Messages in this thread | | | From | Song Shuai <> | Date | Wed, 2 Aug 2023 01:05:23 +0000 | Subject | Re: [PATCH] riscv: Correct the MODULES_VADDR |
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Guo Ren <guoren@kernel.org> 于2023年8月1日周二 23:20写道: > > On Tue, Aug 1, 2023 at 8:05 AM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: > > > > Hi Song, > > > > On Tue, Aug 1, 2023 at 1:10 PM Song Shuai <suagrfillet@gmail.com> wrote: > > > > > > As Documentation/riscv/vm-layout.rst describes, the 2G-sized "modules, BPF" > > > area should lie right before the "kernel" area. But the current definition > > > of MODULES_VADDR isn't consistent with that, so correct it. > > > > > > Before this patch, the size of "modules" from print_vm_layout() is not 2G. > > > > > > [ 0.000000] modules : 0xffffffff2ff2f000 - 0xffffffffae600000 (2022 MB) > > > [ 0.000000] lowmem : 0xff60000000000000 - 0xff60000040000000 (1024 MB) > > > [ 0.000000] kernel : 0xffffffffae600000 - 0xffffffffffffffff (1305 MB) > > > > > > After this patch, the size is 2G. > > > > > > [ 0.000000] modules : 0xffffffff3a000000 - 0xffffffffba000000 (2048 MB) > > > [ 0.000000] lowmem : 0xff60000000000000 - 0xff60000040000000 (1024 MB) > > > [ 0.000000] kernel : 0xffffffffba000000 - 0xffffffffffffffff (1119 MB) > > > > > > Signed-off-by: Song Shuai <suagrfillet@gmail.com> > > > --- > > > arch/riscv/include/asm/pgtable.h | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > > > index 75970ee2bda2..7c57e17fc758 100644 > > > --- a/arch/riscv/include/asm/pgtable.h > > > +++ b/arch/riscv/include/asm/pgtable.h > > > @@ -53,8 +53,8 @@ > > > #ifdef CONFIG_64BIT > > > /* This is used to define the end of the KASAN shadow region */ > > > #define MODULES_LOWEST_VADDR (KERNEL_LINK_ADDR - SZ_2G) > > > -#define MODULES_VADDR (PFN_ALIGN((unsigned long)&_end) - SZ_2G) > > > #define MODULES_END (PFN_ALIGN((unsigned long)&_start)) > > > +#define MODULES_VADDR (MODULES_END - SZ_2G) > > > #endif > > > > > > /* > > > -- > > > 2.20.1 > > > > > > > The documentation is approximative, the modules must stay within a 2GB > > window to *all* the kernel symbols, hence the __end - 2G, not __start. > Thus, the ftrace detour trampoline could cover all kernel symbols. > That's another view to help me understand the definition of MODULES_VADDR,Thanks. > -- > Best Regards > Guo Ren
-- Thanks, Song
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