Message ID | cover.1628670468.git.geert+renesas@glider.be |
---|---|
Headers | show |
Series | Add generic support for kdump DT properties | expand |
On Wed, Aug 11, 2021 at 10:51 AM Geert Uytterhoeven <geert+renesas@glider.be> wrote: > Prepare for early_init_fdt_scan_reserved_mem() reserving the memory > occupied by an elf core header described in the device tree. > As arch_mem_init() calls early_init_fdt_scan_reserved_mem() before > mips_reserve_vmcore(), the latter needs to check if the memory has > already been reserved before. > > Note that mips_reserve_vmcore() cannot just be removed, as not all MIPS > systems use DT. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > v5: > - New. > --- > arch/mips/kernel/setup.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > index 23a140327a0bac1b..4693add05743d78b 100644 > --- a/arch/mips/kernel/setup.c > +++ b/arch/mips/kernel/setup.c > @@ -429,7 +429,8 @@ static void __init mips_reserve_vmcore(void) > pr_info("Reserving %ldKB of memory at %ldKB for kdump\n", > (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10); > > - memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > + if (!memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size) As pointed out by lkp, there's a closing parenthesis missing. /me hides back under his rock. > + memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > #endif Gr{oetje,eeting}s, Geert
On Wed, Aug 11, 2021 at 10:50:58AM +0200, Geert Uytterhoeven wrote: > Hi all, > > This patch series adds generic support for parsing DT properties related > to crash dump kernels ("linux,elfcorehdr" and "linux,elfcorehdr" under > the "/chosen" node), makes use of it on arm32, and performs a few > cleanups. It is an evolution of the combination of [1] and [2]. The DT bits look fine to me. How do you expect this to be merged? I'm happy to take it if arch maintainers can ack it. > > The series consists of 6 parts: > 1. Patch 1 prepares architecture-specific code (needed for MIPS only) > to avoid duplicating elf core header reservation later. > 2. Patch 2 prepares the visibility of variables used to hold > information retrieved from the DT properties. > 3. Patches 3-5 add support to the FDT core for handling the > properties. > This can co-exist safely with architecture-specific handling, until > the latter has been removed. Looks like patch 5 doesn't have any dependencies with the series? > 4. Patch 6 removes the non-standard handling of "linux,elfcorehdr" on > riscv. I thought this should be applied for 5.14? > 5. Patches 7-8 convert arm64 to use the generic handling instead of > its own implementation. > 6. Patch 9 adds support for kdump properties to arm32. > The corresponding patch for kexec-tools is "[PATCH] arm: kdump: Add > DT properties to crash dump kernel's DTB"[3], which is still valid. This one can be applied on its own, right? Rob
Hi Geert, On Wed, Aug 11, 2021 at 10:50:59AM +0200, Geert Uytterhoeven wrote: > Prepare for early_init_fdt_scan_reserved_mem() reserving the memory > occupied by an elf core header described in the device tree. > As arch_mem_init() calls early_init_fdt_scan_reserved_mem() before > mips_reserve_vmcore(), the latter needs to check if the memory has > already been reserved before. Doing memblock_reserve() for the same region is usually fine, did you encounter any issues without this patch? > Note that mips_reserve_vmcore() cannot just be removed, as not all MIPS > systems use DT. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > v5: > - New. > --- > arch/mips/kernel/setup.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > index 23a140327a0bac1b..4693add05743d78b 100644 > --- a/arch/mips/kernel/setup.c > +++ b/arch/mips/kernel/setup.c > @@ -429,7 +429,8 @@ static void __init mips_reserve_vmcore(void) > pr_info("Reserving %ldKB of memory at %ldKB for kdump\n", > (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10); > > - memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > + if (!memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size) > + memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > #endif > } > > -- > 2.25.1 > -- Sincerely yours, Mike.
