com32: replace hard-coded bounce buffer use in com32/libsyslinux-4.00-pre25

Replace hard-coded bounce buffer uses in com32/lib with lmalloc/lfree.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

3 files changed, 59 insertions, 29 deletions

diff --git a/com32/lib/sys/gpxe.c b/com32/lib/sys/gpxe.c
index fae03f8f..d86da42a 100644
--- a/com32/lib/sys/gpxe.c
+++ b/com32/lib/sys/gpxe.c
@@ -7,39 +7,44 @@ bool is_gpxe(void)
     const struct syslinux_version *sv;
     com32sys_t reg;
     struct s_PXENV_FILE_CHECK_API *fca;
+    bool gpxe;
 
     sv = syslinux_version();
     if (sv->filesystem != SYSLINUX_FS_PXELINUX)
         return false;           /* Not PXELINUX */
 
-    fca = __com32.cs_bounce;
-    memset(fca, 0, sizeof *fca);
+    fca = lzalloc(sizeof *fca);
+    if (!fca)
+	return false;
     fca->Size = sizeof *fca;
     fca->Magic = 0x91d447b2;
 
     memset(&reg, 0, sizeof reg);
     reg.eax.w[0] = 0x0009;
     reg.ebx.w[0] = 0x00e6;      /* PXENV_FILE_API_CHECK */
-    reg.edi.w[0] = OFFS(fca);
+    /* reg.edi.w[0] = OFFS(fca); */
     reg.es = SEG(fca);
 
     __intcall(0x22, &reg, &reg);
 
+    gpxe = true;
+
     if (reg.eflags.l & EFLAGS_CF)
-        return false;           /* Cannot invoke PXE stack */
+	gpxe = false;           /* Cannot invoke PXE stack */
 
     if (reg.eax.w[0] || fca->Status)
-        return false;           /* PXE failure */
+        gpxe = false;           /* PXE failure */
 
     if (fca->Magic != 0xe9c17b20)
-        return false;           /* Incorrect magic */
+        gpxe = false;           /* Incorrect magic */
 
     if (fca->Size < sizeof *fca)
-        return false;           /* Short return */
+        gpxe = false;           /* Short return */
 
+    /* XXX: The APIs to test for should be a passed-in option */
     if (!(fca->APIMask & (1 << 5)))
-        return false;           /* No FILE EXEC */
+	gpxe = false;           /* No FILE EXEC */
 
-    return true;
+    lfree(fca);
+    return gpxe;
 }
-
diff --git a/com32/lib/sys/open.c b/com32/lib/sys/open.c
index 0bd490c7..94465925 100644
--- a/com32/lib/sys/open.c
+++ b/com32/lib/sys/open.c
@@ -55,6 +55,7 @@ int open(const char *pathname, int flags, ...)
     com32sys_t regs;
     int fd;
     struct file_info *fp;
+    char *lm_pathname;
 
     fd = opendev(&__file_dev, NULL, flags);
 
@@ -63,14 +64,18 @@ int open(const char *pathname, int flags, ...)
 
     fp = &__file_info[fd];
 
-    strlcpy(__com32.cs_bounce, pathname, __com32.cs_bounce_size);
+    lm_pathname = lstrdup(pathname);
+    if (!lm_pathname)
+	return -1;
 
     regs.eax.w[0] = 0x0006;
-    regs.esi.w[0] = OFFS(__com32.cs_bounce);
-    regs.es = SEG(__com32.cs_bounce);
+    regs.esi.w[0] = OFFS(lm_pathname);
+    regs.es = SEG(lm_pathname);
 
