Re: [PATCH 07/11] ppc64/kexec_file: add support to relocate purgatory

[kernel test robot <lkp@intel.com>]

[-- Attachment #1: Type: text/plain, Size: 8685 bytes --]

Hi Hari,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on linux/master linus/master v5.8-rc2 next-20200626]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Hari-Bathini/ppc64-enable-kdump-support-for-kexec_file_load-syscall/20200627-030901
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-allmodconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

>> arch/powerpc/kexec/file_load_64.c:711:47: warning: parameter names (without types) in function declaration
     711 | static unsigned int local_entry_offset(struct mem_sym *UNUSED(sym))
         |                                               ^~~~~~~
>> arch/powerpc/kexec/file_load_64.c:711:47: warning: 'struct mem_sym' declared inside parameter list will not be visible outside of this definition or declaration
   arch/powerpc/kexec/file_load_64.c: In function 'kexec_do_relocs_ppc64':
>> arch/powerpc/kexec/file_load_64.c:791:29: error: passing argument 1 of 'local_entry_offset' from incompatible pointer type [-Werror=incompatible-pointer-types]
     791 |   val += local_entry_offset(sym);
         |                             ^~~
         |                             |
         |                             const Elf64_Sym * {aka const struct elf64_sym *}
   arch/powerpc/kexec/file_load_64.c:711:56: note: expected 'struct mem_sym * (*)()' but argument is of type 'const Elf64_Sym *' {aka 'const struct elf64_sym *'}
     711 | static unsigned int local_entry_offset(struct mem_sym *UNUSED(sym))
         |                                        ~~~~~~~~~~~~~~~~^~~~~~~~~~~
   arch/powerpc/kexec/file_load_64.c: At top level:
   arch/powerpc/kexec/file_load_64.c:1124:5: warning: no previous prototype for 'arch_kimage_file_post_load_cleanup' [-Wmissing-prototypes]
    1124 | int arch_kimage_file_post_load_cleanup(struct kimage *image)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/local_entry_offset +791 arch/powerpc/kexec/file_load_64.c

