[NUMBLENDMAPS];
void R_InitTranslucencyTables(void);
void R_GenerateBlendTables(void);
UINT8 *R_GetTranslucencyTable(INT32 alphalevel);
UINT8 *R_GetBlendTable(int style, INT32 alphalevel);