On Fri, Sep 7, 2018 at 8:55 PM Paul Burton paul.burton@mips.com wrote:
Commit 8ce355cf2e38 ("MIPS: Setup boot_command_line before plat_mem_setup") fixed a problem for systems which have CONFIG_CMDLINE_BOOL=y & use a DT with a chosen node that has either no bootargs property or an empty one. In this configuration early_init_dt_scan_chosen() copies CONFIG_CMDLINE into boot_command_line, but the MIPS code doesn't know this so it appends CONFIG_CMDLINE (via builtin_cmdline) to boot_command_line again. The result is that boot_command_line contains the arguments from CONFIG_CMDLINE twice.
That commit took the approach of simply setting up boot_command_line from the MIPS code before early_init_dt_scan_chosen() runs, causing it not to copy CONFIG_CMDLINE to boot_command_line if a chosen node with no bootargs property is found.
Unfortunately this is problematic for systems which do have a non-empty bootargs property & CONFIG_CMDLINE_BOOL=y. There early_init_dt_scan_chosen() will overwrite boot_command_line with the arguments from DT, which means we lose those from CONFIG_CMDLINE entirely. This breaks CONFIG_MIPS_CMDLINE_DTB_EXTEND. If we have CONFIG_MIPS_CMDLINE_FROM_BOOTLOADER or CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND selected and the DT has a bootargs property which we should ignore, it will instead be honoured breaking those configurations too.
Fix this by reverting commit 8ce355cf2e38 ("MIPS: Setup boot_command_line before plat_mem_setup") to restore the former behaviour, and fixing the CONFIG_CMDLINE duplication issue by instead providing a no-op implementation of early_init_dt_fixup_cmdline_arch() to prevent early_init_dt_scan_chosen() from using CONFIG_CMDLINE.
Sorry I cannot test this patch ATM. I've simply CCed Paul C. just in case.
Signed-off-by: Paul Burton paul.burton@mips.com Fixes: 8ce355cf2e38 ("MIPS: Setup boot_command_line before plat_mem_setup") References: https://patchwork.linux-mips.org/patch/18804/ Cc: Frank Rowand frowand.list@gmail.com Cc: Jaedon Shin jaedon.shin@gmail.com Cc: Mathieu Malaterre malat@debian.org Cc: Rob Herring robh+dt@kernel.org Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.16+
arch/mips/kernel/setup.c | 47 +++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 20 deletions(-)
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index c71d1eb7da59..7f755bc8a91c 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -841,11 +841,38 @@ static void __init request_crashkernel(struct resource *res) #define BUILTIN_EXTEND_WITH_PROM \ IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND)
+void __init early_init_dt_fixup_cmdline_arch(char *data) +{
/** Do nothing - arch_mem_init() will assemble our command line below,* for both the DT & non-DT cases.*/+}
static void __init arch_mem_init(char **cmdline_p) { struct memblock_region *reg; extern void plat_mem_setup(void);
/* call board setup routine */plat_mem_setup();/** Make sure all kernel memory is in the maps. The "UP" and* "DOWN" are opposite for initdata since if it crosses over* into another memory section you don't want that to be* freed when the initdata is freed.*/arch_mem_addpart(PFN_DOWN(__pa_symbol(&_text)) << PAGE_SHIFT,PFN_UP(__pa_symbol(&_edata)) << PAGE_SHIFT,BOOT_MEM_RAM);arch_mem_addpart(PFN_UP(__pa_symbol(&__init_begin)) << PAGE_SHIFT,PFN_DOWN(__pa_symbol(&__init_end)) << PAGE_SHIFT,BOOT_MEM_INIT_RAM);pr_info("Determined physical RAM map:\n");print_memory_map();#if defined(CONFIG_CMDLINE_BOOL) && defined(CONFIG_CMDLINE_OVERRIDE) strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); #else @@ -873,26 +900,6 @@ static void __init arch_mem_init(char **cmdline_p) } #endif #endif
/* call board setup routine */plat_mem_setup();/** Make sure all kernel memory is in the maps. The "UP" and* "DOWN" are opposite for initdata since if it crosses over* into another memory section you don't want that to be* freed when the initdata is freed.*/arch_mem_addpart(PFN_DOWN(__pa_symbol(&_text)) << PAGE_SHIFT,PFN_UP(__pa_symbol(&_edata)) << PAGE_SHIFT,BOOT_MEM_RAM);arch_mem_addpart(PFN_UP(__pa_symbol(&__init_begin)) << PAGE_SHIFT,PFN_DOWN(__pa_symbol(&__init_end)) << PAGE_SHIFT,BOOT_MEM_INIT_RAM);pr_info("Determined physical RAM map:\n");print_memory_map();strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); *cmdline_p = command_line;-- 2.18.0