Le 25/02/2019 à 19:57, Dave Hansen a écrit :
From: Dave Hansen <[email protected]> walk_system_ram_range() can return an error code either becuase *it* failed, or because the 'func' that it calls returned an error. The memory hotplug does the following: ret = walk_system_ram_range(..., func); if (ret) return ret; and 'ret' makes it out to userspace, eventually. The problem s, walk_system_ram_range() failues that result from *it* failing (as opposed to 'func') return -1. That leads to a very odd -EPERM (-1) return code out to userspace. Make walk_system_ram_range() return -EINVAL for internal failures to keep userspace less confused. This return code is compatible with all the callers that I audited. This changes both the generic mm/ and powerpc-specific implementations to have the same return value. Signed-off-by: Dave Hansen <[email protected]> Reviewed-by: Bjorn Helgaas <[email protected]> Acked-by: Michael Ellerman <[email protected]> (powerpc) Cc: Dan Williams <[email protected]> Cc: Dave Jiang <[email protected]> Cc: Ross Zwisler <[email protected]> Cc: Vishal Verma <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Michal Hocko <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Huang Ying <[email protected]> Cc: Fengguang Wu <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Yaowei Bai <[email protected]> Cc: Takashi Iwai <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: [email protected] Cc: Keith Busch <[email protected]> --- b/arch/powerpc/mm/mem.c | 2 +-
walk_system_ram_range() was droped in commit https://git.kernel.orghttps://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=26b523356f49a0117c8f9e32ca98aa6d6e496e1a
Christophe
b/kernel/resource.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff -puN arch/powerpc/mm/mem.c~memory-hotplug-walk_system_ram_range-returns-neg-1 arch/powerpc/mm/mem.c --- a/arch/powerpc/mm/mem.c~memory-hotplug-walk_system_ram_range-returns-neg-1 2019-02-25 10:56:47.452908034 -0800 +++ b/arch/powerpc/mm/mem.c 2019-02-25 10:56:47.458908034 -0800 @@ -189,7 +189,7 @@ walk_system_ram_range(unsigned long star struct memblock_region *reg; unsigned long end_pfn = start_pfn + nr_pages; unsigned long tstart, tend; - int ret = -1; + int ret = -EINVAL;for_each_memblock(memory, reg) {tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); diff -puN kernel/resource.c~memory-hotplug-walk_system_ram_range-returns-neg-1 kernel/resource.c --- a/kernel/resource.c~memory-hotplug-walk_system_ram_range-returns-neg-1 2019-02-25 10:56:47.454908034 -0800 +++ b/kernel/resource.c 2019-02-25 10:56:47.459908034 -0800 @@ -382,7 +382,7 @@ static int __walk_iomem_res_desc(resourc int (*func)(struct resource *, void *)) { struct resource res; - int ret = -1; + int ret = -EINVAL;while (start < end &&!find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) { @@ -462,7 +462,7 @@ int walk_system_ram_range(unsigned long unsigned long flags; struct resource res; unsigned long pfn, end_pfn; - int ret = -1; + int ret = -EINVAL;start = (u64) start_pfn << PAGE_SHIFT;end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; _
