Hi Mathieu, Thanks for your thorough review. While thinking about it,there is at least another option which would consist in splitting all elf specific functions into a separate .h file and then include it in a .c to "instantiate" the functions with correct types. For instance, it would look like this: #define ELF_TYPE 32 #include "elf_functions.h" #undef ELF_TYPE #define ELF_TYPE 64 #include "elf_functions.h" pros: More readable and type-checking ok cons: A bit hackish I would say this might be a better optino than my current patch. However, I'm not sure this kind of thing of well accepted in the kernel. Clément ----- On 24 Jan, 2020, at 22:58, Mathieu Poirier mathieu.poirier@xxxxxxxxxx wrote: > On Fri, Jan 24, 2020 at 09:24:16AM +0100, Clément Leger wrote: >> Hi Mathieu, >> >> ----- On 24 Jan, 2020, at 01:53, Mathieu Poirier mathieu.poirier@xxxxxxxxxx >> wrote: >> >> > Hi Clement, >> > >> > On Fri, Oct 04, 2019 at 08:42:20PM +0200, Clement Leger wrote: >> >> elf32 and elf64 mainly differ by their types. In order to avoid >> >> copy/pasting the whole loader code, generate static inline functions >> >> which will access values according to the elf class. It allows to keep a >> >> common loader basis. >> >> In order to accomodate both elf types sizes, the maximum size for a >> >> elf header member is chosen using the maximum value of both elf class. >> >> >> >> Signed-off-by: Clement Leger <cleger@xxxxxxxxx> >> >> Tested-by: Arnaud POULIQUEN <arnaud.pouliquen@xxxxxx> >> >> --- >> >> Changes in v2: >> >> - Add ELF64 support in documentation >> >> >> > >> > First and foremost please address the complaints from checkpatch. >> >> I fixed one typo in accommodate. The other checkpatch complaint is >> about missing parenthesis for macros with complex values which is >> unfortunately not possible since I'm generating inline functions. >> >> Did you have any other one ? >> >> > >> >> --- >> >> Documentation/remoteproc.txt | 2 +- >> >> drivers/remoteproc/remoteproc_elf_loader.c | 135 ++++++++++++++++++----------- >> >> drivers/remoteproc/remoteproc_elf_loader.h | 69 +++++++++++++++ >> >> drivers/remoteproc/remoteproc_internal.h | 2 +- >> >> drivers/remoteproc/st_remoteproc.c | 2 +- >> >> include/linux/remoteproc.h | 4 +- >> >> 6 files changed, 157 insertions(+), 57 deletions(-) >> >> create mode 100644 drivers/remoteproc/remoteproc_elf_loader.h >> >> >> >> diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt >> >> index 77fb03acdbb4..bf4f0c41ec4e 100644 >> >> --- a/Documentation/remoteproc.txt >> >> +++ b/Documentation/remoteproc.txt >> >> @@ -230,7 +230,7 @@ in the used rings. >> >> Binary Firmware Structure >> >> ========================= >> >> >> >> -At this point remoteproc only supports ELF32 firmware binaries. However, >> >> +At this point remoteproc supports ELF32 and ELF64 firmware binaries. However, >> >> it is quite expected that other platforms/devices which we'd want to >> >> support with this framework will be based on different binary formats. >> >> >> >> diff --git a/drivers/remoteproc/remoteproc_elf_loader.c >> >> b/drivers/remoteproc/remoteproc_elf_loader.c >> >> index b17d72ec8603..6a2d31d6092c 100644 >> >> --- a/drivers/remoteproc/remoteproc_elf_loader.c >> >> +++ b/drivers/remoteproc/remoteproc_elf_loader.c >> >> @@ -31,6 +31,7 @@ >> >> #include <linux/elf.h> >> >> >> >> #include "remoteproc_internal.h" >> >> +#include "remoteproc_elf_loader.h" >> >> >> >> /** >> >> * rproc_elf_sanity_check() - Sanity Check ELF firmware image >> >> @@ -43,8 +44,16 @@ int rproc_elf_sanity_check(struct rproc *rproc, const struct >> >> firmware *fw) >> >> { >> >> const char *name = rproc->firmware; >> >> struct device *dev = &rproc->dev; >> >> + /* >> >> + * Elf files are beginning with the same structure. Thus, to simplify >> >> + * header parsing, we can use the elf32_hdr one for both elf64 and >> >> + * elf32. >> >> + */ >> >> struct elf32_hdr *ehdr; >> >> + u32 elf_shdr_size; >> >> + u64 phoff, shoff; >> >> char class; >> >> + u16 phnum; >> >> >> >> if (!fw) { >> >> dev_err(dev, "failed to load %s\n", name); >> >> @@ -58,9 +67,13 @@ int rproc_elf_sanity_check(struct rproc *rproc, const struct >> >> firmware *fw) >> > >> > In the current code [1] fw->size is compared against the size of an elf32_hdr. >> > If support for elf64 is added that code needs to be modified to check for the >> > right header size using fw_elf_get_class(). >> >> Actually, the elf32 header is smaller than the elf64 one so this check is >> there to ensure that we have at least a minimal elf header (elf32). >> And since the class is derived from the header, you better have to check the >> header size before accessing it. >> >> To be more clear, I could compare it to min(sizeof(struct elf32_hdr), >> sizeof(struct elf64_hdr)) or add a comment at least stating that since >> elf header contains the same fields for identification, we can use the >> elf32 one. >> >> > >> > [1] >> > https://elixir.bootlin.com/linux/v5.5-rc6/source/drivers/remoteproc/remoteproc_elf_loader.c#L46 >> > >> >> >> >> ehdr = (struct elf32_hdr *)fw->data; >> >> >> >> - /* We only support ELF32 at this point */ >> >> + if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) { >> >> + dev_err(dev, "Image is corrupted (bad magic)\n"); >> >> + return -EINVAL; >> >> + } >> >> + >> > >> > Is there a reason to move this check up where? If not please bring it back to >> > its original location, that is below: >> > >> > "if (fw->size < ehdr->e_shoff + sizeof(structelf32_shdr))" >> > >> >> This is because the new check for size uses elf_shdr_size which is derived from >> the class. And since the class is extracted from the elf header, we need to >> check >> the header to be correct first. >> >> >> class = ehdr->e_ident[EI_CLASS]; >> >> - if (class != ELFCLASS32) { >> >> + if (class != ELFCLASS32 && class != ELFCLASS64) { >> >> dev_err(dev, "Unsupported class: %d\n", class); >> >> return -EINVAL; >> >> } >> >> @@ -75,26 +88,29 @@ int rproc_elf_sanity_check(struct rproc *rproc, const struct >> >> firmware *fw) >> >> return -EINVAL; >> >> } >> >> >> >> - if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) { >> >> - dev_err(dev, "Image is too small\n"); >> >> - return -EINVAL; >> >> - } >> >> + phoff = elf_hdr_e_phoff(class, fw->data); >> >> + shoff = elf_hdr_e_shoff(class, fw->data); >> >> + phnum = elf_hdr_e_phnum(class, fw->data); >> >> + elf_shdr_size = elf_size_of_shdr(class); >> >> >> >> - if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) { >> >> - dev_err(dev, "Image is corrupted (bad magic)\n"); >> >> + if (fw->size < shoff + elf_shdr_size) { >> >> + dev_err(dev, "Image is too small\n"); >> >> return -EINVAL; >> >> } >> >> >> >> - if (ehdr->e_phnum == 0) { >> >> + if (phnum == 0) { >> >> dev_err(dev, "No loadable segments\n"); >> >> return -EINVAL; >> >> } >> >> >> >> - if (ehdr->e_phoff > fw->size) { >> >> + if (phoff > fw->size) { >> >> dev_err(dev, "Firmware size is too small\n"); >> >> return -EINVAL; >> >> } >> >> >> >> + dev_dbg(dev, "Firmware is an elf%d file\n", >> >> + class == ELFCLASS32 ? 