     __com32.cs_intcall(0x22, &regs, &regs);
 
+    lfree(lm_pathname);
+
     if ((regs.eflags.l & EFLAGS_CF) || regs.esi.w[0] == 0) {
 	close(fd);
 	errno = ENOENT;
diff --git a/com32/lib/sys/vesa/initvesa.c b/com32/lib/sys/vesa/initvesa.c
index 0a436f4c..9a1ae384 100644
--- a/com32/lib/sys/vesa/initvesa.c
+++ b/com32/lib/sys/vesa/initvesa.c
@@ -95,9 +95,13 @@ static int vesacon_set_mode(int x, int y)
     com32sys_t rm;
     uint8_t *rom_font;
     uint16_t mode, bestmode, *mode_ptr;
+    struct vesa_info *vi;
     struct vesa_general_info *gi;
     struct vesa_mode_info *mi;
     enum vesa_pixel_format pxf, bestpxf;
+    int err = 0;
+
+    debug("Hello, World!\r\n");
 
     /* Free any existing data structures */
     if (__vesacon_background) {
@@ -110,13 +114,15 @@ static int vesacon_set_mode(int x, int y)
     }
 
     /* Allocate space in the bounce buffer for these structures */
-    gi = &((struct vesa_info *)__com32.cs_bounce)->gi;
-    mi = &((struct vesa_info *)__com32.cs_bounce)->mi;
-
-    debug("Hello, World!\r\n");
+    vi = lzalloc(sizeof *vi);
+    if (!vi) {
+	err = 10;		/* Out of memory */
+	goto exit;
+    }
+    gi = &vi->gi;
+    mi = &vi->mi;
 
     memset(&rm, 0, sizeof rm);
-    memset(gi, 0, sizeof *gi);
 
     gi->signature = VBE2_MAGIC;	/* Get VBE2 extended data */
     rm.eax.w[0] = 0x4F00;	/* Get SVGA general information */
@@ -124,12 +130,18 @@ static int vesacon_set_mode(int x, int y)
     rm.es = SEG(gi);
     __intcall(0x10, &rm, &rm);
 
-    if (rm.eax.w[0] != 0x004F)
-	return 1;		/* Function call failed */
-    if (gi->signature != VESA_MAGIC)
-	return 2;		/* No magic */
-    if (gi->version < 0x0102)
-	return 3;		/* VESA 1.2+ required */
+    if (rm.eax.w[0] != 0x004F) {
+	err = 1;		/* Function call failed */
+	goto exit;
+    }
+    if (gi->signature != VESA_MAGIC) {
+	err = 2;		/* No magic */
+	goto exit;
+    }
+    if (gi->version < 0x0102) {
+	err = 3;		/* VESA 1.2+ required */
+	goto exit;
+    }
 
     /* Copy general info */
     memcpy(&__vesa_info.gi, gi, sizeof *gi);
@@ -232,8 +244,10 @@ static int vesacon_set_mode(int x, int y)
 	}
     }
 
-    if (bestpxf == PXF_NONE)
-	return 4;		/* No mode found */
+    if (bestpxf == PXF_NONE) {
+	err = 4;		/* No mode found */
+	goto exit;
+    }
 
     mi = &__vesa_info.mi;
     mode = bestmode;
@@ -260,8 +274,10 @@ static int vesacon_set_mode(int x, int y)
 	mode |= 0x4000;		/* Request linear framebuffer if supported */
     rm.ebx.w[0] = mode;
     __intcall(0x10, &rm, &rm);
-    if (rm.eax.w[0] != 0x004F)
-	return 9;		/* Failed to set mode */
+    if (rm.eax.w[0] != 0x004F) {
+	err = 9;		/* Failed to set mode */
+	goto exit;
+    }
 
     __vesacon_background = calloc(mi->h_res*mi->v_res, 4);
     __vesacon_shadowfb = calloc(mi->h_res*mi->v_res, 4);
@@ -279,7 +295,11 @@ static int vesacon_set_mode(int x, int y)
 
     __vesacon_pixel_format = bestpxf;
 
-    return 0;
+exit:
+    if (vi)
+	lfree(vi);
+
+    return err;
 }
 
 static int init_text_display(void)