Hi Rob, On Sun, Aug 15, 2021 at 5:25 PM Rob Herring <robh@kernel.org> wrote: > On Wed, Aug 11, 2021 at 10:50:58AM +0200, Geert Uytterhoeven wrote: > > This patch series adds generic support for parsing DT properties related > > to crash dump kernels ("linux,elfcorehdr" and "linux,elfcorehdr" under > > the "/chosen" node), makes use of it on arm32, and performs a few > > cleanups. It is an evolution of the combination of [1] and [2]. > > The DT bits look fine to me. How do you expect this to be merged? I'm > happy to take it if arch maintainers can ack it. I had hoped you could take the series... > > The series consists of 6 parts: > > 1. Patch 1 prepares architecture-specific code (needed for MIPS only) > > to avoid duplicating elf core header reservation later. > > 2. Patch 2 prepares the visibility of variables used to hold > > information retrieved from the DT properties. > > 3. Patches 3-5 add support to the FDT core for handling the > > properties. > > This can co-exist safely with architecture-specific handling, until > > the latter has been removed. > > Looks like patch 5 doesn't have any dependencies with the series? Indeed. So you can take it independently. > > 4. Patch 6 removes the non-standard handling of "linux,elfcorehdr" on > > riscv. > > I thought this should be applied for 5.14? Me too, but unfortunately that hasn't happened yet... > > 5. Patches 7-8 convert arm64 to use the generic handling instead of > > its own implementation. > > 6. Patch 9 adds support for kdump properties to arm32. > > The corresponding patch for kexec-tools is "[PATCH] arm: kdump: Add > > DT properties to crash dump kernel's DTB"[3], which is still valid. > > This one can be applied on its own, right? While that wouldn't break anything (i.e. no regression), it still wouldn't work if the DT properties are present, and the now-legacy "mem=" kernel command line parameter is not. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Hi Mike, On Mon, Aug 16, 2021 at 7:52 AM Mike Rapoport <rppt@kernel.org> wrote: > On Wed, Aug 11, 2021 at 10:50:59AM +0200, Geert Uytterhoeven wrote: > > Prepare for early_init_fdt_scan_reserved_mem() reserving the memory > > occupied by an elf core header described in the device tree. > > As arch_mem_init() calls early_init_fdt_scan_reserved_mem() before > > mips_reserve_vmcore(), the latter needs to check if the memory has > > already been reserved before. > > Doing memblock_reserve() for the same region is usually fine, did you > encounter any issues without this patch? Does it also work if the same region is part of an earlier larger reservation? I am no memblock expert, so I don't know. I didn't run into any issues, as my MIPS platform is non-DT, but I assume arch/arm64/mm/init.c:reserve_elfcorehdr() had the check for a reason. Thanks! > > > Note that mips_reserve_vmcore() cannot just be removed, as not all MIPS > > systems use DT. > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > > --- > > v5: > > - New. > > --- > > arch/mips/kernel/setup.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > > index 23a140327a0bac1b..4693add05743d78b 100644 > > --- a/arch/mips/kernel/setup.c > > +++ b/arch/mips/kernel/setup.c > > @@ -429,7 +429,8 @@ static void __init mips_reserve_vmcore(void) > > pr_info("Reserving %ldKB of memory at %ldKB for kdump\n", > > (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10); > > > > - memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > > + if (!memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size) > > + memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > > #endif > > } Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Wed, Aug 11, 2021 at 10:51:05AM +0200, Geert Uytterhoeven wrote: > Remove the architecture-specific code for handling the > "linux,elfcorehdr" property under the "/chosen" node in DT, as the > platform-agnostic handling in the FDT core code already takes care of > this. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
On Wed, Aug 11, 2021 at 10:51:06AM +0200, Geert Uytterhoeven wrote: > Remove the architecture-specific code for handling the > "linux,usable-memory-range" property under the "/chosen" node in DT, as > the platform-agnostic FDT core code already takes care of this. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
