From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/video/fbdev/sunxvr1000.c | 197 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 197 insertions(+) create mode 100644 drivers/video/fbdev/sunxvr1000.c (limited to 'drivers/video/fbdev/sunxvr1000.c') diff --git a/drivers/video/fbdev/sunxvr1000.c b/drivers/video/fbdev/sunxvr1000.c new file mode 100644 index 000000000..a93b06614 --- /dev/null +++ b/drivers/video/fbdev/sunxvr1000.c @@ -0,0 +1,197 @@ +/* sunxvr1000.c: Sun XVR-1000 fb driver for sparc64 systems + * + * License: GPL + * + * Copyright (C) 2010 David S. Miller (davem@davemloft.net) + */ + +#include +#include +#include +#include +#include + +struct gfb_info { + struct fb_info *info; + + char __iomem *fb_base; + unsigned long fb_base_phys; + + struct device_node *of_node; + + unsigned int width; + unsigned int height; + unsigned int depth; + unsigned int fb_size; + + u32 pseudo_palette[16]; +}; + +static int gfb_get_props(struct gfb_info *gp) +{ + gp->width = of_getintprop_default(gp->of_node, "width", 0); + gp->height = of_getintprop_default(gp->of_node, "height", 0); + gp->depth = of_getintprop_default(gp->of_node, "depth", 32); + + if (!gp->width || !gp->height) { + printk(KERN_ERR "gfb: Critical properties missing for %pOF\n", + gp->of_node); + return -EINVAL; + } + + return 0; +} + +static int gfb_setcolreg(unsigned regno, + unsigned red, unsigned green, unsigned blue, + unsigned transp, struct fb_info *info) +{ + u32 value; + + if (regno < 16) { + red >>= 8; + green >>= 8; + blue >>= 8; + + value = (blue << 16) | (green << 8) | red; + ((u32 *)info->pseudo_palette)[regno] = value; + } + + return 0; +} + +static const struct fb_ops gfb_ops = { + .owner = THIS_MODULE, + FB_DEFAULT_IOMEM_OPS, + .fb_setcolreg = gfb_setcolreg, +}; + +static int gfb_set_fbinfo(struct gfb_info *gp) +{ + struct fb_info *info = gp->info; + struct fb_var_screeninfo *var = &info->var; + + info->fbops = &gfb_ops; + info->screen_base = gp->fb_base; + info->screen_size = gp->fb_size; + + info->pseudo_palette = gp->pseudo_palette; + + /* Fill fix common fields */ + strscpy(info->fix.id, "gfb", sizeof(info->fix.id)); + info->fix.smem_start = gp->fb_base_phys; + info->fix.smem_len = gp->fb_size; + info->fix.type = FB_TYPE_PACKED_PIXELS; + if (gp->depth == 32 || gp->depth == 24) + info->fix.visual = FB_VISUAL_TRUECOLOR; + else + info->fix.visual = FB_VISUAL_PSEUDOCOLOR; + + var->xres = gp->width; + var->yres = gp->height; + var->xres_virtual = var->xres; + var->yres_virtual = var->yres; + var->bits_per_pixel = gp->depth; + + var->red.offset = 0; + var->red.length = 8; + var->green.offset = 8; + var->green.length = 8; + var->blue.offset = 16; + var->blue.length = 8; + var->transp.offset = 0; + var->transp.length = 0; + + if (fb_alloc_cmap(&info->cmap, 256, 0)) { + printk(KERN_ERR "gfb: Cannot allocate color map.\n"); + return -ENOMEM; + } + + return 0; +} + +static int gfb_probe(struct platform_device *op) +{ + struct device_node *dp = op->dev.of_node; + struct fb_info *info; + struct gfb_info *gp; + int err; + + info = framebuffer_alloc(sizeof(struct gfb_info), &op->dev); + if (!info) { + err = -ENOMEM; + goto err_out; + } + + gp = info->par; + gp->info = info; + gp->of_node = dp; + + gp->fb_base_phys = op->resource[6].start; + + err = gfb_get_props(gp); + if (err) + goto err_release_fb; + + /* Framebuffer length is the same regardless of resolution. */ + info->fix.line_length = 16384; + gp->fb_size = info->fix.line_length * gp->height; + + gp->fb_base = of_ioremap(&op->resource[6], 0, + gp->fb_size, "gfb fb"); + if (!gp->fb_base) { + err = -ENOMEM; + goto err_release_fb; + } + + err = gfb_set_fbinfo(gp); + if (err) + goto err_unmap_fb; + + printk("gfb: Found device at %pOF\n", dp); + + err = register_framebuffer(info); + if (err < 0) { + printk(KERN_ERR "gfb: Could not register framebuffer %pOF\n", + dp); + goto err_unmap_fb; + } + + dev_set_drvdata(&op->dev, info); + + return 0; + +err_unmap_fb: + of_iounmap(&op->resource[6], gp->fb_base, gp->fb_size); + +err_release_fb: + framebuffer_release(info); + +err_out: + return err; +} + +static const struct of_device_id gfb_match[] = { + { + .name = "SUNW,gfb", + }, + {}, +}; + +static struct platform_driver gfb_driver = { + .probe = gfb_probe, + .driver = { + .name = "gfb", + .of_match_table = gfb_match, + .suppress_bind_attrs = true, + }, +}; + +static int __init gfb_init(void) +{ + if (fb_get_options("gfb", NULL)) + return -ENODEV; + + return platform_driver_register(&gfb_driver); +} +device_initcall(gfb_init); -- cgit v1.3.1