Re: [linux-next:master 9793/10134] drivers/of/of_reserved_mem.c:463 fdt_init_reserved_mem() error: uninitialized symbol 'nomap'.

[Oreoluwa Babatunde <quic_obabatun@quicinc.com>]

On 5/2/2024 1:45 AM, Dan Carpenter wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   f68868ba718e30594165879cc3020607165b0761
> commit: 2acef04ad57cab44b33001542791fc93f81cadf1 [9793/10134] of: reserved_mem: Remove the use of phandle from the reserved_mem APIs
> config: i386-randconfig-141-20240501 (https://download.01.org/0day-ci/archive/20240502/202405020127.3ncxx3EI-lkp@intel.com/config)
> compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> | Closes: https://lore.kernel.org/r/202405020127.3ncxx3EI-lkp@intel.com/
>
> smatch warnings:
> drivers/of/of_reserved_mem.c:463 fdt_init_reserved_mem() error: uninitialized symbol 'nomap'.
>
> vim +/nomap +463 drivers/of/of_reserved_mem.c
>
> 3f0c8206644836 Marek Szyprowski   2014-02-28  430  void __init fdt_init_reserved_mem(void)
> 3f0c8206644836 Marek Szyprowski   2014-02-28  431  {
> 3f0c8206644836 Marek Szyprowski   2014-02-28  432  	int i;
> ae1add247bf8c2 Mitchel Humpherys  2015-09-15  433  
> ae1add247bf8c2 Mitchel Humpherys  2015-09-15  434  	/* check for overlapping reserved regions */
> ae1add247bf8c2 Mitchel Humpherys  2015-09-15  435  	__rmem_check_for_overlap();
> ae1add247bf8c2 Mitchel Humpherys  2015-09-15  436  
> 3f0c8206644836 Marek Szyprowski   2014-02-28  437  	for (i = 0; i < reserved_mem_count; i++) {
> 3f0c8206644836 Marek Szyprowski   2014-02-28  438  		struct reserved_mem *rmem = &reserved_mem[i];
> 3f0c8206644836 Marek Szyprowski   2014-02-28  439  		unsigned long node = rmem->fdt_node;
> 3f0c8206644836 Marek Szyprowski   2014-02-28  440  		int err = 0;
> 6f1188b4ac7577 Yue Hu             2020-07-30  441  		bool nomap;
> 3f0c8206644836 Marek Szyprowski   2014-02-28  442  
> 3f0c8206644836 Marek Szyprowski   2014-02-28  443  		if (rmem->size == 0)
> 3f0c8206644836 Marek Szyprowski   2014-02-28  444  			err = __reserved_mem_alloc_size(node, rmem->name,
> 3f0c8206644836 Marek Szyprowski   2014-02-28  445  						 &rmem->base, &rmem->size);
> d0b8ed47e83a22 pierre Kuo         2019-02-19  446  		if (err == 0) {
> d0b8ed47e83a22 pierre Kuo         2019-02-19  447  			err = __reserved_mem_init_node(rmem);
> d0b8ed47e83a22 pierre Kuo         2019-02-19  448  			if (err != 0 && err != -ENOENT) {
> d0b8ed47e83a22 pierre Kuo         2019-02-19  449  				pr_info("node %s compatible matching fail\n",
> d0b8ed47e83a22 pierre Kuo         2019-02-19  450  					rmem->name);
> 2acef04ad57cab Oreoluwa Babatunde 2024-04-22  451  
> 2acef04ad57cab Oreoluwa Babatunde 2024-04-22  452  				nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
> d0b8ed47e83a22 pierre Kuo         2019-02-19  453  				if (nomap)
> 7b25995f5319ad Dong Aisheng       2021-06-11  454  					memblock_clear_nomap(rmem->base, rmem->size);
> 3c6867a12a224d Dong Aisheng       2021-06-11  455  				else
> 3ecc68349bbab6 Mike Rapoport      2021-11-05  456  					memblock_phys_free(rmem->base,
> 3ecc68349bbab6 Mike Rapoport      2021-11-05  457  							   rmem->size);
> aeb9267eb6b1df Martin Liu         2023-02-10  458  			} else {
> aeb9267eb6b1df Martin Liu         2023-02-10  459  				phys_addr_t end = rmem->base + rmem->size - 1;
> aeb9267eb6b1df Martin Liu         2023-02-10  460  				bool reusable =
> aeb9267eb6b1df Martin Liu         2023-02-10  461  					(of_get_flat_dt_prop(node, "reusable", NULL)) != NULL;
> aeb9267eb6b1df Martin Liu         2023-02-10  462  
> 6ee7afbabcee4d Geert Uytterhoeven 2023-02-16 @463  				pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
> aeb9267eb6b1df Martin Liu         2023-02-10  464  					&rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
> aeb9267eb6b1df Martin Liu         2023-02-10  465  					nomap ? "nomap" : "map",
>                                                                                         ^^^^^    ^^^^^
> This is nomap from the previous iteration through the loop.  How is
> it useful?
Hi Dan,

I have uploaded a new patch which has the correct behavior
for nomap in this loop.
https://lore.kernel.org/all/20240502192403.3307277-1-quic_obabatun@quicinc.com/

Moving line 452 into the if statement was an error on my
part because I did not take note that the value was being
printed in the else statement as well.

Thank you!

Oreoluwa