From b4c7ab816b48e0d2dd15753c0329bd4aa59f713f Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 27 Feb 2024 06:43:53 -1000 Subject: [PATCH] linux-user/elfload: Write process memory to core file in larger chunks We do not need to copy pages from guest memory before writing them out. Because vmas are contiguous in host memory, we can write them in one go. Signed-off-by: Richard Henderson --- linux-user/elfload.c | 27 ++++----------------------- 1 file changed, 4 insertions(+), 23 deletions(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index b8d07d8054..491e754f72 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -4551,32 +4551,13 @@ static int elf_core_dump(int signr, const CPUArchState *env) } /* - * Finally we can dump process memory into corefile as well. + * Finally write process memory into the corefile as well. */ for (vma = vma_first(&mm); vma != NULL; vma = vma_next(vma)) { - abi_ulong addr; - abi_ulong end; + size_t size = vma_dump_size(vma); - end = vma->vma_start + vma_dump_size(vma); - - for (addr = vma->vma_start; addr < end; - addr += TARGET_PAGE_SIZE) { - char page[TARGET_PAGE_SIZE]; - int error; - - /* - * Read in page from target process memory and - * write it to coredump file. - */ - error = copy_from_user(page, addr, sizeof (page)); - if (error != 0) { - (void) fprintf(stderr, "unable to dump " TARGET_ABI_FMT_lx "\n", - addr); - errno = -error; - goto out; - } - if (dump_write(fd, page, TARGET_PAGE_SIZE) < 0) - goto out; + if (size && dump_write(fd, g2h_untagged(vma->vma_start), size) < 0) { + goto out; } } errno = 0;