On Mon, Aug 23, 2021 at 12:17:50PM +0200, Geert Uytterhoeven wrote: > Hi Mike, > > On Mon, Aug 16, 2021 at 7:52 AM Mike Rapoport <rppt@kernel.org> wrote: > > On Wed, Aug 11, 2021 at 10:50:59AM +0200, Geert Uytterhoeven wrote: > > > Prepare for early_init_fdt_scan_reserved_mem() reserving the memory > > > occupied by an elf core header described in the device tree. > > > As arch_mem_init() calls early_init_fdt_scan_reserved_mem() before > > > mips_reserve_vmcore(), the latter needs to check if the memory has > > > already been reserved before. > > > > Doing memblock_reserve() for the same region is usually fine, did you > > encounter any issues without this patch? > > Does it also work if the same region is part of an earlier larger > reservation? I am no memblock expert, so I don't know. > I didn't run into any issues, as my MIPS platform is non-DT, but I > assume arch/arm64/mm/init.c:reserve_elfcorehdr() had the check for > a reason. The memory will be reserved regardless of the earlier reservation, the issue may appear when the reservations are made for different purpose. E.g. if there was crash kernel allocation before the reservation of elfcorehdr. The check in such case will prevent the second reservation, but, at least in arch/arm64/mm/init.c:reserve_elfcorehdr() it does not seem to prevent different users of the overlapping regions to step on each others toes. Moreover, arm64::reserve_elfcorehdr() seems buggy to me, because of there is only a partial overlap of the elfcorehdr with the previous reservation, the non-overlapping part of elfcorehdr won't get reserved at all. > Thanks! > > > > > > Note that mips_reserve_vmcore() cannot just be removed, as not all MIPS > > > systems use DT. > > > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > > > --- > > > v5: > > > - New. > > > --- > > > arch/mips/kernel/setup.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > > > index 23a140327a0bac1b..4693add05743d78b 100644 > > > --- a/arch/mips/kernel/setup.c > > > +++ b/arch/mips/kernel/setup.c > > > @@ -429,7 +429,8 @@ static void __init mips_reserve_vmcore(void) > > > pr_info("Reserving %ldKB of memory at %ldKB for kdump\n", > > > (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10); > > > > > > - memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > > > + if (!memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size) > > > + memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > > > #endif > > > } > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds -- Sincerely yours, Mike.
On Mon, Aug 23, 2021 at 8:10 AM Mike Rapoport <rppt@kernel.org> wrote: > > On Mon, Aug 23, 2021 at 12:17:50PM +0200, Geert Uytterhoeven wrote: > > Hi Mike, > > > > On Mon, Aug 16, 2021 at 7:52 AM Mike Rapoport <rppt@kernel.org> wrote: > > > On Wed, Aug 11, 2021 at 10:50:59AM +0200, Geert Uytterhoeven wrote: > > > > Prepare for early_init_fdt_scan_reserved_mem() reserving the memory > > > > occupied by an elf core header described in the device tree. > > > > As arch_mem_init() calls early_init_fdt_scan_reserved_mem() before > > > > mips_reserve_vmcore(), the latter needs to check if the memory has > > > > already been reserved before. > > > > > > Doing memblock_reserve() for the same region is usually fine, did you > > > encounter any issues without this patch? > > > > Does it also work if the same region is part of an earlier larger > > reservation? I am no memblock expert, so I don't know. > > I didn't run into any issues, as my MIPS platform is non-DT, but I > > assume arch/arm64/mm/init.c:reserve_elfcorehdr() had the check for > > a reason. > > The memory will be reserved regardless of the earlier reservation, the > issue may appear when the reservations are made for different purpose. E.g. > if there was crash kernel allocation before the reservation of elfcorehdr. > > The check in such case will prevent the second reservation, but, at least > in arch/arm64/mm/init.c:reserve_elfcorehdr() it does not seem to prevent > different users of the overlapping regions to step on each others toes. If the kernel has been passed in overlapping regions, is there anything you can do other than hope to get a message out? > Moreover, arm64::reserve_elfcorehdr() seems buggy to me, because of there > is only a partial overlap of the elfcorehdr with the previous reservation, > the non-overlapping part of elfcorehdr won't get reserved at all. What do you suggest as the arm64 version is not the common version? Rob