32 : 64); >> >> + >> > >> > Yes, this is useful. >> > >> >> return 0; >> >> } >> >> EXPORT_SYMBOL(rproc_elf_sanity_check); >> >> @@ -110,11 +126,9 @@ EXPORT_SYMBOL(rproc_elf_sanity_check); >> >> * Note that the boot address is not a configurable property of all remote >> >> * processors. Some will always boot at a specific hard-coded address. >> >> */ >> >> -u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw) >> >> +u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw) >> >> { >> >> - struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data; >> >> - >> >> - return ehdr->e_entry; >> >> + return elf_hdr_e_entry(fw_elf_get_class(fw), fw->data); >> >> } >> >> EXPORT_SYMBOL(rproc_elf_get_boot_addr); >> >> >> >> @@ -145,37 +159,41 @@ EXPORT_SYMBOL(rproc_elf_get_boot_addr); >> >> int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw) >> >> { >> >> struct device *dev = &rproc->dev; >> >> - struct elf32_hdr *ehdr; >> >> - struct elf32_phdr *phdr; >> >> + const void *ehdr, *phdr; >> >> int i, ret = 0; >> >> + u16 phnum; >> >> const u8 *elf_data = fw->data; >> >> + u8 class = fw_elf_get_class(fw); >> >> + u32 elf_phdr_size = elf_size_of_phdr(class); >> >> >> >> - ehdr = (struct elf32_hdr *)elf_data; >> >> - phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff); >> >> + ehdr = elf_data; >> >> + phnum = elf_hdr_e_phnum(class, ehdr); >> >> + phdr = elf_data + elf_hdr_e_phoff(class, ehdr); >> >> >> >> /* go through the available ELF segments */ >> >> - for (i = 0; i < ehdr->e_phnum; i++, phdr++) { >> >> - u32 da = phdr->p_paddr; >> >> - u32 memsz = phdr->p_memsz; >> >> - u32 filesz = phdr->p_filesz; >> >> - u32 offset = phdr->p_offset; >> >> + for (i = 0; i < phnum; i++, phdr += elf_phdr_size) { >> >> + u64 da = elf_phdr_p_paddr(class, phdr); >> >> + u64 memsz = elf_phdr_p_memsz(class, phdr); >> >> + u64 filesz = elf_phdr_p_filesz(class, phdr); >> >> + u64 offset = elf_phdr_p_offset(class, phdr); >> >> + u32 type = elf_phdr_p_type(class, phdr); >> >> void *ptr; >> >> >> >> - if (phdr->p_type != PT_LOAD) >> >> + if (type != PT_LOAD) >> >> continue; >> >> >> >> - dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n", >> >> - phdr->p_type, da, memsz, filesz); >> >> + dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n", >> >> + type, da, memsz, filesz); >> >> >> >> if (filesz > memsz) { >> >> - dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n", >> >> + dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n", >> >> filesz, memsz); >> >> ret = -EINVAL; >> >> break; >> >> } >> >> >> >> if (offset + filesz > fw->size) { >> >> - dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n", >> >> + dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n", >> >> offset + filesz, fw->size); >> >> ret = -EINVAL; >> >> break; >> >> @@ -184,14 +202,15 @@ int rproc_elf_load_segments(struct rproc *rproc, const >> >> struct firmware *fw) >> >> /* grab the kernel address for this device address */ >> >> ptr = rproc_da_to_va(rproc, da, memsz); >> >> if (!ptr) { >> >> - dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz); >> >> + dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da, >> >> + memsz); >> >> ret = -EINVAL; >> >> break; >> >> } >> >> >> >> /* put the segment where the remote processor expects it */ >> >> - if (phdr->p_filesz) >> >> - memcpy(ptr, elf_data + phdr->p_offset, filesz); >> >> + if (filesz) >> >> + memcpy(ptr, elf_data + offset, filesz); >> >> >> >> /* >> >> * Zero out remaining memory for this segment. >> >> @@ -208,24 +227,32 @@ int rproc_elf_load_segments(struct rproc *rproc, const >> >> struct firmware *fw) >> >> } >> >> EXPORT_SYMBOL(rproc_elf_load_segments); >> >> >> >> -static struct elf32_shdr * >> >> -find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size) >> >> +static const void * >> > >> > Not sure I understand the "const" - was the compiler complaining? >> >> It's actually caused by the fact I used a const void* shdr in the caller. >> I will check if this is mandatory. >> >> > >> >> +find_table(struct device *dev, const struct firmware *fw) >> >> { >> >> - struct elf32_shdr *shdr; >> >> + const void *shdr, *name_table_shdr; >> >> int i; >> >> const char *name_table; >> >> struct resource_table *table = NULL; >> >> - const u8 *elf_data = (void *)ehdr; >> >> + const u8 *elf_data = (void *)fw->data; >> >> + u8 class = fw_elf_get_class(fw); >> >> + size_t fw_size = fw->size; >> >> + const void *ehdr = elf_data; >> >> + u16 shnum = elf_hdr_e_shnum(class, ehdr); >> >> + u32 elf_shdr_size = elf_size_of_shdr(class); >> >> + u16 shstrndx = elf_hdr_e_shstrndx(class, ehdr); >> >> >> >> /* look for the resource table and handle it */ >> >> - shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff); >> >> - name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset; >> >> + shdr = elf_data + elf_hdr_e_shoff(class, ehdr); >> >> + name_table_shdr = shdr + (shstrndx * elf_shdr_size); >> >> + name_table = elf_data + elf_shdr_sh_offset(class, name_table_shdr); >> > >> > It took me a while but I figured out what is happening here. To save me (and >> > other people) from going through the same mental process every time I look at >> > this code, please add a comment for each of the above 3 lines. >> >> Indeed. >> >> > >> >> >> >> - for (i = 0; i < ehdr->e_shnum; i++, shdr++) { >> >> - u32 size = shdr->sh_size; >> >> - u32 offset = shdr->sh_offset; >> >> + for (i = 0; i < shnum; i++, shdr += elf_shdr_size) { >> >> + u64 size = elf_shdr_sh_size(class, shdr); >> >> + u64 offset = elf_shdr_sh_offset(class, shdr); >> >> + u32 name = elf_shdr_sh_name(class, shdr); >> >> >> >> - if (strcmp(name_table + shdr->sh_name, ".resource_table")) >> >> + if (strcmp(name_table + name, ".resource_table")) >> >> continue; >> >> >> >> table = (struct resource_table *)(elf_data + offset); >> >> @@ -279,21 +306,21 @@ find_table(struct device *dev, struct elf32_hdr *ehdr, >> >> size_t fw_size) >> >> */ >> >> int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw) >> >> { >> >> - struct elf32_hdr *ehdr; >> >> - struct elf32_shdr *shdr; >> >> + const void *shdr; >> >> struct device *dev = &rproc->dev; >> >> struct resource_table *table = NULL; >> >> const u8 *elf_data = fw->data; >> >> size_t tablesz; >> >> + u8 class = fw_elf_get_class(fw); >> >> + u64 sh_offset; >> >> >> >> - ehdr = (struct elf32_hdr *)elf_data; >> >> - >> >> - shdr = find_table(dev, ehdr, fw->size); >> >> + shdr = find_table(dev, fw); >> >> if (!shdr) >> >> return -EINVAL; >> >> >> >> - table = (struct resource_table *)(elf_data + shdr->sh_offset); >> >> - tablesz = shdr->sh_size; >> >> + sh_offset = elf_shdr_sh_offset(class, shdr); >> >> + table = (struct resource_table *)(elf_data + sh_offset); >> >> + tablesz = elf_shdr_sh_size(class, shdr); >> >> >> >> /* >> >> * Create a copy of the resource table. When a virtio device starts >> >> @@ -326,13 +353,17 @@ EXPORT_SYMBOL(rproc_elf_load_rsc_table); >> >> struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc, >> >> const struct firmware *fw) >> >> { >> >> - struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data; >> >> - struct elf32_shdr *shdr; >> >> + const void *shdr; >> >> + u64 sh_addr, sh_size; >> >> + u8 