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    Subject[PATCH 5.16 0463/1039] powerpc/modules: Dont WARN on first module allocation attempt
    Date
    From: Christophe Leroy <christophe.leroy@csgroup.eu>

    [ Upstream commit f1797e4de1146009c888bcf8b6bb6648d55394f1 ]

    module_alloc() first tries to allocate module text within 24 bits direct
    jump from kernel text, and tries a wider allocation if first one fails.

    When first allocation fails the following is observed in kernel logs:

    vmap allocation for size 2400256 failed: use vmalloc=<size> to increase size
    systemd-udevd: vmalloc error: size 2395133, vm_struct allocation failed, mode:0xcc0(GFP_KERNEL), nodemask=(null)
    CPU: 0 PID: 127 Comm: systemd-udevd Tainted: G W 5.15.5-gentoo-PowerMacG4 #9
    Call Trace:
    [e2a53a50] [c0ba0048] dump_stack_lvl+0x80/0xb0 (unreliable)
    [e2a53a70] [c0540128] warn_alloc+0x11c/0x2b4
    [e2a53b50] [c0531be8] __vmalloc_node_range+0xd8/0x64c
    [e2a53c10] [c00338c0] module_alloc+0xa0/0xac
    [e2a53c40] [c027a368] load_module+0x2ae0/0x8148
    [e2a53e30] [c027fc78] sys_finit_module+0xfc/0x130
    [e2a53f30] [c0035098] ret_from_syscall+0x0/0x28
    ...

    Add __GFP_NOWARN flag to first allocation so that no warning appears
    when it fails.

    Reported-by: Erhard Furtner <erhard_f@mailbox.org>
    Fixes: 2ec13df16704 ("powerpc/modules: Load modules closer to kernel text")
    Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
    Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
    Link: https://lore.kernel.org/r/93c9b84d6ec76aaf7b4f03468e22433a6d308674.1638267035.git.christophe.leroy@csgroup.eu
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    arch/powerpc/kernel/module.c | 11 ++++++-----
    1 file changed, 6 insertions(+), 5 deletions(-)

    diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
    index ed04a3ba66fe8..40a583e9d3c70 100644
    --- a/arch/powerpc/kernel/module.c
    +++ b/arch/powerpc/kernel/module.c
    @@ -90,16 +90,17 @@ int module_finalize(const Elf_Ehdr *hdr,
    }

    static __always_inline void *
    -__module_alloc(unsigned long size, unsigned long start, unsigned long end)
    +__module_alloc(unsigned long size, unsigned long start, unsigned long end, bool nowarn)
    {
    pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
    + gfp_t gfp = GFP_KERNEL | (nowarn ? __GFP_NOWARN : 0);

    /*
    * Don't do huge page allocations for modules yet until more testing
    * is done. STRICT_MODULE_RWX may require extra work to support this
    * too.
    */
    - return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL, prot,
    + return __vmalloc_node_range(size, 1, start, end, gfp, prot,
    VM_FLUSH_RESET_PERMS | VM_NO_HUGE_VMAP,
    NUMA_NO_NODE, __builtin_return_address(0));
    }
    @@ -114,13 +115,13 @@ void *module_alloc(unsigned long size)

    /* First try within 32M limit from _etext to avoid branch trampolines */
    if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit)
    - ptr = __module_alloc(size, limit, MODULES_END);
    + ptr = __module_alloc(size, limit, MODULES_END, true);

    if (!ptr)
    - ptr = __module_alloc(size, MODULES_VADDR, MODULES_END);
    + ptr = __module_alloc(size, MODULES_VADDR, MODULES_END, false);

    return ptr;
    #else
    - return __module_alloc(size, VMALLOC_START, VMALLOC_END);
    + return __module_alloc(size, VMALLOC_START, VMALLOC_END, false);
    #endif
    }
    --
    2.34.1


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