On Mon, Aug 23, 2021 at 5:13 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > Hi Rob, > > On Sun, Aug 15, 2021 at 5:25 PM Rob Herring <robh@kernel.org> wrote: > > On Wed, Aug 11, 2021 at 10:50:58AM +0200, Geert Uytterhoeven wrote: > > > This patch series adds generic support for parsing DT properties related > > > to crash dump kernels ("linux,elfcorehdr" and "linux,elfcorehdr" under > > > the "/chosen" node), makes use of it on arm32, and performs a few > > > cleanups. It is an evolution of the combination of [1] and [2]. > > > > The DT bits look fine to me. How do you expect this to be merged? I'm > > happy to take it if arch maintainers can ack it. > > I had hoped you could take the series... My current thought is I'll take 2-5, 7 and 8 given that's what I have acks for and the others can be applied independently. > > > The series consists of 6 parts: > > > 1. Patch 1 prepares architecture-specific code (needed for MIPS only) > > > to avoid duplicating elf core header reservation later. > > > 2. Patch 2 prepares the visibility of variables used to hold > > > information retrieved from the DT properties. > > > 3. Patches 3-5 add support to the FDT core for handling the > > > properties. > > > This can co-exist safely with architecture-specific handling, until > > > the latter has been removed. > > > > Looks like patch 5 doesn't have any dependencies with the series? > > Indeed. So you can take it independently. > > > > 4. Patch 6 removes the non-standard handling of "linux,elfcorehdr" on > > > riscv. > > > > I thought this should be applied for 5.14? > > Me too, but unfortunately that hasn't happened yet... Buried in the middle of this series is not going to encourage it to be picked up as a fix. Rob
On Mon, Aug 23, 2021 at 09:44:55AM -0500, Rob Herring wrote: > On Mon, Aug 23, 2021 at 8:10 AM Mike Rapoport <rppt@kernel.org> wrote: > > > > On Mon, Aug 23, 2021 at 12:17:50PM +0200, Geert Uytterhoeven wrote: > > > Hi Mike, > > > > > > On Mon, Aug 16, 2021 at 7:52 AM Mike Rapoport <rppt@kernel.org> wrote: > > > > On Wed, Aug 11, 2021 at 10:50:59AM +0200, Geert Uytterhoeven wrote: > > > > > Prepare for early_init_fdt_scan_reserved_mem() reserving the memory > > > > > occupied by an elf core header described in the device tree. > > > > > As arch_mem_init() calls early_init_fdt_scan_reserved_mem() before > > > > > mips_reserve_vmcore(), the latter needs to check if the memory has > > > > > already been reserved before. > > > > > > > > Doing memblock_reserve() for the same region is usually fine, did you > > > > encounter any issues without this patch? > > > > > > Does it also work if the same region is part of an earlier larger > > > reservation? I am no memblock expert, so I don't know. > > > I didn't run into any issues, as my MIPS platform is non-DT, but I > > > assume arch/arm64/mm/init.c:reserve_elfcorehdr() had the check for > > > a reason. > > > > The memory will be reserved regardless of the earlier reservation, the > > issue may appear when the reservations are made for different purpose. E.g. > > if there was crash kernel allocation before the reservation of elfcorehdr. > > > > The check in such case will prevent the second reservation, but, at least > > in arch/arm64/mm/init.c:reserve_elfcorehdr() it does not seem to prevent > > different users of the overlapping regions to step on each others toes. > > If the kernel has been passed in overlapping regions, is there > anything you can do other than hope to get a message out? Nothing really. I've been thinking about adding flags to memblock.reserved to at least distinguish firmware regions from the kernel allocations, but I never got to that. > > Moreover, arm64::reserve_elfcorehdr() seems buggy to me, because of there > > is only a partial overlap of the elfcorehdr with the previous reservation, > > the non-overlapping part of elfcorehdr won't get reserved at all. > > What do you suggest as the arm64 version is not the common version? I'm not really familiar with crash dump internals, so I don't know if resetting elfcorehdr_addr to ELFCORE_ADDR_ERR is a good idea. I think at least arm64::reserve_elfcorehdr() should reserve the entire elfcorehdr area regardless of the overlap. Otherwise it might get overwritten by a random memblock_alloc(). > Rob -- Sincerely yours, Mike.