class = fw_elf_get_class(fw); >> >> >> >> - shdr = find_table(&rproc->dev, ehdr, fw->size); >> >> + shdr = find_table(&rproc->dev, fw); >> >> if (!shdr) >> >> return NULL; >> >> >> >> - return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size); >> >> + sh_addr = elf_shdr_sh_addr(class, shdr); >> >> + sh_size = elf_shdr_sh_size(class, shdr); >> >> + >> >> + return rproc_da_to_va(rproc, sh_addr, sh_size); >> > >> > The prototype for the above is as follow: >> > >> > void *rproc_da_to_va(struct rproc *rproc, u64 da, int len) >> > >> > But sh_size is a u64, which will cause problem that are hard to debug. I think >> > it is better to move 'len' to an 8 byte type along with the refactoring of the >> > existing code that is implied. I suggest to split this work in a preparatory >> > patch (that will still be part of this set). >> >> Nice catch ! I will do that. >> >> > >> >> } >> >> EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table); >> >> diff --git a/drivers/remoteproc/remoteproc_elf_loader.h >> >> b/drivers/remoteproc/remoteproc_elf_loader.h >> >> new file mode 100644 >> >> index 000000000000..fac3565734f9 >> >> --- /dev/null >> >> +++ b/drivers/remoteproc/remoteproc_elf_loader.h >> >> @@ -0,0 +1,69 @@ >> >> +/* SPDX-License-Identifier: GPL-2.0 */ >> >> +/* >> >> + * Remote processor elf loader defines >> >> + * >> >> + * Copyright (C) 2019 Kalray, Inc. >> >> + */ >> >> + >> >> +#ifndef REMOTEPROC_ELF_LOADER_H >> >> +#define REMOTEPROC_ELF_LOADER_H >> >> + >> >> +#include <linux/elf.h> >> >> +#include <linux/types.h> >> >> + >> >> +/** >> >> + * fw_elf_get_class - Get elf class >> >> + * @fw: the ELF firmware image >> >> + * >> >> + * Note that we use and elf32_hdr to access the class since the start of the >> >> + * struct is the same for both elf class >> >> + * >> >> + * Return: elf class of the firmware >> >> + */ >> >> +static inline u8 fw_elf_get_class(const struct firmware *fw) >> >> +{ >> >> + struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data; >> >> + >> >> + return ehdr->e_ident[EI_CLASS]; >> >> +} >> >> + >> >> +#define ELF_GET_FIELD(__s, __field, __type) \ >> >> +static inline __type elf_##__s##_##__field(u8 class, const void *arg) \ >> >> +{ \ >> >> + if (class == ELFCLASS32) \ >> >> + return (__type) ((const struct elf32_##__s *) arg)->__field; \ >> >> + else \ >> >> + return (__type) ((const struct elf64_##__s *) arg)->__field; \ >> >> +} >> >> + >> >> +ELF_GET_FIELD(hdr, e_entry, u64) >> >> +ELF_GET_FIELD(hdr, e_phnum, u16) >> >> +ELF_GET_FIELD(hdr, e_shnum, u16) >> >> +ELF_GET_FIELD(hdr, e_phoff, u64) >> >> +ELF_GET_FIELD(hdr, e_shoff, u64) >> >> +ELF_GET_FIELD(hdr, e_shstrndx, u16) >> >> + >> >> +ELF_GET_FIELD(phdr, p_paddr, u64) >> >> +ELF_GET_FIELD(phdr, p_filesz, u64) >> >> +ELF_GET_FIELD(phdr, p_memsz, u64) >> >> +ELF_GET_FIELD(phdr, p_type, u32) >> >> +ELF_GET_FIELD(phdr, p_offset, u64) >> >> + >> >> +ELF_GET_FIELD(shdr, sh_size, u64) >> >> +ELF_GET_FIELD(shdr, sh_offset, u64) >> >> +ELF_GET_FIELD(shdr, sh_name, u32) >> >> +ELF_GET_FIELD(shdr, sh_addr, u64) >> > >> > I like how you did this. >> > >> >> + >> >> +#define ELF_STRUCT_SIZE(__s) \ >> >> +static inline unsigned long elf_size_of_##__s(u8 class) \ >> >> +{ \ >> >> + if (class == ELFCLASS32)\ >> >> + return sizeof(struct elf32_##__s); \ >> >> + else \ >> >> + return sizeof(struct elf64_##__s); \ >> >> +} >> >> + >> >> +ELF_STRUCT_SIZE(shdr) >> >> +ELF_STRUCT_SIZE(phdr) >> >> + >> >> +#endif /* REMOTEPROC_ELF_LOADER_H */ >> >> diff --git a/drivers/remoteproc/remoteproc_internal.h >> >> b/drivers/remoteproc/remoteproc_internal.h >> >> index 45ff76a06c72..4ef745e3a1bc 100644 >> >> --- a/drivers/remoteproc/remoteproc_internal.h >> >> +++ b/drivers/remoteproc/remoteproc_internal.h >> >> @@ -63,7 +63,7 @@ phys_addr_t rproc_va_to_pa(void *cpu_addr); >> >> int rproc_trigger_recovery(struct rproc *rproc); >> >> >> >> int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw); >> >> -u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw); >> >> +u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw); >> >> int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw); >> >> int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw); >> >> struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc, >> >> diff --git a/drivers/remoteproc/st_remoteproc.c >> >> b/drivers/remoteproc/st_remoteproc.c >> >> index 51049d17b1e5..e23abd8a96b0 100644 >> >> --- a/drivers/remoteproc/st_remoteproc.c >> >> +++ b/drivers/remoteproc/st_remoteproc.c >> >> @@ -193,7 +193,7 @@ static int st_rproc_start(struct rproc *rproc) >> >> } >> >> } >> >> >> >> - dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr); >> >> + dev_info(&rproc->dev, "Started from 0x%llx\n", rproc->bootaddr); >> >> >> >> return 0; >> >> >> >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h >> >> index 04d04709f2bd..512de9a2590c 100644 >> >> --- a/include/linux/remoteproc.h >> >> +++ b/include/linux/remoteproc.h >> >> @@ -362,7 +362,7 @@ struct rproc_ops { >> >> struct rproc *rproc, const struct firmware *fw); >> >> int (*load)(struct rproc *rproc, const struct firmware *fw); >> >> int (*sanity_check)(struct rproc *rproc, const struct firmware *fw); >> >> - u32 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw); >> >> + u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw); >> >> }; >> >> >> >> /** >> >> @@ -478,7 +478,7 @@ struct rproc { >> >> int num_traces; >> >> struct list_head carveouts; >> >> struct list_head mappings; >> >> - u32 bootaddr; >> >> + u64 bootaddr; >> >> struct list_head rvdevs; >> >> struct list_head subdevs; >> >> struct idr notifyids; >> > >> > Please hold off before doing another respin of this patch. While doing >> > something completely different I noticed TI also did some work in this area. >> > I'd like to take some time to look at their implementation and see if they carry >> > features that haven't been included here. I intend to do this tomorrow. >> >> Ok, >> >> Thanks for your review, > > As promised I looked at what Suman had done on his side [1] to support 64-bit > ELF > files. His approach to offer the same functionality but for 64 bit in a new file > is quick, simple and flexible. On the flip side it introduces code duplication, > something that is seriously frowned upon upstream. > > I did some soul searching in the kernel code and found very little in terms of > implementation that deals with both 32 and 64 bit ELF format. The most > convincing approach was set forth by the MIPS guys [2]. They too have decided > to support both types in the same functions, but I don't see us adding an if() > statement (and the code duplication that comes with it) every time we need to > deal with file types. > > Given the above I'm in favour of moving forward with your approach. One could > rightly argue the macros make the code harder to read but given the > alternatives, it seems to be the best solution. > > Mathieu > > [1]. https://bit.ly/2Rpmb4E > [2]. https://elixir.bootlin.com/linux/v5.5-rc6/source/arch/mips/kernel/elf.c#L75 >> >> Clément >> >> > >> > Thanks, >> > Mathieu >> > >> >> -- > > >> 2.15.0.276.g89ea799