   679	
   680	/* Helper functions to apply relocations */
   681	static int do_relative_toc(unsigned long val, uint16_t *loc,
   682				   unsigned long mask, int complain_signed)
   683	{
   684		if (complain_signed && (val + 0x8000 > 0xffff)) {
   685			pr_err("TOC16 relocation overflows (%lu)\n", val);
   686			return -ENOEXEC;
   687		}
   688	
   689		if ((~mask & 0xffff) & val) {
   690			pr_err("Bad TOC16 relocation (%lu)\n", val);
   691			return -ENOEXEC;
   692		}
   693	
   694		*loc = (*loc & ~mask) | (val & mask);
   695		return 0;
   696	}
   697	#ifdef PPC64_ELF_ABI_v2
   698	/* PowerPC64 specific values for the Elf64_Sym st_other field.  */
   699	#define STO_PPC64_LOCAL_BIT	5
   700	#define STO_PPC64_LOCAL_MASK	(7 << STO_PPC64_LOCAL_BIT)
   701	#define PPC64_LOCAL_ENTRY_OFFSET(other)					\
   702		(((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) \
   703		 >> 2) << 2)
   704	
   705	static unsigned int local_entry_offset(const Elf64_Sym *sym)
   706	{
   707		/* If this symbol has a local entry point, use it. */
   708		return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
   709	}
   710	#else
 > 711	static unsigned int local_entry_offset(struct mem_sym *UNUSED(sym))
   712	{
   713		return 0;
   714	}
   715	#endif
   716	
   717	/**
   718	 * kexec_do_relocs_ppc64 - Apply relocations based on relocation type.
   719	 * @my_r2:                 TOC pointer.
   720	 * @sym:                   Symbol to relocate.
   721	 * @r_type:                Relocation type.
   722	 * @loc:                   Location to modify.
   723	 * @val:                   Relocated symbol value.
   724	 * @addr:                  Final location after relocation.
   725	 *
   726	 * Returns 0 on success, negative errno on error.
   727	 */
   728	static int kexec_do_relocs_ppc64(unsigned long my_r2, const Elf_Sym *sym,
   729					 int r_type, void *loc, unsigned long val,
   730					 unsigned long addr)
   731	{
   732		int ret = 0;
   733	
   734		switch (r_type) {
   735		case R_PPC64_ADDR32:
   736			/* Simply set it */
   737			*(uint32_t *)loc = val;
   738			break;
   739	
   740		case R_PPC64_ADDR64:
   741			/* Simply set it */
   742			*(uint64_t *)loc = val;
   743			break;
   744	
   745		case R_PPC64_REL64:
   746			*(uint64_t *)loc = val - (uint64_t)loc;
   747			break;
   748	
   749		case R_PPC64_REL32:
   750			/* Convert value to relative */
   751			val -= (unsigned long)loc;
   752			if (val + 0x80000000 > 0xffffffff) {
   753				pr_err("REL32 %li out of range!\n", val);
   754				return -ENOEXEC;
   755			}
   756	
   757			*(uint32_t *)loc = val;
   758			break;
   759	
   760		case R_PPC64_TOC:
   761			*(uint64_t *)loc = my_r2;
   762			break;
   763	
   764		case R_PPC64_TOC16:
   765			ret = do_relative_toc(val - my_r2, loc, 0xffff, 1);
   766			break;
   767	
   768		case R_PPC64_TOC16_DS:
   769			ret = do_relative_toc(val - my_r2, loc, 0xfffc, 1);
   770			break;
   771	
   772		case R_PPC64_TOC16_LO:
   773			ret = do_relative_toc(val - my_r2, loc, 0xffff, 0);
   774			break;
   775	
   776		case R_PPC64_TOC16_LO_DS:
   777			ret = do_relative_toc(val - my_r2, loc, 0xfffc, 0);
   778			break;
   779	
   780		case R_PPC64_TOC16_HI:
   781			ret = do_relative_toc((val - my_r2) >> 16, loc,
   782					      0xffff, 0);
   783			break;
   784	
   785		case R_PPC64_TOC16_HA:
   786			ret = do_relative_toc((val - my_r2 + 0x8000) >> 16, loc,
   787					      0xffff, 0);
   788			break;
   789	
   790		case R_PPC64_REL24:
 > 791			val += local_entry_offset(sym);
   792			/* Convert value to relative */
   793			val -= addr;
   794			if (val + 0x2000000 > 0x3ffffff || (val & 3) != 0) {
   795				pr_err("REL24 %li out of range!\n", val);
   796				return -ENOEXEC;
   797			}
   798	
   799			/* Only replace bits 2 through 26 */
   800			*(uint32_t *)loc = ((*(uint32_t *)loc & ~0x03fffffc) |
   801					    (val & 0x03fffffc));
   802			break;
   803	
   804		case R_PPC64_ADDR16_LO:
   805			*(uint16_t *)loc = val & 0xffff;
   806			break;
   807	
   808		case R_PPC64_ADDR16_HI:
   809			*(uint16_t *)loc = (val >> 16) & 0xffff;
   810			break;
   811	
   812		case R_PPC64_ADDR16_HA:
   813			*(uint16_t *)loc = (((val + 0x8000) >> 16) & 0xffff);
   814			break;
   815	
   816		case R_PPC64_ADDR16_HIGHER:
   817			*(uint16_t *)loc = (((uint64_t)val >> 32) & 0xffff);
   818			break;
   819	
   820		case R_PPC64_ADDR16_HIGHEST:
   821			*(uint16_t *)loc = (((uint64_t)val >> 48) & 0xffff);
   822			break;
   823	
   824			/* R_PPC64_REL16_HA and R_PPC64_REL16_LO are handled to support
   825			 * ABIv2 r2 assignment based on r12 for PIC executable.
   826			 * Here address is known, so replace
   827			 *	0:	addis 2,12,.TOC.-0b@ha
   828			 *		addi 2,2,.TOC.-0b@l
   829			 * by
   830			 *		lis 2,.TOC.@ha
   831			 *		addi 2,2,.TOC.@l
   832			 */
   833		case R_PPC64_REL16_HA:
   834			/* check that we are dealing with the addis 2,12 instruction */
   835			if (((*(uint32_t *)loc) & 0xffff0000) != 0x3c4c0000) {
   836				pr_err("Unexpected instruction for  R_PPC64_REL16_HA");
   837				return -ENOEXEC;
   838			}
   839	
   840			val += my_r2;
   841			/* replacing by lis 2 */
   842			*(uint32_t *)loc = 0x3c400000 + ((val >> 16) & 0xffff);
   843			break;
   844	
   845		case R_PPC64_REL16_LO:
   846			/* check that we are dealing with the addi 2,2 instruction */
   847			if (((*(uint32_t *)loc) & 0xffff0000) != 0x38420000) {
   848				pr_err("Unexpected instruction for R_PPC64_REL16_LO");
   849				return -ENOEXEC;
   850			}
   851	
   852			val += my_r2 - 4;
   853			*(uint16_t *)loc = val & 0xffff;
   854			break;
   855	
   856		default:
   857			pr_err("Unknown rela relocation: %d\n", r_type);
   858			ret = -ENOEXEC;
   859			break;
   860		}
   861	
   862		return ret;
   863	}
   864	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 69557 bytes --]