On Mon, Aug 23, 2021 at 4:52 PM Rob Herring <robh@kernel.org> wrote: > On Mon, Aug 23, 2021 at 5:13 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > On Sun, Aug 15, 2021 at 5:25 PM Rob Herring <robh@kernel.org> wrote: > > > On Wed, Aug 11, 2021 at 10:50:58AM +0200, Geert Uytterhoeven wrote: > > > > This patch series adds generic support for parsing DT properties related > > > > to crash dump kernels ("linux,elfcorehdr" and "linux,elfcorehdr" under > > > > the "/chosen" node), makes use of it on arm32, and performs a few > > > > cleanups. It is an evolution of the combination of [1] and [2]. > > > > > > The DT bits look fine to me. How do you expect this to be merged? I'm > > > happy to take it if arch maintainers can ack it. > > > > I had hoped you could take the series... > > My current thought is I'll take 2-5, 7 and 8 given that's what I have > acks for and the others can be applied independently. Note that Palmer did ack patch 6, so you can include it. Russell: any thoughts about patch 9? Thanks! > > > > The series consists of 6 parts: > > > > 1. Patch 1 prepares architecture-specific code (needed for MIPS only) > > > > to avoid duplicating elf core header reservation later. > > > > 2. Patch 2 prepares the visibility of variables used to hold > > > > information retrieved from the DT properties. > > > > 3. Patches 3-5 add support to the FDT core for handling the > > > > properties. > > > > This can co-exist safely with architecture-specific handling, until > > > > the latter has been removed. > > > > > > Looks like patch 5 doesn't have any dependencies with the series? > > > > Indeed. So you can take it independently. > > > > > > 4. Patch 6 removes the non-standard handling of "linux,elfcorehdr" on > > > > riscv. > > > > > > I thought this should be applied for 5.14? > > > > Me too, but unfortunately that hasn't happened yet... > > Buried in the middle of this series is not going to encourage it to be > picked up as a fix. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Tue, Aug 24, 2021 at 6:55 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > On Mon, Aug 23, 2021 at 4:52 PM Rob Herring <robh@kernel.org> wrote: > > On Mon, Aug 23, 2021 at 5:13 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > > On Sun, Aug 15, 2021 at 5:25 PM Rob Herring <robh@kernel.org> wrote: > > > > On Wed, Aug 11, 2021 at 10:50:58AM +0200, Geert Uytterhoeven wrote: > > > > > This patch series adds generic support for parsing DT properties related > > > > > to crash dump kernels ("linux,elfcorehdr" and "linux,elfcorehdr" under > > > > > the "/chosen" node), makes use of it on arm32, and performs a few > > > > > cleanups. It is an evolution of the combination of [1] and [2]. > > > > > > > > The DT bits look fine to me. How do you expect this to be merged? I'm > > > > happy to take it if arch maintainers can ack it. > > > > > > I had hoped you could take the series... > > > > My current thought is I'll take 2-5, 7 and 8 given that's what I have > > acks for and the others can be applied independently. > > Note that Palmer did ack patch 6, so you can include it. Right, but Palmer should have taken it if it's for 5.14. Anyways, I've now applied patches 2-8. If we want to improve the handling over what arm64 code did as discussed, I think that's a separate patch anyways. Rob