| Message ID | 20170903120757.14968-24-ard.biesheuvel@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, 3 Sep 2017, Ard Biesheuvel wrote: > The location of swapper_pg_dir is relative to the kernel, not to > PAGE_OFFSET or PHYS_OFFSET. So define the symbol relative to the > start of the kernel image, and refer to it via its name. Could it cause a section access mismatch if defined in the __HEAD section? Otherwise Acked-by: Nicolas Pitre <nico@linaro.org> > > Cc: Russell King <linux@armlinux.org.uk> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > arch/arm/kernel/head.S | 13 ++++--------- > 1 file changed, 4 insertions(+), 9 deletions(-) > > diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S > index 5d685e86148c..71bc0d037bc9 100644 > --- a/arch/arm/kernel/head.S > +++ b/arch/arm/kernel/head.S > @@ -48,14 +48,6 @@ > #define PMD_ORDER 2 > #endif > > - .globl swapper_pg_dir > - .equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE > - > - .macro pgtbl, rd, phys > - add \rd, \phys, #TEXT_OFFSET > - sub \rd, \rd, #PG_DIR_SIZE > - .endm > - > /* > * Kernel startup entry point. > * --------------------------- > @@ -77,6 +69,9 @@ > .arm > > __HEAD > + .globl swapper_pg_dir > + .equ swapper_pg_dir, . - PG_DIR_SIZE > + > ENTRY(stext) > ARM_BE8(setend be ) @ ensure we are in BE8 mode > > @@ -172,7 +167,7 @@ ENDPROC(stext) > * r4 = physical page table address > */ > __create_page_tables: > - pgtbl r4, r8 @ page table address > + adr_l r4, swapper_pg_dir @ page table address > > /* > * Clear the swapper page table > -- > 2.11.0 > >
On 4 September 2017 at 19:30, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > On Sun, 3 Sep 2017, Ard Biesheuvel wrote: > >> The location of swapper_pg_dir is relative to the kernel, not to >> PAGE_OFFSET or PHYS_OFFSET. So define the symbol relative to the >> start of the kernel image, and refer to it via its name. > > Could it cause a section access mismatch if defined in the __HEAD > section? > No, I never saw any mismatch warnings building this code, and I don't think .head.text is treated as an __init section. > Otherwise > > Acked-by: Nicolas Pitre <nico@linaro.org> > Thanks >> >> Cc: Russell King <linux@armlinux.org.uk> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> --- >> arch/arm/kernel/head.S | 13 ++++--------- >> 1 file changed, 4 insertions(+), 9 deletions(-) >> >> diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S >> index 5d685e86148c..71bc0d037bc9 100644 >> --- a/arch/arm/kernel/head.S >> +++ b/arch/arm/kernel/head.S >> @@ -48,14 +48,6 @@ >> #define PMD_ORDER 2 >> #endif >> >> - .globl swapper_pg_dir >> - .equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE >> - >> - .macro pgtbl, rd, phys >> - add \rd, \phys, #TEXT_OFFSET >> - sub \rd, \rd, #PG_DIR_SIZE >> - .endm >> - >> /* >> * Kernel startup entry point. >> * --------------------------- >> @@ -77,6 +69,9 @@ >> .arm >> >> __HEAD >> + .globl swapper_pg_dir >> + .equ swapper_pg_dir, . - PG_DIR_SIZE >> + >> ENTRY(stext) >> ARM_BE8(setend be ) @ ensure we are in BE8 mode >> >> @@ -172,7 +167,7 @@ ENDPROC(stext) >> * r4 = physical page table address >> */ >> __create_page_tables: >> - pgtbl r4, r8 @ page table address >> + adr_l r4, swapper_pg_dir @ page table address >> >> /* >> * Clear the swapper page table >> -- >> 2.11.0 >> >>
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 5d685e86148c..71bc0d037bc9 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -48,14 +48,6 @@ #define PMD_ORDER 2 #endif - .globl swapper_pg_dir - .equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE - - .macro pgtbl, rd, phys - add \rd, \phys, #TEXT_OFFSET - sub \rd, \rd, #PG_DIR_SIZE - .endm - /* * Kernel startup entry point. * --------------------------- @@ -77,6 +69,9 @@ .arm __HEAD + .globl swapper_pg_dir + .equ swapper_pg_dir, . - PG_DIR_SIZE + ENTRY(stext) ARM_BE8(setend be ) @ ensure we are in BE8 mode @@ -172,7 +167,7 @@ ENDPROC(stext) * r4 = physical page table address */ __create_page_tables: - pgtbl r4, r8 @ page table address + adr_l r4, swapper_pg_dir @ page table address /* * Clear the swapper page table
The location of swapper_pg_dir is relative to the kernel, not to PAGE_OFFSET or PHYS_OFFSET. So define the symbol relative to the start of the kernel image, and refer to it via its name. Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/kernel/head.S | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-)